text:
Practical Electronics/IC/4000 Series

The 4000 series is a range of CMOS ICs introduced as a lower-power and more versatile alternative to the 7400 series in common use.

There are many ICs in the 4000 series, from simple logic gates to counters and many more.

ICs in the 4000 Series

 * 4000 - Dual 3-Input NOR Gate and Inverter
 * 4001 - Quad 2-Input NOR Gate
 * 4002 - Dual 4-Input NOR Gate
 * 4007 - Dual Complementary Pair and Inverter
 * 4008 - 4-Bit Full Adder
 * 4011 - Quad 2-Input NAND Gate
 * 4012 - Dual 4-input NAND Gate
 * 4013 - Dual D-type flip-flop with set and clear
 * 4014 - 8-bit Static Shift Register with Synchronous Parallel Enable Input
 * 4015 - Dual 4-Bit Serial-In/Parallel-Out Shift Register
 * 4016 - Quad Bilateral Switch
 * 4017 - Johnson Decade Counter with 10 Decoded Outputs
 * 4020 - 14-stage binary counter
 * 4021 - 8-Bit Static Shift Register with Asynchronous Parallel Load Input
 * 4022 - 4-Bit binary up/down counter
 * 4023 - triple 3-input NAND gate
 * 4024 - 7-Stage Binary Ripple Counter
 * 4025 - Triple 3-Input NOR Gate
 * 4026 - Decade counter with seven-segment display driver
 * 4027 - Dual J-K flip-flop with set and clear
 * 4028 - 1-of-10 Decoder
 * 4029 - Synchronous Up/Down Counter, Binary/Decade Counter
 * 4030 - Quad 2-input XOR gate (obsoleted by 4070)
 * 4038 - Dual monostable timer
 * 4040 - 12-Stage Binary Counter
 * 4041 - Buffer; True Complement
 * 4043 - Quad R/S Latch with Active HIGH Set and Reset Inputs (3-State)
 * 4043 - Quad Tri-state Set/Reset latch
 * 4044 - Quad R/S Latch with Active LOW Set and Reset Inputs (3-State)
 * 4046 - PLL with VCO
 * 4047 - Monostable/Astable Multivibrator
 * 4049 - Buffer; Inverting (6 NOT gates) (unusual pin configuration, capable of directly driving 74-series TTL)
 * 4050 - Buffer; Non-Inverting (6 buffers) (unusual pin configuration, capable of directly driving 74-series TTL)
 * 4051 - 8-Channel Analog Multiplexer/Demultiplexer
 * 4052 - Dual 4-Channel Analog Multiplexer/Demultiplexer
 * 4053 - Triple 2-Channel Analog Multiplexer/Demultiplexer
 * 4054 - Seven-segment display decoder/LCD driver
 * 4059 - Programmable Divide-By-N Counter
 * 4060 - 14-Stage Ripple-Carry Binary Counter/Divider and Oscillator
 * 4063 - 4-Bit magnitude comparator
 * 4066 - Quad Analogue Switch (Low "ON" Resistance)
 * 4067 - 16-Channel Analog Multiplexer/Demultiplexer
 * 4068 - 8-input NAND/AND gate
 * 4069 - Hex Inverter (6 unbuffered NOT gates)
 * 4070 - Quad EXCLUSIVE-OR Gate
 * 4071 - Quad 2-Input OR Gate
 * 4072 - Dual 4-Input OR Gate
 * 4073 - Triple 3-Input AND Gate
 * 4075 - Triple 3-Input OR Gate
 * 4076 - Quad D-Type Register with 3-State Outputs
 * 4077 - Quad EXCLUSIVE-NOR Gate
 * 4081 - Quad 2-Input AND Gate
 * 4082 - Dual 4-Input AND Gate
 * 4093 - Quad 2-Input NAND Schmitt-Trigger
 * 4094 - 8-Stage Shift-and-Store Bus Register
 * 4098 - Dual Monostable Multivibrator; Retriggerable
 * 4104 - Quad Low-to-High Voltage Translator with 3-State Outputs
 * 4502 - Strobed Hex Inverter/Buffer (3-State)
 * 4511 - BCD to seven-Segment Latch/Decoder/Driver with Lamp Test Input
 * 4512 - 8-Input Multiplexer (3-State)
 * 4514 - 1-of-16 Decoder/Demultiplexer with Input Latches; Outputs LOW at Data Input HIGH
 * 4515 - 1-of-16 Decoder/Demultiplexer with Input Latches; Outputs HIGH at Data Input HIGH; Inverting
 * 4516 - Binary Up/Down Counter
 * 4517 - Dual 64-Bit Static Shift Register
 * 4518 - Dual BCD Counter
 * 4519 - Quad 2-Input Multiplexer
 * 4520 - Dual 4-Bit Synchronous Binary Counter
 * 4521 - 24-Stage Frequency Divider and Oscillator
 * 4526 - Programmable 4-Bit Binary Down Counter
 * 4528 - Dual Retriggerable Monostable Multivibrator with Reset
 * 4532 - 8-Input Priority Encoder
 * 4538 - Dual Retriggerable Precision Monostable Multivibrator
 * 4541 - Programmable Timer
 * 4543 - BCD to 7-Segment Latch/Decoder/Driver with Phase Input
 * 4555 - Dual 1-to-4 Line Decoder/Demultiplexer
 * 4556 - Dual 1-of-4 Decoder/Demultiplexer
 * 4557 - 1-to-64 Bit Variable Length Shift Register
 * 4585 - 4-Bit Magnitude Comparator
 * 4750 - Frequency Synthesizer
 * 4751 - Universal Divider
 * 4794 - 8-Stage Shift-and-Store Register LED Driver
 * 4894 - 12-Stage Shift-and-Store Register LED Driver
 * 4938 - Dual Retriggerable Precision Monostable Multivibrator with Reset
 * 4952 - 8-channel analog multiplexer/demultiplexer
 * 40098 - Hex Inverting Buffer (3-State)
 * 40105 - 4 bit x 16 word fifo register
 * 40106 - Hex Inverting Schmitt-Trigger
 * 40106 - hex Schmitt trigger inverter (NOT gates)
 * 40174 - Hex D-type flip-flop with reset; positive-edge trigger
 * 40175 - Quad D-type flip-flop with reset; positive-edge trigger
 * 40193 - 4-Bit Up/Down Binary Counter
 * 40240 - Buffer/Line Driver; Inverting (3-State)
 * 40244 - Buffer/Line Driver; Non-Inverting (3-State)
 * 40373 - Octal D-Type Transparent Latch (3-State)
 * 40374 - Octal D-type flip-flop; positive-edge trigger (3-state)

