text:
German/Appendices/Vocabulary/Animals

Bugs

 * (1-23) das Insekt (-en): insect

 * (1) die Libelle (-n): dragonfly
 * (2) die Heuschrecke (-n): grasshopper
 * (3) die Grille (-n): cricket
 * (4) die Küchenschabe (-n): cockroach
 * (5) die Gottesanbeterin (-nen): praying mantis
 * (6) die Termite (-n): termite

 * (7) der Floh (-"e): flea
 * (8) die Laus (-"e): louse
 * (9) die Fliege (-n): fly
 * (10) die Mücke (-n): mosquito

 * (11-14) der Käfer (-): beetles
 * (11) der Mistkäfer (-): dung beetle
 * (12) der Marienkäfer (-): ladybug
 * (13) der Leuchtkäfer (-): firefly
 * (14) der Hirschkäfer (-): stag beetle

 * (15) die Raupe (-n): caterpillar
 * (16) die Puppe (-n): chrysalis
 * (17) der Schmetterling (-e): butterfly
 * (18) die Seidenraupe (-n): silkworm
 * (19) der Kokon (-s): cocoon
 * (20) die Motte (-n): moth

 * (21) die Ameise (-n): ant
 * (22) die Biene (-n): bee
 * (23) die Wespe (-n): wasp

External Links - References

 * Marine Species List
 * Wikipedia Portal For Amphibians & Reptiles
 * Taxonomic List @Bird Photography
 * Alphabetic List @Bird Photography
 * A-Z Common British Birds List
 * A-Z WildLife Birds

Vocabulary/Animals

title: German/Appendices/Vocabulary/Animals


text:
User talk:Vankhieu

Welcome!
Welcome, Vankhieu!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally.-- – Mike.lifeguard  | talk 01:41, 24 March 2008 (UTC)

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: User talk:Vankhieu


text: User talk:203.148.187.139

title: User talk:203.148.187.139


text:
User talk:200.251.69.131

qEPFwo j09ham0ht0o

title: User talk:200.251.69.131


text:
User talk:Conmon~enwikibooks

Welcome, Conmon!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. – Mike.lifeguard  | talk 03:41, 24 March 2008 (UTC)

Please note that we don't accept game guides. Doom Modding is borderline; I'm not sure what the community will think of it. Feel free to ask at WB:HELP for advice regarding that book. – Mike.lifeguard  | talk 03:41, 24 March 2008 (UTC)

Your account will be renamed
Hello,

The developer team at Wikimedia is making some changes to how accounts work, as part of our on-going efforts to provide new and better tools for our users like cross-wiki notifications. These changes will mean you have the same account name everywhere. This will let us give you new features that will help you edit and discuss better, and allow more flexible user permissions for tools. One of the side-effects of this is that user accounts will now have to be unique across all 900 Wikimedia wikis. See the announcement for more information.

Unfortunately, your account clashes with another account also called Conmon. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Conmon~enwikibooks that only you will have. If you like it, you don't have to do anything. If you do not like it, you can pick out a different name.

Your account will still work as before, and you will be credited for all your edits made so far, but you will have to use the new account name when you log in.

Sorry for the inconvenience.

Yours, Keegan Peterzell Community Liaison, Wikimedia Foundation 23:03, 17 March 2015 (UTC)

Renamed
 This account has been renamed as part of single-user login finalisation. If you own this account you can |log in using your previous username and password for more information. If you do not like this account's new name, you can choose your own using this form after logging in: . -- Keegan (WMF) (talk) 04:48, 19 April 2015 (UTC)

title: User talk:Conmon~enwikibooks


text:
Wikijunior:Famous Inventors

Welcome to the world of Famous Inventors. What is the story behind some of the greatest inventions? This book will tell you about advances in technology, a biography of who invented them, how they were discovered, and how they have helped you and me.

Table of Contents

 * 1) Title Page
 * 2) /Early Inventors/
 * 3) Archimedes
 * 4) Galileo
 * 5) Antonie van Leeuwenhoek
 * 6) /Inventors in Communication/
 * 7) Telephone
 * 8) Alexander Graham Bell
 * 9) Samuel Morse
 * 10) Radio
 * 11) Nikola Tesla
 * 12) Guglielmo Marconi
 * 13) /Inventors in Transportation/
 * 14) Thomas Telford
 * 15) George Stephenson
 * 16) James Starley
 * 17) Werner von Siemens
 * 18) Frank J. Sprague
 * 19) Henry Ford
 * 20) Wilber and Orville Wright
 * 21) Robert H. Goddard
 * 22) Clive Sinclair
 * 23) /Inventors in Agriculture/
 * 24) George Washington Carver
 * 25) Cyrus McCormick
 * 26) Eli Whitney
 * 27) /Inventors in Everyday Uses/
 * 28) Thomas Edison
 * 29) Benjamin Franklin
 * 30) Lewis Howard Latimer
 * 31) George Westinghouse
 * 32) /Inventors in Medicine/
 * 33) Marie Curie

Please copy this stub template onto new inventors pages. /stub template/

title: Wikijunior:Famous Inventors


text:
User talk:207.112.26.93

Welcome!
Welcome to Wikibooks, a collection of open-content textbooks! You don't have to log in to read or edit articles on Wikibooks, but creating an account is quick, free and non-intrusive, requires no personal information, and gives you many benefits, including:
 * The use of a username of your choice
 * The ability to view all your contributions via a "My contributions" link
 * Your own user page
 * Your own talk page which, if you choose, also allows users to send you messages without knowing your e-mail address
 * The use of your own personal watchlist to which you can add articles that interest you
 * The ability to rename pages.
 * The ability to upload images
 * The ability to customize the appearance and behavior of the website
 * The eligibility to become an administrator
 * The right to be heard in votes and elections
 * Your IP address will no longer be visible to other users.

We hope that you choose to become a Wikibookian and create an account. Feel free to ask me any questions you may have on my talk page. By the way, make sure to sign your posts and comments with four tildes (~~~~), which will let others know who left it.

– Mike.lifeguard  | talk 04:00, 24 March 2008 (UTC)

Caught Short
This seems to be fiction, which is not what Wikibooks is for. It will be deleted imminently. – Mike.lifeguard  | talk 04:00, 24 March 2008 (UTC)

title: User talk:207.112.26.93


text:
User talk:Speirs

Welcome, Speirs!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. – Mike.lifeguard  | talk 04:17, 24 March 2008 (UTC)

Inclusion policy
Please do read our inclusion policy. While Caught Short may be public domain and non-fiction, it is still not suitable for inclusion here. Please add it to Wikisource instead. They deal specifically with public domain source texts, while Wikibooks is for collaborative development of free textbooks. Thanks! – Mike.lifeguard  | talk 04:17, 24 March 2008 (UTC)

title: User talk:Speirs


text:
Cookbook:Nasi Goreng (Indonesian Fried Rice)

| Cuisine of Indonesia

Ingredients

 * 2 servings of steamed rice
 * 2 eggs
 * 1 clove garlic
 * 2 shallots
 * 1 red chile pepper
 * 1 Tbsp fish oil
 * 10 ml coconut oil
 * Sweet soy sauce
 * Salty soy sauce or salt
 * Ground pepper

Optional ingredients

 * 20 stink beans or green beans
 * 100 g chicken fillet, cut into small pieces
 * 100 g small prawns
 * 4 fish meatballs
 * 2 spoons of tinned corned beef
 * 1 cucumber
 * Sliced hot dogs or sausages
 * Sliced chicken liver
 * Cauliflower
 * Sliced salted dried fish
 * Spring onion

Procedure

 * 1) Slice shallots and red pepper into thin slices.
 * 2) Crush garlic, peel of the skin, and mince well.
 * 3) Slice stinky beans in half, or as desired.
 * 4) Heat oil in wok, add the chicken or prawn, and stir fry until done.
 * 5) Add shallot, pepper, garlic and stink beans. Stir until garlic turns golden.
 * 6) Crack in the eggs, and stir fry until half done.
 * 7) Add the steamed rice, and stir until all mixed.
 * 8) Add soy sauces, salt, and ground pepper as desired.
 * 9) Serve on plates, adding fresh cucumber slices or tomatoes as garnish.

Notes, tips, and variations

 * Use cold rice, preferably leftover from a day before. Unsticky rice is easier to cook and preferred by some.
 * Some prefer not to use stinky beans and use green peas or green beans as a substitute. This will give a nice shade of green.

Variations

 * If you are cooking with corned beef, leave the sweet soy sauce out. This is a variation of nasi goreng called nasi goreng kornet or corned beef fried rice.
 * Try including a fried egg, sunny side up, as accompaniment on the side.
 * You can use salted fish as a variation to make nasi goreng ikan asin, or salted fish fried rice. In this case, leave out the sweet soy sauce.
 * Substitute green peas with sliced spring onions, adding them after the rice has been added to the wok. Spring onions will give nice aroma and color to the fried rice.
 * Prawn cracker/chips are a nice condiment on the side.

சமையல் நூல்/மரக்கறி நாசி கொரெங்


text:
User talk:Raddy

Welcome message
Welcome, Raddy!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. Webaware talk 08:51, 24 March 2008 (UTC)

title: User talk:Raddy


text:
A-level Physics (Advancing Physics)/Vectors

What is a vector?
Two types of physical quantity are scalars and vectors. Scalar quantities are simple: they are things like speed, distance, or time. They have a magnitude, but no direction. A vector quantity consists of two parts: both a scalar and a direction. For example, the velocity of an object is made up of both the speed of an object and the direction in which it is moving. Speed is a scalar; add a direction and it becomes velocity, a vector. Similarly, take a distance and give it a direction and it becomes a displacement, such as '2 miles south-east'. Distance is a scalar, whereas displacement is a vector.

Vectors and scalars are both useful. For example, if I run around the room several times and end up back where I started, I may have covered a distance of 50m. My displacement is 0 - the null vector. The null vector is the only vector which has no direction. If I want to calculate how much work I have done, I should use the distance. If I want to know where I am, I should use the displacement.

As we shall see, the directional component of a vector can be expressed in several different ways. '2 miles south-east' is the same as saying '2 miles on a bearing of 135°', or '1.4 miles east, -1.4 miles north'. The scalar component of a vector is known as the modulus of a vector.

Vector Notation
You need to be able to understand the following algebraic representations of vectors:

Vector Components
Sometimes, it is useful to express a vector in terms of two other vectors. These two vectors are usually pointing up and right, and work similarly to the Cartesian co-ordinate system. So, for example, 'an acceleration of 3.4 ms−2 west' becomes 'a vertical acceleration of 0 ms−2 and an horizontal acceleration of -3.4 ms−2 east. However, this is a very simple example.

Consider the diagram on the right. The vector a consists of a vertical component j and a horizontal component i. a has a modulus |a|. |i| and |j| can be calculated using |a|, the angle between i and a θ and some basic trigonometry. We know that:

$$\cos{\theta} = \frac{|\mathbf{i}|}{|\mathbf{a}|}$$ and $$\sin{\theta} = \frac{|\mathbf{j}|}{|\mathbf{a}|}$$

Hence:

 * i| = |a| cos θ and |j| = |a| sin θ.