title: Practical Electronics/IC/4000 Series


text:
Horticulture/Garden Tools

Tools and equipment used by gardeners.

Digging

 * ../Spades/
 * ../Shovels/
 * ../Mattocks/
 * Digging bars

Cultivation

 * ../Stirrup Hoes/
 * ../Hand Cultivators/

Pruning

 * Garden scissors
 * ../Pruners
 * Bypass pruners
 * ../Shears/
 * ../Loppers/
 * Bypass loppers
 * ../Saws/
 * ../Pole-clips/
 * ../Pole-saws/

Chemical delivery

 * ../Sprayers/
 * ../Dusters/
 * ../Spreaders/
 * ../Needles/

Moving things around

 * ../Wheelbarrows/
 * ../Dolly-carts/

Pots

 * Plastic pots
 * Ceramic pots
 * Peat/Coir Pots

Cells

 * ../CP-72/
 * ../CP-36/
 * ../CP-24/

Power tools

 * ../Chainsaws/
 * ../Blowers/
 * Lawn mowers
 * ../Tractors/
 * Chippers
 * ../Power sprayers/
 * ../Tillers/
 * Root grinders

/Tools

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

title: Horticulture/Garden Tools


text:
User:Alfred Heiligenbrunner

Hi, I am Alfred from Austria.

Alfred Heiligenbrunner 18:25, 5 August 2006 (UTC)

title: User:Alfred Heiligenbrunner


text:
Talk:Puzzles/Geometric Puzzles/Rubber Band/Solution 1

I doubt, this is a correct solution. (Maybe I did not get it right.) I cannot construct a triangle with lengths 1.5, 2 and 6. (Try it!) I'd rather suggest to build a triangle with lengths 1.5, 2 and 2.5. Or, even better, 3, 4 and 5. Alfred Heiligenbrunner 18:29, 5 August 2006 (UTC)


text:
Puzzles/Geometric Puzzles/Rubber Band/Solution 2

Puzzles | Geometric puzzles | Rubber Band | Solution 2

1. By stretching the rubber band, while holding the loose end to the nail, you can measure 4 cm. Draw a circle with radius 4cm around the nail.

2. Unstretch the rubber band and, while holding the loose end to the nail, draw a circle with radius 3 cm around the nail.

3. Stretch the rubber band. (It's 8 cm long now.) At the point, where it crosses the 3cm-line, fix it with your left-hand finger. The rest of the rubber band is 5 cm long. Turn the 5cm-part, so that the free end lies on the 4cm-line from step 1. Put your right-hand finger there.

The triangle "left finger" - "nail" - "right finger" has lengths 3, 4 and 5. Therefore it is a right-angled triangle.


text:
User talk:D.E. Wittkower

I've just started a textbook: Political Philosophy: Ancient to Renaissance. Comments are welcome.