This will be given to you in the formula booklet in the exam.

Vector Addition
You also need to know how to add vectors together. This enables us to answer questions such as, "If I travel 5 miles north-west and then 6 miles east, where am I?", or "If I accelerate at 3 ms-2 in a northerly direction, and accelerate south-east at 1 ms-2, what is my total acceleration?". Vectors can be added 'tip-to-tail'; that is to say, the resultant vector is equal to 'travelling' the first vector, and then travelling the second vector.

This is shown in the diagram on the left. When vectors a and b are added together, the resultant vector a + b is produced, joining the tail of the first vector to the tip of the last, with the vectors joined together. In practise, the easiest way to add two vectors together is to calculate (if you do not already know this) the vertical and horizontal components, and add them all together to get two total vertical and horizontal components. You can then use Pythagoras' theorem to calculate the modulus of the resultant vector, and some more basic trigonometry to calculate its direction.

In algebra:

$$\sum{|\mathbf{a}|_n} = \sqrt{(\sum{|\mathbf{i}|_n})^2 + (\sum{|\mathbf{j}|_n})^2}$$ and $$\theta = \arctan{\frac{\sum{|\mathbf{j}|_n}}{\sum{|\mathbf{i}|_n}}}$$,

where a1 ... an are the vectors to be added together, i1 ... in are their horizontal components, j1 ... jn are their vertical components, and θ is the angle between the θ=0 line and the resultant vector Σan, as shown in the diagram on the right.

Predicting Parabolas
If you use a diagram to represent vectors (making the lengths of the arrows proportional to the modulus of the vectors they represent, and the directions equal), you can predict graphically the trajectory an object (such as a ball) will take. Use the following steps: $$\Delta \mathbf{v} = \frac{\Delta \mathbf{s}}{\Delta t} = \frac{\Delta \mathbf{s}}{1} = \Delta \mathbf{s}$$
 * Draw a vector to represent the velocity of the ball (in ms−1). Since this is the number of metres travelled in 1 second, and each step of the process is 1 second long, this vector represents both the velocity and the displacement of the ball, i.e.
 * Copy this vector, and connect its tail to the tip of the first vector. This new vector represents the velocity and displacement that the ball would have had over the next second, if gravity did not exist.
 * Draw another vector to represent the change in velocity due to gravity (9.81 ms−2) on Earth. This should be pointing downwards, and be to the same scale as the other vectors. This represents the fact that the velocity of the ball changes due to gravity (velocity is a vector, so both the speed and angle of the ball's travel change).
 * Add these vectors together, as shown above, to give a new vector. This new vector represents the velocity and displacement of the ball over the second second.
 * Repeat this process until the ball hits something (draw the ground, if in doubt).

Questions
1. Which of the following are vectors?

 * 20 cm
 * 9.81 ms−2 towards the centre of the earth
 * 5 km south-east
 * 500 ms−1 on a bearing of 285.3°

2. A displacement vector a is the resultant vector of two other vectors, 5 m north and 10 m south-east. What does a equal, as a displacement and a bearing?

3. If I travel at a velocity of 10 ms−1 on a bearing of 030°, at what velocity am I travelling north and east?

4. An alternative method of writing vectors is in a column, as follows:

$$\mathbf{a} = \binom{x}{y}$$,

where x and y are the vertical and horizontal components of the vector respectively. Express |a| and the angle between a and $$\tbinom{1}{0}$$ in terms of x and y.

5. A more accurate method of modelling the trajectory of a ball is to include air resistance as a constant force F. How would this be achieved?

/Worked Solutions/


text:
A-level Physics (Advancing Physics)/Vectors/Trigonometry

Trigonometry is the study of the ratios between sides on a right-angled triangle. Consider the following diagram:

Depending on the value of the angle BAC, the ratios between the three sides of the triangle will vary. These three sides are generally given the names 'hypotenuse' (H), 'opposite' (O) and 'adjacent' (A). The opposite side is opposite the angle being considered. The hypotenuse is the side opposite the right angle, and the adjacent side is the remaining side, which is also next to the angle being considered.

The three basic trigonometric ratios, in relation to an acute angle θ, are the sine, cosine and tangent ratios, as follows:

$$\sin{\theta} = \frac{O}{H}$$

$$\cos{\theta} = \frac{A}{H}$$

$$\tan{\theta} = \frac{O}{A}$$

It is often helpful to remember them by using the mnemonic 'SOH-CAH-TOA'.

These ratios can be calculated using the appropriate buttons on a scientific calculator. In addition, if you already know the ratio between two sides, and wish to calculate the angle from it, you can use the sin−1, cos−1 and tan−1 buttons to use the inverse function. These functions are technically known as arcsin, arccosin and arctan.


text:
Radiation Oncology/Hyperthermia/Randomized

Hyperthermia Randomized Evidence

RT +/- Hyperthermia

 * Duke (1994-2001)
 * Randomized. 109 patients with superficial tumors (<= 3cm depth); breast 65%, H&N 13%, melanoma 10%. Tumors had to be "heatable" on initial HT. Arm 1) RT alone vs. Arm 2) RT + HT. Hyperthermia to >43C x1 hour, 2x/week. RT dose 30-60 Gy if previous RT, otherwise 60-70 Gy in 1.8-2.0 Gy/fx
 * 2005 PMID 15860867 -- "Randomized trial of hyperthermia and radiation for superficial tumors." (Jones EL, J Clin Oncol. 2005 May 1;23(13):3079-85.)
 * Outcome: CR RT 42% vs. RT+HT 66% (SS). Patients with prior RT had most benefit (68% vs. 23%, SS)
 * Toxicity: Well tolerated, 1 Grade III thermal burn
 * Conclusion: Significant local control benefit for HT

 * International Collaborative Hyperthermia Group (1988-1991) -- combined results from five Phase III trials
 * Randomized. 5 trials merged due to slow accrual, closed early after benefit. 306 patients. Advanced primary or recurrent BCA; 50% active disease outside treatment area. Could have had prior RT. Trials: Dutch Hyperthermia Group (DHG), Medical Research Council (MRC BrI and BrR), European Society of Hyperthermic Oncology (ESHO), and Princes Margaret (PMH). Target hyperthermia 43C. RT given in various fractions.
 * 1996 PMID 8690639 -- "Radiotherapy with or without hyperthermia in the treatment of superficial localized breast cancer: results from five randomized controlled trials. International Collaborative Hyperthermia Group." (Vernon CC, Int J Radiat Oncol Biol Phys. 1996 Jul 1;35(4):731-44.)
 * Outcome: CR RT 41% vs. RT+HT 59% (SS); greatest effect in recurrent lesions in previous RT, where re-irradiation dose was low. 2-year OS ~40% (NS), 74% patients progressed outside HT area during follow-up
 * Conclusion: Combined result demonstrated efficacy of hyperthermia as adjunct to RT for treatment of recurrence


text:
C Sharp Programming/The .NET Framework/Collections

Lists
A list is a dynamic array that resizes itself as needed, if more data is inserted than it can hold at the time of insertion. Items can be inserted at any index, deleted at any index and accessed at any index. The C# non-generic list class is the, while the generic one is.

Many of the class' methods and properties are demonstrated in the following example:

The terminal output is:

List demo | bread | butter | chocolate | roast beef | tomato | vanilla cake | yoghurt | The list now has 0 items.

LinkedLists
Items in a linked list can be accessed directly only one after the other. Of course an item at any index can be accessed, but the list must iterate to the item from the first one, which is much slower than accessing items by index in an array or a list. There is no non-generic linked list in C#, while the generic one is.

Queues
A queue is a FIFO (first in - first out) collection. The item first pushed in the queue gets taken first with the pop function. Only the first item is accessible at any time, and items can only be put to the end. The non-generic queue class is called Queue, while the generic one is.

Stacks
A stack is a LIFO (last in - first out) collection. The item pushed in first will be the last to be taken by pop. Only the last item is accessible at any time, and items can only be put at the top. The non-generic stack class is Stack, while the generic one is.

Hashtables and dictionaries
A dictionary is a collection of values with keys. The values can be very complex, yet searching the keys is still fast. The non-generic class is, while the generic one is.


text:
A-level Physics (Advancing Physics)/Vectors/Worked Solutions

1. Which of the following are vectors?

 * 20 cm is scalar, not a vector - it does not have a directional component.
 * 9.81 ms−2 towards the centre of the earth is a vector.
 * 5 km south-east is a vector.
 * 500 ms−1 on a bearing of 285.3° is a vector.

2. A displacement vector a''' is the resultant vector of two other vectors, 5 m north and 10 m south-east. What does a equal, as a displacement and a bearing?'''

So, for the resultant vector:

$$\mbox{Horizontal displacement } = 0 + \frac{10}{\sqrt{2}} \approx 7.07\mbox{ m}$$

$$\mbox{Vertical displacement } = 5 - \frac{10}{\sqrt{2}} \approx -2.07\mbox{ m}$$

This gives us a right-angled triangle. So:

$$\theta = \arctan{\frac{2.07}{7.07}} \approx 16.3$$°, so the bearing equals 90° + 16.3° = 106.3°.

$$\mbox{Resultant displacement} = \sqrt{7.07^2 + (-2.07)^2} \approx 7.4\mbox{ m}$$

3. If I travel at a velocity of 10 ms−1 on a bearing of 030°, at what velocity am I travelling north and east?

$$\mbox{Vertical velocity (North)} = 10 \times \cos{30} = 5\sqrt{3}\mbox{ ms}^{-1} \approx 8.66\mbox{ ms}^{-1}$$

$$\mbox{Horizontal velocity (East)} = 10 \times \sin{30} = 5\mbox{ ms}^{-1}$$

4. An alternative method of writing vectors is in a column, as follows:

$$\mathbf{a} = \binom{x}{y}$$,

'''where x and y are the vertical and horizontal components of the vector respectively. Express |a| and the angle between a and $$\tbinom{1}{0}$$ in terms of x and y.'''

By Pythagoras' theorem:

$$(| \mathbf{a} |)^2 = x^2 + y^2$$

$$| \mathbf{a} | = \sqrt{x^2 + y^2}$$

Let θ be the angle between a and $$\tbinom{1}{0}$$.

$$\tan{\theta} = \frac{y}{x}$$

$$\theta = \arctan{\frac{y}{x}}$$

This angle θ is known as the argument of a.

5. A more accurate method of modelling the trajectory of a ball is to include air resistance as a constant force F'''. How would this be achieved?'''

Once the arrow representing the acceleration due to gravity has been added on, add an horizontal arrow pushing against the motion of the ball. Since F = ma, the magnitude of this acceleration is F divided by m.

Note that this model is still not perfect. In fact, F is not constant - it depends on the horizontal component of the ball's velocity.


text: Wikibooks:Requests for deletion/Emergency Operation Centre GIS


text:
The Sway Reference Manual/Debugging

At this point in time, you should be able to write some sophisticated Sway programs. In addition, I'm sure you are incorporating some sophisticated bugs, as well. Such is the life of a programmer!