It should be done in December.

Philosophy Book
Hi. It seems like you already know what you're doing on WP. I'll offer a belated welcome nonetheless.

Anyway, Re:Your comment on User talk:Alex beta, the philosophy department has moved from wikibooks's wikiversity (which was only ever intended as an incubator for wikiversity), to Wikiversity proper. The new head of department there is Koavf. If you message an admin on wikiversity, he will transfer the work you have done here on to wikiversity proper (preserving the history etc.).

Keep up the good work. --Cfp 11:58, 21 August 2006 (UTC)

title: User talk:D.E. Wittkower


text:
User:Collinj

w:de:Benutzer:Collinj

title: User:Collinj


text:
Life in the Open Ocean/Webquests/WebQuest Plankton

Introduction
This is an example sdsfdsdsdsfds

The Task
Describe crisply and clearly what the end result of the learners' activities will be. The task could be a: If the final product involves using some tool mention it here. Remember to link to all appropriate words in Wikipedia with the prefix w: Example: plankton
 * problem or mystery to be solved;
 * position to be formulated and defended;
 * product to be designed;
 * complexity to be analyzed;
 * personal insight to be articulated;
 * summary to be created;
 * persuasive message or journalistic account to be crafted;
 * a creative work, or anything that requires the learners to process and transform the information they've gathered.

The Process
To accomplish the task, what steps should the learners go through? Remember that this is addressed to the student so describe the steps using the second person. Learners will access the on-line resources that you've identified as they go through the Process. You may have a set of links that everyone looks at as a way of developing background information, or not. If you break learners into groups, embed the links that each group will look at within the description of that stage of the process.
 * 1) First you'll be assigned to a team of 3 students...
 * 2) Once you've picked a role to play....
 * 3) ... and so on.

In the Process block, you might also provide some guidance on how to organize the information gathered. This advice could suggestions to use flowcharts, summary tables, concept maps, or other organizing structures. The advice could also take the form of a checklist of questions to analyze the information with, or things to notice or think about.

Evaluation
Describe to the learners how their performance will be evaluated. Specify whether there will be a common grade for group work vs. individual grades.

Conclusion
Put a couple of sentences here that summarize what they will have accomplished or learned by completing this activity or lesson. You might also include some rhetorical questions or additional links to encourage them to extend their thinking into other content beyond this lesson.

Credits & References
List here the sources of any images, music or text that you're using. Provide links back to the original source. Say thanks to anyone who provided resources or help. List any books and other analog media that you used as information sources as well.

Authors
Put here name and other information about designers and authors of this webquest.

Based on a template from The WebQuest Page

>>>𝚘𝚗𝚎 𝚘𝚏 𝚝𝚑𝚎 𝚊𝚞𝚝𝚑𝚘𝚛𝚜 𝚝𝚘 𝚋𝚎 𝚊𝚌𝚔𝚗𝚘𝚠𝚕𝚎𝚐𝚍𝚎𝚍 𝚒𝚗 𝚝𝚑𝚒𝚜 𝚙𝚑𝚛𝚊𝚜𝚎 𝚒𝚗𝚌𝚕𝚞𝚍𝚎: 𝙼𝚛 𝙳𝚕𝚘𝚍𝚕𝚘 𝙼𝚛 𝚞𝚜𝚍𝚏𝚍𝚏 𝙰𝚗𝚍 𝙸𝚙 𝚖𝚊𝚗


text:
Nature/Definition

Back to Nature

What is nature? = Science wants to understand nature. Therefore it is important, how the word nature is defined: Nature is everything that was not made by man. So the definition of nature excludes all things that where introduced by mankind. All those human developments are summarized as culture. The definition of nature summarizes natural objects, e.g. It also reflects on events in nature like Nature can be divided in a living and a not living (abiotic) part.
 * stones
 * animals
 * plants
 * the wind
 * the rain
 * earthquakes
 * food

Living nature
The living part of nature consist of all life on earth.
 * plants
 * animals
 * mushrooms
 * bacteria
 * humans

Abiotic nature
The abiotic part of nature consist of all things, that were not made by man and are not living. You can count to it: See also http://en.wikipedia.org/wiki/Goethite
 * the outer space
 * not living objects on earth (stones, water, air etc)

=Natural philosophy=

The so called natural philosophy of former centuries had a somewhat different meaning as science today. Sie beschäftigte sich mit dem Wesen aller Dinge und wie der Mensch Erkenntnis darüber gewinnt. Sie wurde teilweise von den Naturwissenschaften abgelöst.

=Citations=

 * "Adapt or perish, now as ever, is Nature's inexorable imperative." - H.G. Wells (1866-1946), Mind at the End of Its Tether, 1945

 * "All nature wears one universal grin." - Henry Fielding (1707-1754), 'Tom Thumb the Great'', 1730.

 * "Climb the mountains and get their good tidings. Nature's peace will flow into you as sunshine flows into trees.  The winds will blow their own freshness into you, and the storms their energy, while cares will drop off like autumn leaves." –-John Muir (1838-1914)

 * "Come forth into the light of things, Let Nature be your teacher." - William Wordsworth (1770-1850), The Tables Turned, 1798

 * "Fortunately science, like that nature to which it belongs, is neither limited by time nor by space. It belongs to the world, and is of no country and no age.  The more we know, the more we feel our ignorance; the more we feel how much remains unknown." –-Humphry Davy (1778-1829), 30.11.1825

 * "How Strange that Nature does not knock, and yet does not intrude!" - Emily Dickinson, (1830-1886), Letter to Mrs. J.S. Cooper.

 * "I am not insensible to natural beauty, but my emotional joys center on the improbable yet sometimes wondrous works of that tiny and accidental evolutionary twig called Homo sapiens. And I find, among these works, nothing more noble than the history of our struggle to understand nature -– a majestic entity of such vast spatial and temporal scope that she cannot care much for a little mammalian afterthought with a curious evolutionary invention, even if that invention has, for the first time in some four billion years of life on earth, produced recursion as a creature reflects back upon its own production and evolution.  Thus, I love nature primarily for the puzzles and intellectual delights that she offers to the first organ capable of such curious contemplation." ~Stephen Jay Gould (1941-2002), Prologue (In: Bully for Brontosaurus), 1991

 * "In all things of nature there is something of the marvelous." - Aristotle (B.C. 384–322)

 * "In the landscape of spring, there is neither better nor worse. The flowering branches grow naturally, some long, some short." --Zen saying

 * "It is in man's heart that the life of nature's spectacle exists; to see it, one must feel it." - Jean-Jacques Rousseau (1712-1778), Emile, 1762

 * "Laws Change; people die; the land remains." - Abraham Lincoln (1809-1865), quoted in Peter Blake's God's Own Junkyard, 1964

 * "Look abroad through Nature's range,
 * Nature's mighty law is change." –-Robert Burns (1759-1796), Let not woman e'er complain, 1794

 * "Mountains are earth's undecaying monuments." - Nathaniel Hawthorne (1804-1864), The Notch of the White Mountains, 1868.

 * Naturam expellas furca, tamen usque revenit.
 * You can drive nature out with a pitchfork, she will nevertheless come back.
 * Horace (65-8 BC), Epistles I.X.24

 * "Nature answers only when she is questioned." --Jacob Henle (1809-1885)

 * "Nature, even when she is scant and thin outwardly, satisfies us still by the assurance of a certain generosity at the roots." - Henry David Thoreau (1817-1862) A Week on the Concord and Merrimack Rivers, 1849

 * "Nature is painting for us, day after day, pictures of infinite beauty." - John Ruskin, (1819-1900)

 * "Nature never did betray
 * The Heart that Loved her."
 * - William Wordsworth, (1770-1850), Lines Composed a Few Miles Above Tintern Abbey 1798.

 * "Nature provides exceptions to every rule." - Margaret Fuller, The Dial, July 1843.

 * "Nothing is rich but the inexhaustible wealth of nature. She shows us only surfaces, but she is a million fathoms deep." –-Ralph Waldo Emerson (1803-1882)

 * "Nature provides a free lunch, but only if we control our appetites." - William Ruckelshaus, first EPA Administrator, (1970-1973 and 1983-1985), Business Week, June 18, 1990.

 * "Nature teaches more than she preaches. There are no sermons in stones.  It is easier to get a spark out of a stone than a moral." –-John Burroughs (1837-1921)

 * "One Touch of nature makes the whole world kin." - William Shakespeare (1564-1616), Troilus and Cressida

 * "Perhaps I am just a hopeless rationalist, but isn't fascination as comforting as solace? Isn't nature immeasurably more interesting for its complexities and its lack of conformity to our hopes?  Isn't curiosity as wondrously and fundamentally human as compassion?" –-Stephen Jay Gould (1941-2002), Tires to sandals (In: Eight little piggies), 1993

 * Calvin: "That's the problem with nature. Something's always stinging you or oozing mucus on you.  Let's go watch TV." –-Bill Watterson, Something under the bed is drooling, 1988

 * "The belief that we can manage the Earth and improve on Nature is probably the ultimate expression of human conceit, but it has deep roots in the past and is almost universal." - Rene J. Dubos, (1901-1982), The Wooing of the Earth, 1980.