There are two types of errors typically encountered in programming, syntax errors, in which the source code has problems and cannot be compiled and executed, and semantic errors, in which, the code runs (after a fashion) and then terminates too early or produces the wrong result.

Human languages have syntax and semantic errors. Here are some examples:

The box mxyskd the water.

This sentence is not valid English since token 'mxyskd' is not a word. This is a syntactic error.

The box drank water the

This sentence is also not valid English since the article 'the' is out of place and there is no punctuation to indicate the end of the sentence. These are also syntactic errors.

The box drank the water.

This sentence is syntactically correct, but doesn't make sense semantically: boxes usually don't drink.

Programming languages have errors similar to these and we will explore how detect and fix them in the subsequent sections.

As you learn these techniques, remember, the number one rule of debugging is to catch errors as early as possible. That is, find the smallest improvement to your code that gets you a a step closer to the final version, then implement, test, and debug that step. Then repeat.

Woe to the student that attempts to write the whole project before testing!

Syntax Errors
Syntax errors always look something like this:

SYNTAX ERROR: :syntaxError file prog1.s,line 113 expecting OPEN_PARENTHESIS, found function instead error occurred prior to: ;[END OF LINE]

A file name and line number is given by the error report. Usually this is exactly where the problem is but realize that this point is where the error was detected; the problem may have started earlier in the file.

Many of the non-obvious errors involve putting a semicolon in the wrong place or omitting one where it is necessary. Remember, semicolons do not follow named function definitions and certain function calls like ifs and whiles. In the next chapter, you will learn which function calls need to be followed by semicolons and which do not.

If you have a strange syntax error that you cannot track down, try commenting out pieces of the code until the error goes away. The error is likely within the code just commented out.

Sway has three kinds of comments. The first is the end-of-line comment. Anything on the line after a double slash (two consecutive forward slashes) is ignored.

//removing the next function

//function id(x) { x; }

The second is the triple slash. This causes the rest of the file to be ignored and is quite useful for debugging syntax.

///removing the rest of the file function id(x) { x; } To use the triple slash, start with the /// at the very top of the file so that the whole file is ignored. This should remove the syntax error. Then keep moving the /// downward into the file until the syntax error appears. It is likely that the newly uncovered section of code contains the error.

The final kind of comment is the block comment. Anything appearing between a slash-star and a star-slash is ignored:

/* removing this function

function id(x) { x; }

*/

Note that a block comment cannot contain another block comment.

Semantic Errors
Syntax errors are found when the Sway interpreter reads your code, while semantic errors are found while the interpreter is evaluating code. Semantic error reports look like:

EVALUATION ERROR: :mathError file prog1.s,line 3: division: cannot divide by zero

CALL TRACE: initial call: prog1.s,line 5: inspect(f(3)); in ... prog1.s,line 3: x / 0;

The file name and line number are given; like syntax errors, this is where the semantic error was detected. Following the description of the error comes a call trace. The call trace is read from top to bottom. In the example, the problem started on line 5 when the inspect function was called. This call triggered a call to the function f where the actual divide-by-zero was attempted on line 3. The call trace is extremely useful for tracking down problems.

Semantic errors usually occur when an important variable ends up having a different value than you expected. Therefore, it is important to see the values of your variables when debugging your code.

Print statements
You should get into the habit of being able to 'visualize' the state of your program. For example, suppose you wish to see the value of a variable named x at a number of different points in your program. The simplest visualization is a print statement of the form:

println("x is ",x);

I must comment, as a teacher, how rarely students make use of this simple tool. You should liberally use print statements to debug your semantic errors.

It gets rather tedious to add print statements of this sort, however, since you are only going to delete those lines once you solve the problem. What's needed is a faster way to add print statements Once such faster way is the inspect function. For example, the following two function calls are equivalent:

println("x is ",x); inspect(x);

The output of both calls is exactly the same. If the value of x is 5, then the output of both calls is:

x is 5

Now the amount of time saved by using inspect isn't much in this case (a savings of typing eight characters fewer), but the savings grow when the expression to be inspected gets complicated. Consider these calls:

println("alpha . beta(gama,delta) is ",alpha . beta(gama,delta)); inspect(alpha . beta(gama,delta));

Again, the output of each are identical, but the savings have grown when using inspect.

Finally, if even inspect is too much to write, define a variable such as vv, for view variable:

var vv = inspect;

and use it instead of inspect:

vv(x);

Tracing a function call
Sometimes it is useful to trace the execution of a function call, line by line. Suppose you wish to call a function named f and trace each line of the function as it executes. Simply wrap the call with statements that set the filter component of the function.

f. filter = trace*; y = f(x); f. filter = :null;

or more simply, using the wrapper function trace::

y = trace(f(x));

Settng the filter to trace* (which trace does) turns on tracing of the called function; setting the filter to null turns off tracing. You will need to include the debug library at the top of your file. For example, this program:

include("debug");

function f(x) {       var a = x + 1; var b = x - 1; a * b;       }

var result = trace(f(5));

inspect(result);

yields the following output:

prog.s,line 5: var a = x + 1; prog.s,line 6: var b = x - 1; prog.s,line 7: a * b;    result is 24

If you set the filter to trace, each line of traced function's body will be displayed. You will need to press the  key to move on to the next line in the function.

If you set a function's filter to trace* instead, your program will pause after printing out the traced statement, as with trace. The difference is f you type any character other than whitespace and hit return, you will be thrown into a miniature Sway interpreter. Here you can do nearly anything you can do in the interactive Sway interpreter. The only difference is that each definition or expression to be executed must be entered on a single line.

Stepping through functions
Stepping through functions is similar to tracing, expect your program will pause before each statement is executed. If you simply press , the current statement is executed, the next statement is displayed (if it exists), and the program pauses again.

However, if you type anything else during the pause, your input is evaluated as a Sway expression and the result displayed. This evaluation is performed under the environment in force during the evaluation of the function body. In other words, you can examine (and modify) the variables in scope during the function call. This mini-interpreter keeps on running until you stop entering expressions to evaluate. When you stop entering expressions, the program advances to the next line in the function call.

Setting up stepping through a function is similar to tracing:

f. filter = step*; y = f(x); f. filter = :null;

or more simply, using the wrapper function step::

y = step(f(x));

In the interaction (as above, but using step), the value a is examined and b is modified:

prog.s,line 5: var a = x + 1;> prog.s,line 6: var b = x - 1;> a;   INTEGER: 6 >    prog.s,line 6: var b = x - 1;> prog.s,line 7: a * b;> b = 10; INTEGER: 10 > b;   INTEGER: 10 >    prog.s,line 7: a * b;> result is 60

Note that the line presented at any given point has not yet been executed. Thus, we had to wait until the variable a was declared until we could examine it. As with tracing, you must include the debug library to use stepping.

The main difference between the mini-interpreter and the Sway interpreter is that the expression passed to the mini-interpreter must be entered all on one line.

You can exit the mini-interpreter by entering a  or by entering a blank line.

Breakpoints
Sometimes, you know exactly where in a function you wish to pause and examine variables. Rather than use step, you can call the mini-interpreter directly by using the sway function.

include("debug");

function f(x) {       var a = x + 1; var b = x - 1; println("breakpoint!"); sway;                 //call the mini-interpreter println("done."); a * b;       }

var result = f(5);

inspect(result);

Running this program yields:

breakpoint! sway> a;   INTEGER: 6 sway> b = 10; INTEGER: 10; sway> done. result is 60

Like before, input to the mini-interpreter must be entered on a single line.

The sway function is built-in; thus, you do not need to include debug.

Assertions
There are two kinds of errors you must deal with. The first is the user of your program has supplied erroneous input. These kinds of errors are known as external errors. 'Bulletproofing' your code means adding the logic to deal external errors.

The second kind of errors arise from errors in the code itself. These are known as internal errors. A good Computer scientist anticipates that these errors will happen no matter how good a programmer he or she is and will use assertions to find these errors early. For example, suppose you 'know' that the input to a function is always a non-negative integer. You can use an assertion to detect variations from this constraint:

function f(x) {       assert(x >= 0); ...       }

During the development of code, the assertions make sure you haven't called such functions inappropriately.

When you are finished with your code, you may comment out your assertions.

title: The Sway Reference Manual/Debugging


text:
User:AzaToth/twinklexfd.js

// If TwinkleConfig aint exist. if( typeof( TwinkleConfig ) == 'undefined' ) { TwinkleConfig = function {}; }

/** TwinkleConfig.summaryAd (string) If ad should be added or not to summary, default TWINKLE */ if( typeof( TwinkleConfig.summaryAd ) == 'undefined' ) { TwinkleConfig.summaryAd = " using TW"; } function twinklexfd { if( wgNamespaceNumber < 0 || wgCurRevisionId == false ) { return; }	if (twinkleConfigExists) {		mw.util.addPortletLink( 'p-cactions', "javascript:twinklexfd.callback", "xfd", "tw-xfd", "Anything for deletion", ""); }	else {		mw.util.addPortletLink('p-cactions', 'javascript:alert("Your account is too new to use Twinkle.");', 'xfd', 'tw-xfd', 'Anything for deletion', ''); } } $(twinklexfd);

twinklexfd.callback = function twinklexfdCallback {

var Window = new SimpleWindow( 600, 300 ); Window.setTitle( "Anything for deletion" ); var form = new QuickForm( twinklexfd.callback.evaluate ); var categories = form.append( {			type: 'select',			name: 'category',			label: 'Select wanted type of deletion: ',			event: twinklexfd.callback.change_category		} ); categories.append( {			type: 'option',			label: 'VfD',			value: 'vfd',			tooltip: 'Votes for deletion'		} ); categories.append( {			type: 'option',			label: 'Speedy',			value: 'speedy',			tooltip: 'Speedy deletions'		} );

form.append( {			type: 'field',			label:'Work area',			name: 'work_area'		} );

var result = form.render; Window.setContent( result ); Window.display;

// We must init the var evt = document.createEvent( "Event" ); evt.initEvent( 'change', true, true ); result.category.dispatchEvent( evt );

}

twinklexfd.callback.change_category = function twinklexfdCallbackChangeCategory(e) { var value = e.target.value; var root = e.target.form; var old_area; var childNodes = root.childNodes; for( var i = 0; i < childNodes.length; ++i ) { var node = childNodes[i]; if( 			node instanceof Element &&			node.getAttribute( 'name' ) == 'work_area' 		) { old_area = node; break; }	}	var work_area = null;

switch( value ) { case 'vfd': work_area = new QuickForm.element( { 				type: 'field',				label: 'Votes for deletion',				name: 'work_area'			} ); work_area.append( {				type: 'textarea',				name: 'xfdreason',				label: 'Reason: '			} ); work_area.append( { type:'submit' } ); work_area = work_area.render; old_area.parentNode.replaceChild( work_area, old_area ); break; case 'speedy_todo': work_area = new QuickForm.element( { 				type: 'field',				label: 'Speedy deletion',				name: 'work_area'			} ); work_area.append( {				type: 'textarea',				name: 'xfdreason',				label: 'Reason: '			} ); work_area.append( { type:'submit' } ); work_area = work_area.render; old_area.parentNode.replaceChild( work_area, old_area ); break; default: work_area = new QuickForm.element( { 				type: 'field',				label: 'Nothing for anything',				name: 'work_area'			} ); work_area = work_area.render; old_area.parentNode.replaceChild( work_area, old_area ); break; } }

twinklexfd.callbacks = { vfd: { taggingPage: function( self ) { var form = self.responseXML.getElementById('editform'); var postData = { 'wpMinoredit': undefined, // Per memo 'wpWatchthis': form.wpWatchthis.checked ? '' : undefined, 'wpStarttime': form.wpStarttime.value, 'wpEdittime': form.wpEdittime.value, 'wpAutoSummary': form.wpAutoSummary.value, 'wpEditToken': form.wpEditToken.value, 'wpSummary': "Nominated for deletion; see \[\[Wikibooks:Votes for deletion#" + wgPageName + '\]\].'+ TwinkleConfig.summaryAd, 'wpTextbox1': " \{\{vfd\}\}\n " + form.wpTextbox1.value };			self.post( postData ); },		todaysList: function( self ) { var form = self.responseXML.getElementById('editform'); var text = form.wpTextbox1.value; text += "\n\{\{subst:vfd2|" + wgPageName + "|text=" + self.params.reason + ". \~\~\~\~\}\}"; var postData = { 'wpMinoredit': form.wpMinoredit.checked ? '' : undefined, 'wpWatchthis': form.wpWatchthis.checked ? '' : undefined, 'wpStarttime': form.wpStarttime.value, 'wpEdittime': form.wpEdittime.value, 'wpAutoSummary': form.wpAutoSummary.value, 'wpEditToken': form.wpEditToken.value, 'wpSummary': "Adding " + wgPageName + '.' + TwinkleConfig.summaryAd, 'wpTextbox1': text };			self.post( postData ); },		userNotification: function( self ) { var form = self.responseXML.getElementById( 'editform' ); var text = form.wpTextbox1.value; text += "\n\{\{subst:Vfd warning|1=" + wgPageName + "|2=\~\~\~\~\}\}"; var postData = { 'wpMinoredit': form.wpMinoredit.checked ? '' : undefined, 'wpWatchthis': form.wpWatchthis.checked ? '' : undefined, 'wpStarttime': form.wpStarttime.value, 'wpEdittime': form.wpEdittime.value, 'wpAutoSummary': form.wpAutoSummary.value, 'wpEditToken': form.wpEditToken.value, 'wpSummary': 'VfD nomination of \[\[' + wgPageName + '\]\].' + TwinkleConfig.summaryAd, 'wpTextbox1': text };			self.post( postData ); }	} }

twinklexfd.callback.evaluate = function(e) {

wgPageName = wgPageName.replace( /_/g, ' ' ); // for queen/king/whatever and country!

var type = e.target.category.value; var reason = e.target.xfdreason.value;

Status.init( e.target );

if( type == null ) { Status.error( 'Error', 'no action given' ); return; }

switch( type ) {

case 'vfd': // VfD

Wikipedia.addCheckpoint; // Tagging page var query = { 'title': wgPageName, 'action': 'submit' };		wikipedia_wiki = new Wikipedia.wiki( 'Tagging page with deletion tag', query, twinklexfd.callbacks.vfd.taggingPage ); wikipedia_wiki.get;

// Adding discussion

query = { 'title': 'Wikibooks:Votes for deletion', 'action': 'submit', };

// Updating data for the action completed event Wikipedia.actionCompleted.redirect = query['title']; Wikipedia.actionCompleted.notice = "Nomination completed, redirecting now to the list of today";

wikipedia_wiki = new Wikipedia.wiki( 'Adding discussion to todays list', query, twinklexfd.callbacks.vfd.todaysList ); wikipedia_wiki.params = { reason:reason }; wikipedia_wiki.get;

var query = { 'action': 'query', 'prop': 'revisions', 'titles': wgPageName, 'rvlimit': 1, 'rvprop': 'user', 'rvdir': 'newer' }		var callback = function( self ) { var xmlDoc = self.responseXML; var user = xmlDoc.evaluate( '//rev/@user', xmlDoc, null, XPathResult.STRING_TYPE, null ).stringValue; var query = { 'title': 'User talk:' + user, 'action': 'submit' };			var wikipedia_wiki = new Wikipedia.wiki( 'Notifying of initial contributor (' + user + ')', query, twinklexfd.callbacks.vfd.userNotification ); wikipedia_wiki.params = self.params; wikipedia_wiki.get; }		var wikipedia_api = new Wikipedia.api( 'Grabbing data of initial contributor', query, callback ); wikipedia_api.params = self.params; wikipedia_api.post;

Wikipedia.removeCheckpoint; break; } }

title: User:AzaToth/twinklexfd.js


text: User:Hyundai/monobook.js

title: User:Hyundai/monobook.js


text: User talk:170.235.0.113

title: User talk:170.235.0.113


text:
Inorganic Chemistry/Chemical Bonding/Ionic Bond

As we know, atoms tend to attain the octet electronic configuration of minimum energy and maximum stability. One way of attaining this configuration is by transfer of electrons between two atoms. This transfer results in the formation of Ionic Bond.


text: Inorganic Chemistry/Chemical Bonding/Fajan's Rule


text: User talk:169.204.239.26

title: User talk:169.204.239.26


text: User talk:24.189.20.159

title: User talk:24.189.20.159


text: User talk:68.162.99.73

title: User talk:68.162.99.73


text: User talk:24.176.37.183

title: User talk:24.176.37.183


text:
Talk:Magic: The Gathering/Riviera Live Draft

Does "draw a card" abilities only apply to private libraries? Or do you have the choice of draft-drawing?


text:
User talk:70.104.155.162

Welcome!
Welcome to Wikibooks, a collection of open-content textbooks! You don't have to log in to read or edit articles on Wikibooks, but creating an account is quick, free and non-intrusive, requires no personal information, and gives you many benefits, including:
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We hope that you choose to become a Wikibookian and create an account. Feel free to ask me any questions you may have on my talk page. By the way, make sure to sign your posts and comments with four tildes (~~~~), which will let others know who left it.

Also, I reverted your edit, use the discussion page when suggesting changes to a page. Thanks! Νεοπτόλεμος ( talk | email | contribs ) 21:40, 24 March 2008 (UTC)

title: User talk:70.104.155.162


text:
User talk:86.17.254.234

Welcome!
Welcome to Wikibooks, a collection of open-content textbooks! You don't have to log in to read or edit articles on Wikibooks, but creating an account is quick, free and non-intrusive, requires no personal information, and gives you many benefits, including:
 * The use of a username of your choice
 * The ability to view all your contributions via a "My contributions" link
 * Your own user page
 * Your own talk page which, if you choose, also allows users to send you messages without knowing your e-mail address
 * The use of your own personal watchlist to which you can add articles that interest you
 * The ability to rename pages.
 * The ability to upload images
 * The ability to customize the appearance and behavior of the website
 * The eligibility to become an administrator
 * The right to be heard in votes and elections
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We hope that you choose to become a Wikibookian and create an account. Feel free to ask me any questions you may have on my talk page. By the way, make sure to sign your posts and comments with four tildes (~~~~), which will let others know who left it.

Νεοπτόλεμος ( talk | email | contribs ) 21:40, 24 March 2008 (UTC)

title: User talk:86.17.254.234


text:
User talk:65.126.207.226

Welcome!
Welcome to Wikibooks, a collection of open-content textbooks! You don't have to log in to read or edit articles on Wikibooks, but creating an account is quick, free and non-intrusive, requires no personal information, and gives you many benefits, including:
 * The use of a username of your choice
 * The ability to view all your contributions via a "My contributions" link
 * Your own user page
 * Your own talk page which, if you choose, also allows users to send you messages without knowing your e-mail address
 * The use of your own personal watchlist to which you can add articles that interest you
 * The ability to rename pages.
 * The ability to upload images
 * The ability to customize the appearance and behavior of the website
 * The eligibility to become an administrator
 * The right to be heard in votes and elections
 * Your IP address will no longer be visible to other users.

We hope that you choose to become a Wikibookian and create an account. Feel free to ask me any questions you may have on my talk page. By the way, make sure to sign your posts and comments with four tildes (~~~~), which will let others know who left it.

title: User talk:65.126.207.226


text: User talk:24.192.196.17

title: User talk:24.192.196.17


text:
User talk:MarkWLewis

My talk page for Wikibooks. Welcome, MarkWLewis!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. Νεοπτόλεμος ( talk | email | contribs ) 22:53, 24 March 2008 (UTC)

title: User talk:MarkWLewis


text:
User:Neoptolemus/monobook.js

// import_script('MediaWiki:Gadget-morebits.js'); import_script('MediaWiki:Gadget-twinklespeedy.js');

title: User:Neoptolemus/monobook.js


text:
Music Theory/How to read Music

This Wikibook is here to give the reader an idea of how to read music; however, this is not to say that this book will teach you to read music correctly. Neither will it teach you to play a musical instrument. Most music related subjects (and most other subjects for that matter) really ought to be studied under a teacher. If you do not want to hire a teacher then this should give you a general idea of how to read music.

Staff

The staff is what every other symbol of musical notation is written on. It consists of 5 lines and 4 spaces that are used to identify which note is meant to be played based on which clef is shown at the beginning of the staff. When a note is too high or too low to be written on one of the lines or spaces (such as Middle C), smaller lines must be written above or below the staff, called "ledger lines".

Clefs
The two most commonly used clefs are the treble clef and a bass clef.

The clefs determine what pitch the notes should fall on; for instance, the treble clef is a G-clef, so wherever the clef ends on is the note G. In the case of treble clef, it is the second line up from the bottom (the end of the clef wraps around the line). The bass clef is an F-clef, so the line between the two dots is the note F. Instruments that use the treble clef include the flute, trumpet, all the saxophones, all the clarinets, guitar (except for the bass), violin, and several others. The bass clef is used for instruments like the bassoon, bass guitar, cello, tuba, and trombone.

For the treble clef, a common mnemonic used to remember which notes correspond to each position would be "Every Good Boy Does Fine" for the notes on the lines (from bottom to top), and "FACE" for notes in the spaces between the lines (from bottom to top). It should be noted that other mnemonics exist, such as "Every Good Bird Does Fly", among others.

Another common mnemonic exists for the bass clef; "All Cows Eat Grass" to remember the notes in the spaces between the lines (bottom to top), and "Good Boys Do Fine Always". Similar to that of the treble clef, there are many such mnemonics, and one is welcome to invent their own to aid themselves should they see fit.