 * "The famous balance of nature is the most extraordinary of all cybernetic systems. Left to itself, it is always self-regulated." - Joseph Wood Krutch (1893-1970), Saturday Review, June 8, 1963

 * "The moment one give close attention to anything, even a blade of grass, it becomes a mysterious, awesome, indescribably magnificent world in itself." --Henry Miller

 * "The tree which moves some to tears of joy is in the eyes of others only a green thing that stands in the way. Some see nature all ridicule and deformity ... and some scarce see nature at all.  But to the eyes of the man of imagination, nature is imagination itself." –-William Blake (1757-1827)

 * "The true beauty of nature is her amplitude; she exists neither for nor because of us, and possesses a staying power that all our nuclear arsenals cannot threaten (much as we can easily destroy our puny selves)." –-Stephen Jay Gould (1941-2002), Prologue (In: Bully for Brontosaurus), 1991

 * "The Wilderness and the idea of wilderness is one of the permanent homes of the human spirit." - Joseph Wood Krutch (1893-1970), Today and All Its Yesterdays, 1958.

 * "To be whole. To be complete. Wildness reminds us what it means to be human, what we are connected to rather than what we are separate from." - Terry Tempest Williams, testimony before the Senate Subcommittee on Forest & Public Lands Management regarding the Utah Public Lands Management Act of 1995. Washington, D.C. July 13, 1995.

 * "Until man duplicates a blade of grass, nature can laugh at his so-called scientific knowledge." - Thomas Edison

 * "We cannot command nature except by obeying her." –-Francis Bacon (1561-1626)

 * "We do not inherit the earth from our ancestors, we borrow it from our children." --Navajo Proverb

 * "What is life? It is the flash of a firefly in the night.  It is the breath of a buffalo in the wintertime.  It is the little shadow which runs across the grass and loses itself in the sunset." --Crowfoot, Native American warrior and orator (1821-1890)

 * "When one tugs at a single thing in nature, he finds it attached to the rest of the world." –-John Muir (1838-1914)

 * "Whoever you are, no matter how lonely, the world offers itself to your imagination, calls to you like the wild geese, harsh and exciting -- over and over announcing your place in the family of things." ~Mary Oliver

 * "Wilderness is not a luxury but a necessity of the human spirit." - Edward Abbey (1927-1989)

 * ''Is your cucumber bitter? Throw it away. Are there briars in your path? Turn aside. That is enough. Do not go on and say, "Why were things of this sort ever brought into this world?" neither intolerable nor everlasting - if thou bearest in mind that it has its limits, and if thou addest nothing to it in imagination. Pain is either an evil to the body (then let the body say what it thinks of it!)-or to the soul. But it is in the power of the soul to maintain its own serenity and tranquility. . .”
 * Marcus Aurelius

=german=

 * Natur, adjective (formaliter) genommen, bedeutet den Zusammenhang der Bestimmungen eines Dinges nach einem innern Princip der Causalität. Dagegen versteht man unter Natur substantive (materialiter) den Inbegriff der Erscheinungen, so fern diese vermöge eines innern Princips der Causalität durchgängig zusammenhängen. Im ersteren Verstande spricht man von der Natur der flüssigen Materie, des Feuers etc. und bedient sich dieses Worts nur adjective; dagegen wenn man von den Dingen der Natur redet, so hat man ein bestehendes Ganzes in Gedanken.
 * Immanuel Kant

 * Die Natur verhält sich seltsam. Sie lebt gefährlich. Aber sie tänzelt so geschickt herum, dass sie dem fatalen K.o.-Schlag eines logischen Paradoxons auszuweichen vermag.
 * Brian Greene

 * "Alle Auflehnung gegen die Natur, gegen die Seinsbedingungen ist unfruchtbar und krankhaft." - Sully Prudhomme, Intimes Tagebuch