However, it should be noted that these clefs are not the only clefs in existence, with other clefs such as the alto clef and the tenor clef, both using the C-clef, suboctave and sopranino clefs, both using a derivative of the G-clef, or neutral clefs (used in percussion sheet music).

Time Signature

A time signature is usually written as two numbers (one on top of the other) at the beginning of a piece that divides the piece into smaller bits called measures. These make it easier to read and provide hints as to which notes in each measure should be stressed. Measures are broken up using vertical lines that extend from the top line to the bottom line. The top number signifies how many beats each measure will contain, and the bottom note sets down which note will take the value of one beat; so, in 4/4 time, there are four beats in a measure and a quarter note will get one beat. Hence, there will be a time value equal to four quarter notes in every measure. The most common time signatures are 4/4, 3/4, 6/8, and 2/4. Occasionally, there maybe be more than one time signatures denoted (with the time signatures following the second usually being written in brackets). This denotes that the time signature alternates between those time signatures in that order. For example, the figure on the left shows four measures, with the first and third measures being in 4/4 time and the second and fourth measures being in 3/4 time. Sometimes, for ease of reading and counting, an odd time signature (time signature where the numerator does not divide into 2 or 3) may be represented as a compound time signature, with two or more separate time signatures joined with a plus sign, with the option of having multiple numbers on top per time signature also joined with a plus sign. For example, the figure on the left shows two measures in 5/4 time, except that the beats are split into 6 eighth notes (6/8 time) and 2 quarter notes (2/4 time). This compound meter is used in the theme of Mission: Impossible.

Counting
When reading music, you also would need to know how to count, so as to be able to effectively communicate with fellow musicians. The system for counting is relatively simple. For each beat, count upwards numerically (i.e. 1, 2, 3, etc. with 7 being read "sev" to keep everything in one syllable). So two measures of 3/4 time could be counted as "1, 2, 3, 1, 2, 3". If a beat is subdivided into halves, the second subdivided beat is counted as "and" (written as an ampersand "&"). So the same two measures of 3/4 time subdivided into eighth notes (this type of metric modulation is called "double time") would be counted "1 & 2 & 3 & 1 & 2 & 3 &". If a beat is subdivided into thirds, the second and third subdivided beats are counted as "and" and "a" respectively (written "& a"). So the same two measures of 3/4 time subdivided into triplet eighth notes would be counted "1 & a 2 & a 3 & a 1 & a 2 & a 3 & a". Lastly, if a beat is subdivided into quarters, the second, third and fourth subdivided beats are counted as "e", "and" and "a" respectively (written "e & a"). So the same two measures of 3/4 time subdivided into sixteenth notes would be counted "1 e & a 2 e & a 3 e & a" repeated twice. For subdivisions in the reverse direction, one would simply count the beats after dividing them, so a measure of 4/4 time in half time would be counted as "1, 2". If there are further subdivisions beyond quartering the beat, musicians would usually count the beats as if they were metrically modulated so a measure of 2/4 time in octuple time would be counted as "1 e & a 2 e & a 3 e & a 4 e & a" repeated twice (assuming the direction is to count the measure as a compound meter of 8 + 8). For odd subdivisions (not group-able into groups of 2 or 3 beats), the method of counting would depend on the grouping and tempo. For example, if one needs to count 5 eighth notes and the tempo is very slow, one might simply count it as "1, 2, 3, 4, 5". But if the tempo were too fast to count it in that manner, one might count it as "1 e & a &", or "1 & a 2 &" if the direction is to group it as beats of 3 + 2. However, at a very fast tempo, there may be little merit in counting tuplets this way. As such, one is able to use these counting terms to refer to specific beats in a measure. For instance, in the excerpt of music on the right, one might say that the second high C in the second measure of the passage is the "a of beat 4".

Note and Rest Durations

The notes and rests on a staff show the duration of a sound or a pause in the music. There are several different time values of notes and rests; the most basic of which are the whole note (also called semibreve) and rest, each having 4 beats:

The half note (also called minim) and rest, each being half as long as a whole note:

The quarter note (also called crochet) and rest, each being one-quarter the length of the whole note and half the length of a half note:

The eighth note (also called quaver) and rest, each being one-eighth the length of the whole note and half the length of a quarter note:

The sixteenth note (also called semiquaver) and rest, each being one-sixteenth the length of the whole note and half the length of an eighth note:

And so forth with each increasing division getting one extra "flag."

Of course, there are other types of notes, like the breve or the longa, but those aren't as common as these few.

Dotted Notes
Sometimes, note heads may have dots beside them, which denotes that the length of the note is one and a half of its original length. So for instance, a dotted quarter note would have the same note length as a quarter note and an eighth note. Notes can have more than one dots, with the value of the note being modified recursively. For instance, a double dotted quarter note would have the same note length as a quarter note and a dotted eighth note, or a quarter note, an eighth note and a sixteenth note (notice how the "dot" of the quarter note, i.e. the eighth note has become dotted).

title: Music Theory/How to read Music


text: User talk:68.10.212.147

title: User talk:68.10.212.147


text:
Talk:Music Theory/How to read Music

I'm only beginning to write this page/section. I will of course add more to it and clean it up as I go along. I have added it because I felt like the basics were not covered well enough in the rest of the book. Portlandiaman (talk) 16:25, 26 March 2008 (UTC)

title: Talk:Music Theory/How to read Music


text:
MediaWiki:Clearyourcache

Note: After saving, changes may not occur immediately. Click here to learn how to bypass your browser's cache.
 * Mozilla / Firefox / Safari: hold down Shift while clicking Reload, or press Ctrl-Shift-R (Cmd-Shift-R on Apple Mac);
 * Internet Explorer: hold Ctrl while clicking Refresh, or press Ctrl-F5;
 * Konqueror: simply click the Reload button, or press F5;
 * Opera users may need to completely clear their cache in Tools→Preferences.

title: MediaWiki:Clearyourcache


text: User talk:151.203.72.173

title: User talk:151.203.72.173


text:
User talk:75.69.204.103

Welcome!
Welcome to Wikibooks, a collection of open-content textbooks! You don't have to log in to read or edit articles on Wikibooks, but creating an account is quick, free and non-intrusive, requires no personal information, and gives you many benefits, including:
 * The use of a username of your choice
 * The ability to view all your contributions via a "My contributions" link
 * Your own user page
 * Your own talk page which, if you choose, also allows users to send you messages without knowing your e-mail address
 * The use of your own personal watchlist to which you can add articles that interest you
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 * The ability to upload images
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 * The eligibility to become an administrator
 * The right to be heard in votes and elections
 * Your IP address will no longer be visible to other users.

We hope that you choose to become a Wikibookian and create an account. Feel free to ask me any questions you may have on my talk page. By the way, make sure to sign your posts and comments with four tildes (~~~~), which will let others know who left it.

Νεοπτόλεμος ( talk | email | contribs ) 23:34, 24 March 2008 (UTC)

title: User talk:75.69.204.103


text: User talk:74.162.170.177

title: User talk:74.162.170.177


text:
User talk:130.160.47.70

Welcome!
Welcome to Wikibooks, a collection of open-content textbooks! You don't have to log in to read or edit articles on Wikibooks, but creating an account is quick, free and non-intrusive, requires no personal information, and gives you many benefits, including:
 * The use of a username of your choice
 * The ability to view all your contributions via a "My contributions" link
 * Your own user page
 * Your own talk page which, if you choose, also allows users to send you messages without knowing your e-mail address
 * The use of your own personal watchlist to which you can add articles that interest you
 * The ability to rename pages.
 * The ability to upload images
 * The ability to customize the appearance and behavior of the website
 * The eligibility to become an administrator
 * The right to be heard in votes and elections
 * Your IP address will no longer be visible to other users.

We hope that you choose to become a Wikibookian and create an account. Feel free to ask me any questions you may have on my talk page. By the way, make sure to sign your posts and comments with four tildes (~~~~), which will let others know who left it.

Νεοπτόλεμος ( talk | email | contribs ) 00:18, 25 March 2008 (UTC)

--Ramac (talk) 19:42, 17 July 2008 (UTC)

title: User talk:130.160.47.70


text:
User talk:Lusth

Welcome!
Welcome, Lusth!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally.-- – Mike.lifeguard  | talk 00:25, 25 March 2008 (UTC)

SwayBot
Hello John. With a little bit of deduction I assume that this account is run by yourself? Would it be possible for you to provide some more information about what this bot is doing please? It seems to be overwriting pages here with content from another source, which doesn't quite seem in the spirit of this wiki. Also have you read WB:WIW? Your Sway programming language sounds a little bit like original research to me... Although I think I understand the reason's behind including it. Can I ask what you feel the advantage is to using Sway as opposed to an established language as a teaching aid to programming? --AdRiley (talk) 23:19, 6 November 2008 (UTC)

Re: SwayBot
I'm finding Wikibooks very hard to figure out. I assume this is the correct way to reply.

With respect to the bot, I keep the original source on my server under subversion. When I make changes, I first run a script that downloads the book and then checks the book into subversion. If someone besides me has made changes, they get incorporated. If there are conflicts, subversion alerts me and I have to reconcile before I can add my updates. In this way, the bot doesn't trash anybody else's edits.

I know of no other way I can backup the source (wikibooks doesn't seem to allow a download of a complete book) and edit the source with vi (I don't want to learn use a mouse and menu editor and the option to use vim within wikibooks didn't work too well).

Sway is part of an NSF grant on using a functional language with simple syntax and semantics for teaching at-risk students. Although Sway is original research, the textbook is not. It is a deliverable for the grant. Wikibooks seems to be the appropriate venue. Lusth (talk) 23:05, 5 January 2009 (UTC)

editing wikibooks with vim
I'm glad to meet another vim user.

While I don't want to distract you from writing good wikibooks, I thought you might also be interested in:
 * the Wikibook "Learning the vi editor"
 * the Vim Tips wiki

While I've edited wikibooks a lot, and edited lots of files using vim, I still haven't gotten around to editing wikibooks with vim. But I hear that other people edit wikibooks with vim, using something like wikipedia-vim, the WikipediaFS, the "It's All Text" Firefox plugin, or some other text editing technique, or yet more techniques for editing wiki with vim. Please tell me if you find one that works especially well. --DavidCary (talk) 01:30, 17 March 2009 (UTC)

title: User talk:Lusth


text:
User talk:208.120.164.184

Join Us!
-- – Mike.lifeguard  | talk 00:49, 25 March 2008 (UTC)

title: User talk:208.120.164.184


text:
User:DavidChu

Hi, I am David Chu. I am in fourth grade top class. HI ^_^ Sincerely, David Chu

title: User:DavidChu


text:
Inorganic Chemistry/Chemical Bonding/Molecular orbital theory

In chemistry, molecular orbital theory (MO theory) is a method for determining molecular structure in which electrons are not assigned to individual bonds between atoms, but are treated as moving under the influence of the nuclei in the whole molecule. In this theory, each molecule has a set of molecular orbitals, in which it is assumed that the molecular orbital wave function ψf may be written as a simple weighted sum of the n constituent atomic orbitals χi, according to the following equation:

 * $$ \psi_j = \sum_{i=1}^{n} c_{ij} \chi_i$$

The cij coefficients may be determined numerically by substitution of this equation into the Schrödinger equation and application of the variational principle. This method is called the linear combination of atomic orbitals approximation and is used in computational chemistry.