 * "Alles, was gegen die Natur ist, hat auf die Dauer keinen Bestand." - Charles Darwin
 * "Auf einem Berge stehend umfassen wir die Natur wie das Kind, das auf einen Stuhl gestiegen ist, um den Vater desto besser umarmen zu können." - Karl Julius Weber, Demokritos III
 * "Blumen sind die Liebesgedanken der Natur." - Bettina von Arnim
 * "Das Buch der Natur ist mit mathematischen Symbolen geschrieben." - Galileo Galilei
 * "Denn wahrhaftig steckt die Kunst in der Natur, wer sie heraus kann reißen, der hat sie." - Albrecht Dürer, Vier Bücher von menschlicher Proportion
 * "Der Mensch - ein Exempel der beispiellosen Geduld der Natur." - Christian Morgenstern
 * "Der Mensch kann die Natur nicht erreichen, nur übertreffen; er ist entweder über ihr oder unter ihr." - Christian Friedrich Hebbel
 * "Die größte Unbescheidenheit ist der Anspruch auf Unsterblichkeit, die Zumutung an die Natur, diese dürftige Menschenkreatur selbst in den misslungensten Exemplaren für Ewigkeiten aufzubewahren." - Heinrich Leuthold, Sprüche 2
 * "Die Natur ist groß. Sie erzeugt, aber kennt keine Kinder; sie vollendet, aber kennt keinen Besitz." - Lü Bu We
 * "Die Natur macht keine Sprünge, heißt es. Und die Kinder: Sind sie etwa keine Natur?" - Gregor Brand
 * "Die Natur übt ein heimlicheres Gericht; leise und langmütig, aber unentrinnbar." - Ernst von Feuchtersleben
 * "Der Natur liegt bloß unser Dasein, nicht unser Wohlsein am Herzen." - Arthur Schopenhauer
 * "Die Natur, die weniger stiefmütterlich ist, als ihre Verleumder sie schildern, legt oft in ihre Kargheit selbst den Sporn, der neue Anstrengung hervorruft und die Geistesanlagen entwickelt." - Georg Forster, Über die Beziehung der Staatskunst auf das Glück der Menschheit
 * "Der wirksamste Schutz der Natur ist die Hinfälligkeit des Menschen, seiner Werke und seiner Handlungen, deren Auswirkungen ihn früher oder später selbst vernichten müssen, weil ein Großteil seiner heutigen Handlungen allem Natursinn entgegen gerichtet ist." - Viktor Schauberger
 * "Die Folianten vergilben, der Städte gelehrter Glanz erbleicht, aber das Buch der Natur erhält jedes Jahr eine neue Auflage." - Hans Christian Andersen
 * "Die Konsequenz der Natur tröstet schön über die Inkonsequenz der Menschen." - Johann Wolfgang von Goethe, Brief an Karl Ludwig von Knebel, 2. April 1785
 * "Die Natur ist das einzige Buch, das auf allen Blättern großen Gehalt bietet." - Johann Wolfgang von Goethe
 * "Die Natur ist unerbittlich und unveränderlich, und es ist ihr gleichgültig, ob die verborgenen Gründe und Arten ihres Handelns dem Menschen verständlich sind oder nicht." - Galileo Galilei
 * "Die Mathematik ist das, womit die Menschen die Natur und sich selbst steuern." - Andrej Kolmogorow
 * "Die Natur weicht der Hacke, aber sie kehrt zurück." - Horaz
 * "Die Natur widersetzt sich allem Übermaß." - Hippokrates
 * "Einen Lehrer gibt es, wenn wir ihn verstehen; es ist die Natur." - Heinrich von Kleist
 * "Es geht nichts über die Freude, die uns das Studium der Natur gewährt. Ihre Geheimnisse sind von unergründlicher Tiefe, aber es ist uns Menschen erlaubt und gegeben, immer weitere Eingriffe hinein zu tun. Und gerade, dass sie am Ende doch unergründlich bleibt, hat für uns einen ewigen Reiz, immer wieder zu ihr heranzugehen und immer wieder neue Einblicke und neue Entdeckungen zu versuchen." - Johann Wolfgang von Goethe
 * "Ich sehe die Natur als etwas Leidenschaftliches, Stürmisches, Unheimliches und Dramatisches an wie mein eigenes Ich." - Pablo Picasso
 * "Im christlich-abendländischen Denken besitzt die Natur nur dann einen Wert, wenn sie in irgendeiner Weise genutzt werden kann." - Unbekannter Autor
 * "Jedes Naturgesetz, das sich dem Beobachter offenbart, lässt auf ein höheres, noch unerkanntes schließen." - Alexander von Humboldt
 * "Macht euch vertraut mit Natur, erkennt sie als eure Mutter; ruhig sinket ihr dann in die Erde hinab." - Anselm Feuerbach, Satirisch-theologische Distichen
 * "Man kann nicht gegen die Natur angehen. Sie ist stärker als der stärkste Mann. Es liegt nur in unserem eigensten Interesse, wenn wir uns gut mit ihr stellen." - Pablo Picasso
 * "Man muss sich gegenseitig helfen, das ist ein Naturgesetz." - Jean de La Fontaine, Fabeln
 * "Natur in der Form wilder Landschaft ist der beste Spiegel unserer Seele." - Reinhold Messner
 * "Stärker als alle Grundsätze ist die Natur." - David Hume, Eine Untersuchung in Betreff des menschlichen Verstandes, 12, 2, 7. Absatz
 * "Und wenn du noch so oft an ihre Türen klopfst, die Natur wird nie erschöpfend Auskunft geben." - Iwan S. Turgenjew, Aufzeichnungen eines Jägers
 * "Unkraut ist die Opposition der Natur gegen die Regierung der Gärtner." - Oskar Kokoschka
 * "Wenn der Frühling ins Land zieht, wäre es eine Beleidigung der Natur, nicht einzustimmen in ihr Jauchzen." - John Milton
 * "Wer das Alphabet erschaffen hat, hat uns den Faden unserer Gedanken und den Schlüssel der Natur in die Hand gegeben." - Antoine de Rivarol, Maximen und Reflexionen
 * "Wie viel ich Täuschung auch erfuhr im Leben und im Lieben, du bist mir allezeit, Natur, du bist mir treu geblieben." - Emanuel Geibel, Lieder aus alter und neuer Zeit 25
 * "Wir können die Natur nur dadurch beherrschen, dass wir uns ihren Gesetzen unterwerfen." - Francis Bacon