History
Molecular orbital theory was developed, in the years after valence bond theory (1927) had been established, primarily through the efforts of Friedrich Hund, Robert Mulliken, John C. Slater, and John Lennard-Jones. MO theory was originally called the Hund-Mulliken theory. The word orbital was introduced by Mulliken in 1932. By 1933, the molecular orbital theory had become accepted as a valid and useful theory. According to German physicist and physical chemist Erich Hückel, the first quantitative use of molecular orbital theory was the 1929 paper of Lennard-Jones. The first accurate calculation of a molecular orbital wavefunction was that made by Charles Coulson in 1938 on the hydrogen molecule. By 1950, molecular orbitals were completely defined as eigenfunctions (wave functions) of the self-consistent field Hamiltonian and it was at this point that molecular orbital theory became fully rigorous and consistent.

Overview
Molecular orbital (MO) theory uses a linear combination of atomic orbitals to form molecular orbitals which cover the whole molecule. These are often divided into bonding orbitals, anti-bonding orbitals, and non-bonding orbitals. A molecular orbital is merely a Schrödinger orbital which includes several, but often only two nuclei. If this orbital is of type in which the electron(s) in the orbital have a higher probability of being between nuclei than elsewhere, the orbital will be a bonding orbital, and will tend to hold the nuclei together. If the electrons tend to be present in a molecular orbital in which they spend more time elsewhere than between the nuclei, the orbital will function as an anti-bonding orbital and will actually weaken the bond. Electrons in non-bonding orbitals tend to be in deep orbitals (nearly atomic orbitals) associated almost entirely with one nucleus or the other, and thus they spend equal time between nuclei or not. These electrons neither contribute nor detract from bond strength.

Molecular orbitals are further divided according to the types of atomic orbitals combining to form a bond. These orbitals are results of electron-nucleus interactions that are caused by the fundamental force of electromagnetism. Chemical substances will form a bond if their orbitals become lower in energy when they interact with each other. Different chemical bonds are distinguished that differ by electron cloud shape and by energy levels.

MO theory provides a global, delocalized perspective on chemical bonding. For example, in the MO theory for hypervalent molecules, it is no longer necessary to invoke a major role for d-orbitals. In MO theory, any electron in a molecule may be found anywhere in the molecule, since quantum conditions allow electrons to travel under the influence of an arbitrarily large number of nuclei, so long as permitted by certain quantum rules. Although in MO theory some molecular orbitals may hold electrons which are more localized between specific pairs of molecular atoms, other orbitals may hold electrons which are spread more uniformly over the molecule. Thus, overall, bonding (and electrons) are far more delocalized (spread out) in MO theory, than is implied in VB theory. This makes MO theory more useful for the description of extended systems.

An example is that in the MO picture of benzene, composed of a hexagonal ring of 6 carbon atoms. In this molecule, 24 of the 30 total valence bonding electrons are located in 12 σ (sigma) bonding orbitals which are mostly located between pairs of atoms (C-C or C-H), similar to the valence bond picture. However, in benzene the remaining 6 bonding electrons are located in 3 π (pi) molecular bonding orbitals that are delocalized around the ring. Two are in an MO which has equal contributions from all 6 atoms. The other two have a vertical nodes at right angles to each other. As in the VB theory, all of these 6 delocalized pi electrons reside in a larger space which exists above and below the ring plane. All carbon-carbon bonds in benzene are chemically equivalent. In MO theory this is a direct consequence of the fact that the 3 molecular pi orbitals form a combination which evenly spreads the extra 6 electrons over 6 carbon atoms.

In molecules such as methane, the 8 valence electrons are in 4 MOs that are spread out over all 5 atoms. However, it is possible to transform this picture, without altering the total wavefunction and energy, to one with 8 electrons in 4 localized orbitals that are similar to the normal bonding picture of four two-electron covalent bonds. This is what has been done above for the σ (sigma) bonds of benzene, but it is not possible for the π (pi) orbitals. The delocalised picture is more appropriate for ionisation and spectroscopic properties. Upon ionization, a single electron is taken from the whole molecule. The resulting ion does not have one bond different from the other three Similarly for electronic excitations, the electron that is excited is found over the whole molecule and not in one bond.

As in benzene, in substances such as beta carotene, chlorophyll or heme, some electrons the π (pi) orbitals are spread out in molecular orbitals over long distances in a molecule, giving rise to light absorption in lower energies (visible colors), a fact which is observed. This and other spectroscopic data for molecules are better explained in MO theory, with an emphasis on electronic states associated with multicenter orbitals, including mixing of orbitals premised on principles of orbital symmetry matching. The same MO principles also more naturally explain some electrical phenomena, such as high electrical conductivity in the planar direction of the hexagonal atomic sheets that exist in graphite. In MO theory, "resonance" (a mixing and blending of VB bond states) is a natural consequence of symmetry. For example, in graphite, as in benzene, it is not necessary to invoke the sp2 hybridization and resonance of VB theory, in order to explain electrical conduction. Instead, MO theory simply recognizes that some electrons in the graphite atomic sheets are completely delocalized over arbitrary distances, and reside in very large molecular orbitals that cover an entire graphite sheet, and some electrons are thus as free to move and conduct electricity in the sheet plane, as if they resided in a metal.


text:
User talk:71.2.107.206

Welcome!
Welcome to Wikibooks, a collection of open-content textbooks! You don't have to log in to read or edit articles on Wikibooks, but creating an account is quick, free and non-intrusive, requires no personal information, and gives you many benefits, including:
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Νεοπτόλεμος ( talk | email | contribs ) 01:43, 25 March 2008 (UTC)

title: User talk:71.2.107.206


text: User talk:97.87.62.91

title: User talk:97.87.62.91


text:
Wikijunior:Famous Inventors/stub template

What was his or her childhood like?
 Did You Know?
 * First interesting fact.
 * Another interesting fact.
 * Yet another interesting fact.


text:
Muggles' Guide to Harry Potter/Magic/Quintaped

Overview
No one knows anything very much about the Quintaped, which is apparently mythological. Quintapeds inhabit the island of Drear, which, of course, is unplottable.

Extended Description
The story of the Quintapeds appears in Fantastic Beasts and Where to Find Them. "Newt Scamander" writes:

 * Legend has it that the Isle of Drear was once populated by two wizarding families, the McCliverts and the MacBoons. A drunken wizarding duel between Dugald, chief of the clan McClivert, and Quintius, head of the clan MacBoon, is supposed to have led to the death of Dugald. In retaliation, so the story has it, a gang of McCliverts surrounded the MacBoon dwellings one night and Transfigured each and every MacBoon into a monstrous five legged creature. The McCliverts realized too late that the transfigured MacBoon were infinitely more dangerous in this state (the MacBoons had the reputation for great ineptitude at magic). Moreover, the MacBoons resisted every attempt to change them back into human form. The monsters killed every last one of the McCliverts until no human remained on the island. It was only then that the MacBoon monsters realized that in the absence of anyone to wield a wand, they would be forced to remain as they were for evermore.

Analysis
Quintapeds do not enter into the principal story at any point; we must assume that their existence is intended as something of an extra-value cautionary tale only. Given the information about the difference between Transfiguration and the Animagus transform, we may wonder how much intelligence the Quintapeds retained from their days as MacBoons.


text: Muggles' Guide to Harry Potter/Magic/Ramora


text:
Muggles' Guide to Harry Potter/Magic/Re'em

Overview
The Re'em is a magical beast resembling a large ox with golden hide. Its blood gives the drinker immense strength for a limited time.


text:
Muggles' Guide to Harry Potter/Magic/Runespoor

Overview
The Runespoor is a magical three-headed snake, commonly 6-7 feet long with orange and black stripes, and native to Africa.

Extended Description
The Runespoor's eggs are produced through the mouth, the only magical creature to do so, and are viable for mental agility-enhancing potions.

According to some Parselmouths, the Runespoor's three heads each have a different personality. From someone facing the snake: The left head planned; deciding what the Runespoor was to do, the middle head dreamed; causing some Runespoors to stay dormant for days, lost in imagination, and the right head criticized; often hissing and judging the other two heads' actions. Due to this, many Runespoors are found with no right head, the other two heads having gotten tired of its criticism. As a consequence, most Runespoors do not live to an old age. The right head's fangs are quite venomous.


text:
Wikijunior:Famous Inventors/Early Inventors

Early Inventors
Contents

 * /Archimedes/
 * /Galileo/
 * /Antonie van Leeuwenhoek/


text:
User:Frogx~enwikibooks

hi!! java

title: User:Frogx~enwikibooks


text:
Operating System Design/Case Studies/QNX

The QNX Operating System is ideal for realtime applications. It provides multitasking, priority-driven preemptive scheduling, and fast context switching ‒ all essential ingredients of a realtime system.

QNX is also remarkably flexible. Developers can easily customize the operating system to meet the needs of their application. From a "bare-bones" configuration of a kernel with a few small modules to a full-blown network-wide system equipped to serve hundreds of users, QNX lets you set up your system to use only those resources you require to tackle the job at hand.

QNX achieves its unique degree of efficiency, modularity, and simplicity through two fundamental principles:

 * microkernel architecture
 * message-based interprocess communication

QNX's microkernel architecture
QNX consists of a small kernel in charge of a group of cooperating processes. The structure is more like a team than a hierarchy, as several players of equal rank interact with each other and with their "quarterback" kernel.

The QNX Microkernel coordinating the system managers.

The kernel is the heart of any operating system. In some systems the "kernel" comprises so many functions, that for all intents and purposes it is the entire operating system! But the QNX Microkernel is truly a kernel. First of all, like the kernel of a realtime executive, the QNX Microkernel is very small. Secondly, it's dedicated to only two essential functions:

 * Message passing : the Microkernel handles the routing of all messages among all processes throughout the entire system
 * Scheduling : the scheduler is a part of the Microkernel and is invoked whenever a process changes state as the result of a message or interrupt

Unlike processes, the Microkernel itself is never scheduled for execution. It is entered only as the direct result of kernel calls, either from a process or from a hardware interrupt.


text:
User talk:59.160.193.34

Join Us!
--Webaware talk 09:21, 25 March 2008 (UTC)

title: User talk:59.160.193.34


text: User:Manowi~enwikibooks

title: User:Manowi~enwikibooks


text:
User talk:Manowi~enwikibooks

Your account will be renamed
Hello,

The developer team at Wikimedia is making some changes to how accounts work, as part of our on-going efforts to provide new and better tools for our users like cross-wiki notifications. These changes will mean you have the same account name everywhere. This will let us give you new features that will help you edit and discuss better, and allow more flexible user permissions for tools. One of the side-effects of this is that user accounts will now have to be unique across all 900 Wikimedia wikis. See the announcement for more information.