=Links=
 * http://en.wikipedia.org/wiki/nature
 * http://en.wikipedia.org/wiki/Natural_philosophy
 * http://caliban.mpiz-koeln.mpg.de/~stueber/haeckel/kunstformen/natur.html

title: Nature/Definition


text:
Practical Electronics/Adders

An adder is a device that will add together two bits and give the result as the output. The bits being added together are called the "addends". Adders can be concatenated in order to add together two binary numbers of an arbitrary length.

There are two kinds of adders - half adders and full adders. A half adder just adds two bits together and gives a two-bit output. A full adder adds two inputs and a carried input from another adder, and also gives a two-bit output.

Half Adders
When adding two separate bits together there are four possible combinations. Each of these is shown in the left with its solution.

It can easily be seen that the bit in the right-hand column (the "ones" column) is a 1 only when the addends are different. XORing the addends together can therefore give us the right-hand bit. This bit is called the sum and is the modulo-2 sum of the addends (i.e. the solution if you loop round to zero again once you pass one).

The left-hand bit reads 1 only when both addends are 1, so an AND gate can be used to generate this bit, called the carried bit. As a summary:

 * $$S =A \oplus B \,$$
 * $$C=A B \,$$

The diagram to the left shows the complete half adder with the addends being represented by A and B, the sum represented by S and the carried bit represented by C.

The truth table is as follows (the number in the brackets are the weights of the bits - each addend is one, as is the sum - the carried bit is two)

Full Adders
The downfall of half adders is that while they can generate a carry out output, they cannot deal with a carry in signal. This means that they can only ever be stand-alone units, and cated to add multiple bit numbers.

A full adder solves this problem by adding three numbers together - the two addends as in the half adder, and a carry in input.

A full adder can be constructed from two half adders by connecting A and B to the input of one half adder, connecting the sum from that to an input to the second adder, connecting the carry in, Cin, to the other input and ORing the two half adder carry outputs to give the final carry output, Cout.

The diagram below shows a full adder at the gate level.

A version of this diagram showing the two half adder modules outlined is available here. The output of the full adder is the two-bit arithmetic sum of three one-bit numbers.

The logic expressions for this full adder are:

 * $$S = \left( A \oplus B\right) \oplus C_{in} \,$$
 * $$C_{out} = \left( AB \right) + \left( C_{in}\left( A \oplus B \right) \right)\,$$

By applications of boolean algebra, the second statement simplifies to

 * $$C_{out} = \left( AB \right) + \left( BC_{in} \right) + \left( AC_{in} \right) \,$$

Giving the inputs in a three digit number where the first is the state of A, the second the state of B and the third the state of Cin, below is a description of the function of this full adder:

 * All combinations resultings in one (100, 010, 001) produce a high at the sum output, as the presence of only one high at the second XOR gate (the first gate gives a low when A and B are low and a high when either A or B is high) gives a high output at the sum output. The fact that only one input is ever high prevents either AND gate from going high and give a high Cout.

 * All combinations resulting in two (011, 101, 110) produce a high carry out and a low sum:

 * 011 sends the first XOR gate high as A and B are different. Combined with the high at Cin, this sends the top AND gate high and therefore the carry output high as well. The presence of two highs at the second XOR gate hold the sum low.

 * 101 works in exactly the same way as 011, as A and B are interchangeable.

 * 110: The high A and B force the first XOR low; this low, combined with the low from Cin gives a low at the sum. The highs at A and B send the lower AND gate high and therefore Cout is high.

 * When the inputs are 111, the first XOR gate is low due to the two high inputs, and the second XOR gate goes high, as it has one low input (from the first XOR gate) and one high input (from the Cin input). This gives a high sum output. The fact that both A and B are high triggers the lower AND gate, and the Cout output goes high as well.