Unfortunately, your account clashes with another account also called Manowi. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Manowi~enwikibooks that only you will have. If you like it, you don't have to do anything. If you do not like it, you can pick out a different name.

Your account will still work as before, and you will be credited for all your edits made so far, but you will have to use the new account name when you log in.

Sorry for the inconvenience.

Yours, Keegan Peterzell Community Liaison, Wikimedia Foundation 23:24, 17 March 2015 (UTC)

Renamed
 This account has been renamed as part of single-user login finalisation. If you own this account you can |log in using your previous username and password for more information. If you do not like this account's new name, you can choose your own using this form after logging in: . -- Keegan (WMF) (talk) 05:14, 19 April 2015 (UTC)

title: User talk:Manowi~enwikibooks


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User talk:217.199.54.130

Welcome!
Welcome to Wikibooks, a collection of open-content textbooks! You don't have to log in to read or edit articles on Wikibooks, but creating an account is quick, free and non-intrusive, requires no personal information, and gives you many benefits, including:
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We hope that you choose to become a Wikibookian and create an account. Feel free to ask me any questions you may have on my talk page. By the way, make sure to sign your posts and comments with four tildes (~~~~), which will let others know who left it.

Please use the discussion page for suggesting changes to pages. Thanks! Νεοπτόλεμος ( talk | email | contribs ) 09:51, 25 March 2008 (UTC)

title: User talk:217.199.54.130


text:
User talk:Eddie Segoura~enwikibooks

Your account will be renamed
Hello,

The developer team at Wikimedia is making some changes to how accounts work, as part of our on-going efforts to provide new and better tools for our users like cross-wiki notifications. These changes will mean you have the same account name everywhere. This will let us give you new features that will help you edit and discuss better, and allow more flexible user permissions for tools. One of the side-effects of this is that user accounts will now have to be unique across all 900 Wikimedia wikis. See the announcement for more information.

Unfortunately, your account clashes with another account also called Eddie Segoura. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Eddie Segoura~enwikibooks that only you will have. If you like it, you don't have to do anything. If you do not like it, you can pick out a different name.

Your account will still work as before, and you will be credited for all your edits made so far, but you will have to use the new account name when you log in.

Sorry for the inconvenience.

Yours, Keegan Peterzell Community Liaison, Wikimedia Foundation 23:07, 17 March 2015 (UTC)

Renamed
 This account has been renamed as part of single-user login finalisation. If you own this account you can |log in using your previous username and password for more information. If you do not like this account's new name, you can choose your own using this form after logging in: . -- Keegan (WMF) (talk) 04:55, 19 April 2015 (UTC)

title: User talk:Eddie Segoura~enwikibooks


text:
Robotics Kinematics and Dynamics/Serial Manipulator Differential Kinematics

Twists
A popular, and minimal way to represent the time derivate of a pose is a twist. A twist consists of two 3 × 1 vectors: $$\omega$$ and $$v$$, where $$\omega$$ is the angular velocity of the moving rigid body (manipulator link), and $$v$$ is the linear velocity of the point on the moving rigid body that instantaneously coincides with the origin of the reference frame.

$$t = \left( \begin{array}{c} \omega \\ v \end{array} \right)$$

Propagation of Velocity
Rotational velocities that are written with respect to the same frame can simply be added. Hence:

_{i + 1} \omega_{i + 1} = \, ^i _{i + 1} R \, _i \omega_i + \begin{pmatrix} 0 \\ 0 \\ \dot{\theta}_{i + 1} \end{pmatrix} $$

The linear velocity of the origin of a link is that of the origin of the preceeding link plus a rotational component:

_{i + 1} v_{i + 1} = \, ^i _{i + 1} R \left( _i v_i + _i \omega_i \times \, _i P_{i + 1} \right) $$

Note: In the above equations the resulting velocities are expressed relative to the frame of the current link. $$_i P_{i + 1}$$ is the vector pointing from the origin of frame $${i}$$ to that of frame $${i + 1}$$.

Example: The Two-Link Planar Manipulator
The link transformations that come with this manipulator can be easily derived graphically from looking at the figure on the right:

^1 _0 T = \begin{pmatrix} c_1 & -s_1 & 0 & 0 \\ s_1 & c_1 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \\ \end{pmatrix} $$

^2 _1 T = \begin{pmatrix} c_2 & -s_2 & 0 & l_1 \\ s_2 & c_2 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \\ \end{pmatrix} $$

^3 _2 T = \begin{pmatrix} 1 & 0 & 0 & l_2 \\ 0 & 1 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \\ \end{pmatrix} $$

Here, $$l_1$$ and $$l_2$$ are the lengths link 1 and 2, respectively.

Note: Notice again the use of $$s_i$$ and $$c_i$$ as shorthand notations for $$sin(\theta_i)$$ and $$cos(\theta_i)$$, respectively.

Hence, from the above equations:

_2 \omega_2 = \begin{pmatrix} 0 \\ 0 \\ \dot{\theta_1} + \dot{\theta_2} \end{pmatrix} $$ and:

_3 \omega_3 = _2 \omega_2 $$

Also:

_2 v_2 = \begin{pmatrix} c_2 & s_2 & 0 \\ -s_2 & c_2 & 0 \\ 0 & 0 & 1 \end{pmatrix} \left[ \begin{pmatrix} 0 \\ 0 \\ \dot{\theta_1} \end{pmatrix} \times \begin{pmatrix} l_1 \\ 0 \\ 0 \end{pmatrix} \right] = \begin{pmatrix} l_1 s_2 \dot{\theta_1} \\ l_1 c_2 \dot{\theta_1} \\ 0 \end{pmatrix} $$ and:

_3 v_3 = \begin{pmatrix} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{pmatrix} \left[ \begin{pmatrix} l_1 s_2 \dot{\theta_1} \\ l_1 c_2 \dot{\theta_2} \\ 0 \end{pmatrix} + \begin{pmatrix} 0 \\ 0 \\ \dot{\theta_1} + \dot{\theta_2} \end{pmatrix} \times \begin{pmatrix} l_2 \\ 0 \\ 0 \end{pmatrix} \right] = \begin{pmatrix} l_1 s_2 \dot{\theta_1} \\ l_1 c_2 \dot{\theta_2} + l_2 ( \dot{\theta_1} + \dot{\theta_2} ) \\ 0 \end{pmatrix} $$

With respect to the base frame, the end-effector velocity becomes:

_0 v_3 = \, _0 ^3 R \, _3 v_3 = \, _0 ^1 R \, _1 ^2 R \, _2 ^3 R \, _3 v_3 = \begin{pmatrix} -l_1 s_1 \dot{\theta_1} - l_2 s_{12} (\dot{\theta_1} + \dot{\theta_2}) \\ l_1 c_1 \dot{\theta_1} - l_2 c_{12} (\dot{\theta_1} + \dot{\theta_2}) \\ 0 \end{pmatrix} $$

Jacobian
Suppose $$m$$ kinematic (end-effector) equations. Each is a function of $$n$$ degrees of freedom:

\begin{array}{ccc} x_1 & = & x_1(\theta_1, \ldots, \theta_n) \\ \vdots & & \vdots \\ x_m & = & x_m(\theta_1, \ldots, \theta_n) \\ \end{array} $$

Note that in the case of a non-redundant manipulator, $$m = n$$.

The time derivate of the above equations is found as follows:

\begin{array}{ccc} \dfrac{dx_1}{dt} & = & \dfrac{\partial x_1}{\partial \theta_1} \dfrac{d \theta_1}{dt} + \cdots + \dfrac{\partial x_1}{\partial \theta_n} \dfrac{d \theta_n}{dt} \\ \vdots & & \vdots \\ \dfrac{dx_m}{dt} & = & \dfrac{\partial x_m}{\partial \theta_1} \dfrac{d \theta_1}{dt} + \cdots + \dfrac{\partial x_m}{\partial \theta_n} \dfrac{d \theta_n}{dt} \end{array} $$

This can be written in vector form:

v = J \frac{d \theta}{dt} $$

The matrix $$J$$ is called the Jacobian, the matrix of which the elements are the partial derivatives of the kinematics equations. The relationship between the end-effector velocity and the (known) joint velocities is thus fully described by the Jacobian. The end-effector velocity is a linear function of the joint velocities.

$$J = \begin{pmatrix} \frac{\partial x_1}{\partial \theta_1} & \cdots & \frac{\partial x_1}{\partial \theta_n} \\ \vdots & \ddots & \vdots \\ \frac{\partial x_m}{\partial \theta_1} & \cdots & \frac{\partial x_m}{\partial \theta_n} \end{pmatrix} $$

Example: The Two-Link Planar Manipulator
This example presents a slightly other way of solving the above problem. The position kinematics equations of this manipulator can be easily derived using the technique presented in the Serial Manipulator Position Kinematics section, or graphically from looking at the figure above:

\begin{array}{l} x = l_1 \cos(\theta_1) + l_2 \cos(\theta_1 + \theta_2) \\ y = l_1 \sin(\theta_1) + l_2 \sin(\theta_1 + \theta_2) \end{array} $$

Here, the Jacobian is:
 * $$J =

\begin{pmatrix} -l_1 \sin(\theta_1) - l_2 \sin(\theta_1 + \theta_2) & -l_2 \sin(\theta_1 + \theta_2) \\ l_1 \cos(\theta_1) + l_2 \cos(\theta_1 + \theta_2) & l_2 \cos(\theta_1 + \theta_2) \\ \end{pmatrix} $$

Hence, the end-effector velocity is:

\begin{array}{ccc} \dfrac{dx}{dt} & = & \left[ -l_1 \sin(\theta_1) - l_2 \sin(\theta_1 + \theta_2) \right] \dfrac{d \theta_1}{dt} - l_2 \sin(\theta_1 + \theta_2) \dfrac{d \theta_2}{dt} \\ \dfrac{dy}{dt} & = & \left[ l_1 \cos(\theta_1) + l_2 \cos(\theta_1 + \theta_2) \right] \dfrac{d \theta_1}{dt} + l_2 \cos(\theta_1 + \theta_2) \dfrac{d \theta_2}{dt} \\ \end{array} $$

Note that the end-effector's angular velocity is, of course, the sum of the joint velocities. Another possibility that yields exactly the same result would be to explicitly include the equation for angular velocity and then calculate the Jacobian accordingly. This result is, as could already be expected, the same as the one in the above example, where the link transformation matrices were used to achieve the result.

Inverse Velocity Kinematics
This problem can easily be solved by inverting the Jacobian...

Singularities
If the Jacobian $$J$$ is invertible, inverting it can be used to easily calculate the joint velocities if the (Cartesian) end-effector velocity is given. Locations (combinations of $$\theta_i$$ where the Jacobian is not invertible are called singularities. Setting the determinant of $$J$$ equal to zero and solving for $$\theta$$ allows for finding these singularities. These positions correspond to the loss of a degree of freedom.


text:
User talk:203.62.10.9

133.10.236.3 (talk) 11:35, 25 March 2008 (UTC)

title: User talk:203.62.10.9


text:
User:BrettR~enwikibooks

 * Name: Brett Reynolds
 * Education: M.Ed. in Teaching English as a Second or Other Language (TESOL).
 * Current position: Professor of English for Academic Purposes at Humber College
 * Blog: English, Jack
 * I am a bureaucrat on Simple English Wiktionary.

title: User:BrettR~enwikibooks


text:
SwisTrack/Components/DoubleThresholdColorIndependent

Description
This step intends to separate the pixels that belongs to tracked objects. The pixels kept are in white and the black pixels will be considered as the background. Most of the time, this step follows a preprocessing method like background subtraction. In this specific case, the output pixel is white if the three channel values of the input pixel is inside of the respective color boundaries. output= (Blue Low <= inputBlue <= Blue High) && (Green Low <= inputGreen <= Green High) && (Red Low <= inputRed <= Red High)

Input

A color image.

Output

A binary (black and white) image.

Blue Low
Lower boundary of the blue channel.

Blue High
Higher boundary of the blue channel.

Green Low
Lower boundary of the green channel.

Green High
Higher boundary of the green channel.

Red Low
Lower boundary of the red channel.

Red High
Higher boundary of the red channel.


text:
Template:German/Level III/Header

Lektion 1 | Lektion 2 | Lektion 3 | Lektion 4 | Lektion 5 | Lektion 6 | Lektion 7 | Lektion 8 | Lektion 9 | Lektion 10 | Lektion 11 | Lektion 12

title: Template:German/Level III/Header


text:
User:Whiteknight/Renaming and Usurpation

'''This page represents my rules only, and does not necessarily represent how other bureaucrats handle these issues. Wikibooks has no official policy about user renaming or username usurpation. If I cannot or will not help you, another bureaucrat might be willing or able to.'''

As a bureaucrat, I'm able to rename user accounts for people upon request. I'm also able, in some situations, to perform a usurpation. A usurpation is where we "steal" an existing account from one person to give to another person. Here on en.wikibooks there are no official policies concerning user renaming and usurpation, these are left up to the best discretion of the bureaucrats. However, to simplify the process and to answer some common questions, this page is going to serve as a bit of my "personal policy".

To start this whole rename process, you can send me a request to my user talk page, or you can post a request on the Administrator's Noticeboard.

Some rules concerning acceptable renames

 * Here at Wikibooks, we require that usernames must be appropriate. I will not change your user name to something with cursewords or offensive words.
 * I will not rename you to something that is similar to another person's username, with the intention to confuse people. I will not, for instance, rename you to "VVhiteknight" or something like that.
 * I will probably not rename you to a foreign word which I do not understand. I only speak English, so I will only handle rename requests for English usernames. I'm sorry in advance for this, but I cannot verify if a word written in another language is appropriate or not. If I can find a translator who is able to verify the appropriateness of your name, I will consider it. Other bureaucrats may be willing to perform requests like this, and if possible I will refer you to one of them.
 * I will not rename a person to a name which uses non-latin characters. If I make a typo in such a username I will probably not notice it and I may not be able to correct it. Again, I apologize for this, but I would rather not be making all sorts of uncorrectable mistakes with this tool. Other bureaucrats may be willing to do this, and I will refer you to them in that case.

SUL Concerns
Single User Login (SUL) is a software addition that is in the works, where user accounts on all WMF wikis are going to be combined. Because of SUL before performing a rename I may check to ensure that the account name you are requesting is not already taken at en.wikipedia. This is to prevent username collisions, or concerns over dopplegangers (people with the same name on different projects to cause problems).

If you are the same person on en.wikipedia or another wiki and you are requesting a rename here to match that username, I must see proof that you are the same person as that account. For more information about proof, see the section Proof That You Are The Same Person below.

What I need from you

 * You must have an email address registered with the software before I will rename you. Go to Special:Preferences and make sure that there is an email address entered there. This is so that if you lose your password information, that you can retrieve it. In the event of a problem, I can contact you via email to correct it.

Being Renamed
Once you have satisfied all the requirements above, I will rename you as requested. I will email you a confirmation once it is completed. The rename process automatically moves your user page and user talk page (and all subpages) to the new location. Do not create new pages in your new user space until I rename you. This complicates the process, and pages will need to get deleted.

Once you have been renamed, all your user settings are the same, and you have the same password. You may contact me at any time if you have questions about this.

Usurpable Usernames

 * The account to be usurped should satisfy the following conditions:
 * The account has few, if any edits, image uploads, or log entries.
 * The account has not been used recently (and I get do define "recently")
 * The account does not have a valid email address specified (if an email address is available, you should ask the user permission to usurp the username, or at least give fair warning).
 * If the account that you are usurping is permanently blocked due to vandalism or some other reason, I can usurp that account without question.

Before Usurpation, You Must:

 * Provide me with some way to contact you off-wiki. If you have an email address registered with your account, and if you set it so that you are able to receive mail from other users, I can use the Special:Emailuser page to contact you. Otherwise, you must provide me with an email address or a messenger chat ID, or you must contact me on IRC. When I usurp the account, I will send you the username and password information off-wiki.

Proof That You Are The Same Person
If you are a member of another wikimedia project and would like to have the same username here as well, you must:
 * 1) Edit that wiki with an edit summary that states that you are the same person.
 * 2) Post a diff link to this edit here on Wikibooks or through some other method so I can verify that you are the same person.

There may be other ways to verify your identity as well, although I doubt that any of them are easier then this. Contact me if you need to work out some other method (and have a good explanation ready for why you need it).


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A-level Physics (Advancing Physics)/Graphs

There are two types of graphs of motion you need to be able to use and understand: distance-time graphs and velocity-time graphs.

Distance-time Graphs
A distance-time graph plots the distance of an object away from a certain point, with time on the x-axis and distance on the y-axis.There are several types of graphs of motion you need to be able to use and understand: distance-time graphs, position-time graphs, and velocity-time graphs.

Position-time Graphs or Displacement - Time Graphs
Distance-Time Graphs give you speed, but speed is never negative so you can only have a positive slope in a distance-time graph. Position-Time graphs show displacement, have direction, and from which you can calculate velocity. If we were to imagine the line on the position-time graph to the right as a function f(t), giving an equation for s = f(t), we could differentiate this to gain:

$$\frac{ds}{dt} = f'(t)$$,

where s is displacement, and t is time. By finding f'(t) at any given time t, we can find the rate at which distance is increasing (or decreasing) with respect to t. This is the gradient of the line. A positive gradient means that distance is increasing, and a negative gradient means that distance is decreasing. A gradient of 0 means that the object is stationary. The velocity of the object is the rate of change of its displacement, which is the same as the gradient of the line on a distance-time graph. This is not necessarily the same as the average velocity of the object v:

$$v = \frac{s}{t}$$

Here, t and s are the total changes in displacement and time over a certain period - they do not tell you exactly what was happening at any given point in time.

Velocity-time Graphs
A velocity-time graph plots the velocity of an object, relative to a certain point, with time on the x-axis and velocity on the y-axis. We already know that velocity is the gradient (derivative) of the distance function. Since integration is the inverse process to differentiation, if we have a velocity-time graph and wish to know the distance travelled between two points in time, we can find the area under the graph between those two points in time. In general:

If $$v = f(t)\,$$

$$s = \int_{t_1}^{t_2} f(t)\, dt$$

where v is velocity (in ms−1), t is time (in s), and s is the distance travelled (in m) between two points in time t1 and t2.

Also, by differentiation, we know that the gradient (or derivative of v = f(t)) is equal to the acceleration of the object at any given point in time (in ms−2) since:

$$a = \frac{dv}{dt}$$

Questions
1. In the following distance-time graph, what is the velocity 4 seconds after the beginning of the object's journey?

2a)Describe this person's movements.

2b)What is the velocity at 12 seconds?

3. In the following velocity-time graph, how far does the object travel between 7 and 9 seconds?

4. What is the object's acceleration at 8 seconds?

5. A car travels at 10ms−1 for 5 minutes in a straight line, and then returns to its original location over the next 4 minutes, travelling at a constant velocity. Draw a distance-time graph showing the distance the car has travelled from its original location.

6. Draw the velocity-time graph for the above situation.

The following question is more difficult than anything you will be given, but have a go anyway:

7. The velocity of a ball is related to the time since it was thrown by the equation $$v = 30 - 9.8t\,$$. How far has the ball travelled after 2 seconds?

/Worked Solutions/


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User:Brett

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text:
A-level Physics (Advancing Physics)/Graphs/Worked Solutions

1. In the following distance-time graph, what is the velocity 4 seconds after the beginning of the object's journey?

At this point, the graph is a straight line. So:

$$v = \frac{ds}{dt} = \frac{10 - 0}{6 - 0} = \frac{5}{3} \approx 1.67\mbox{ms}^{-1}$$

2. What is the velocity at 12 seconds?

Approximately, there is a rough straight line at this point. The object is travelling towards home 2 ms−1 each second (look at the previous second, for example). So, its velocity is -2 ms−1.

3. In the following velocity-time graph, how far does the object travel between 7 and 9 seconds?

Distance travelled is equal to the area under the graph. Between 7 and 9 seconds, this is the shaded area of the graph. So, calculate the area of the triangle:

$$A = \frac{bh}{2} = \frac{2 \times 3}{2} = 3\mbox{m}$$

4. What is the object's acceleration at 8 seconds?

There is a straight line between 7 and 9 seconds which we can use to answer this question. The acceleration is equal to the gradient of the graph, so:

$$a = \frac{3}{2} = 1.5\mbox{ms}^{-2}$$

'''5. A car travels at 10ms−1 for 5 minutes in a straight line, and then returns to its original location over the next 4 minutes, travelling at a constant velocity. Draw a distance-time graph showing the distance the car has travelled from its original location.'''

10ms−1 = 600 metres / minute.

6. Draw the velocity-time graph for the above situation.

The velocity from 0-5s is 10ms−1. The velocity from 5-9s is:

$$v = \frac{3 \times 10^3}{4} = 750\mbox{ metres/minute} = 12.5\mbox{ms}^{-1}$$

'''7. The velocity of a ball is related to the time since it was thrown by the equation $$v = 30 - 9.8t\,$$. How far has the ball travelled after 2 seconds?'''

$$s = \int_{t_1}^{t_2} f(t)\, dt = \int_{0}^{2} 30 - 9.8t\, dt = [30t - 4.9t^2]_{0}^{2} = 30(2) - 4.9(2^2) - 30(0) + 4.9(0^2) = 60 - 19.6 = 40.4\mbox{ m}$$


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User:Fabexplosive

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User talk:Me2hero

Welcome!
Welcome, Me2hero!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally.-- – Mike.lifeguard  | talk 15:38, 25 March 2008 (UTC)

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User talk:Felisbelap

Welcome!
Welcome, Felisbelap!

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally.-- – Mike.lifeguard  | talk 15:38, 25 March 2008 (UTC)

title: User talk:Felisbelap