The truth table for a full adder is given below with the weights of the inputs and outputs:

If A and B are both high then the AND gate connected to them gives a high output, but the XOR gate gives a low, forcing the other AND gate low. If the "sum" output of the first half adder is high, then one of A or B must be low, meaning that the AND gate connected to them is force low. This means that two inputs to the OR gate combining the half adder carry outs can never both be high, this gate can be replaced with an XOR gate (OR and XOR differ only when both inputs are high). This means that only two kinds of gates are needed, and a full adder can be realised with only two ICs.

These can be run in stages, with the carry out of one stage driving the carry in of the next. This is discussed in the next section.

Multiple-bit Addition
In the previous section we said how we could add two one-bit binary numbers, taking into account any carried digits from the previous binary order of magnitude (BOOM) and any digits carried to the next BOOM. By concatenating (stringing together) these one-bit adders, we can make an adder to add an arbitrary length binary number.

To do this, connect the carry in of the first stage to ground, as no bits are carried in from before the least significant bit. Then connect the carry out of the first stage to the carry in of the next, and so on for as many stages as you like.

Below is the layout for a 4-bit adder:

Bear in mind that the result will only be complete when the carry output have registered in each of the stages in turn. This ripple effect is why this kind of adder is called a ripple carry adder. This takes a small amount of time, and for large (32-bit or more) adders it may take several hundred nanoseconds, which may be a problem if high speed is needed.

There are much faster adders that can be made that don't have a ripple effect, such as carry lookahead adders.

IC Implementation
The 4008 IC is a 4-bit full adder, which can in turn be concatenated with others to provide any length of number.

title: Practical Electronics/Adders


text:
Bartending/Cocktails/Irish Coffee

The Irish Coffee is an Irish classic.

Ingredients

 * 1 shot of Irish whiskey
 * 1-2 teaspoons of sugar
 * Filter coffee
 * Lightly whipped cream

Garnishes

 * Cocoa

Glass

 * Irish Coffee Glass

Instructions

 * 1) Warm whiskey and sugar in heat resistant glass and stir until sugar is dissolved
 * 2) Add coffee
 * 3) Carefully pour lightly whipped cream over the back of a spoon so it floats on the top
 * 4) Garnish with cocoa if you wish
 * 5) Sip hot coffee through the cool cream

กาแฟไอริช

title: Bartending/Cocktails/Irish Coffee


text:
User:Webjunkie

What to write in a user page.

I'm a student. I like puttering around wikibooks and reading things and try and help, or do what I can anyway. Mainly, I like editing spelling/grammer stuff. A lot of that I did before I registered, so, none of it's in my contributions list.

Just looking for a niche. If anyone needs a proof-reader, let me know.

~ The Webjunkie

Areas of Interests/Places of Contribution
Under Law, specifically Contracts (before it was redirected to UK Contracts)

Recent (like, this morning recent) Greek Mythology --Webjunkie 13:16, 6 August 2006 (UTC)

title: User:Webjunkie


text:
Mathematics for Chemistry/Complex Numbers

Introduction to complex numbers
The equation:

$$x^2 + 6 x + 13 = 0$$

Does not factorise

$$x = -3 \pm \sqrt {9-13}$$

$$\sqrt {-4}$$ without complex numbers does not exist. However the number $$i=\sqrt{-1}$$ behaves exactly like any other number in algebra without any anomalies, allowing us to solve this problem.

The solutions are $$-3\pm2i$$.

$$2i$$ is an imaginary number. $$-3-2i$$ is a complex number.

Two complex numbers $$(a,b) = a + ib$$ are added by $$(a,b) + (c,d)                                             =

(a+c,b+d)$$ $$= a+c+i(b+d)$$.

Subtraction is obvious: $$(a,b) - (c,d) = (a-c,b-d)$$.

$$(a,b). (c,d) = ac + i ( ad + bc ) - bd$$

Division can be worked out as an exercise. It requires$$(c+id) (c-id)$$ as a common denominator. This is $$c^2-(id)^2$$, (difference of two squares), and is $$c^2 + d^2$$.

This means

$$\frac {(a,b) } {(c,d)} = \frac {ac+bd+i(cb-ad)} {c^2+d^2}$$

In practice complex numbers allow one to simplify the mathematics of magnetism and angular momentum as well as completing the number system.

There is an apparent one to one correspondence between the Cartesian $$x-y$$ plane and the complex numbers, $$x + iy$$. This is called an Argand diagram. The correspondence is illusory however, because say for example you raise the square root of $$i$$ to a series of ascending powers. Rather than getting larger it goes round and round in circles around the origin. This is not a property of ordinary numbers and is one of the fundamental features of behaviour in the complex plane.

Plot on the same Argand diagram $$2-i,~3i-1,~-2-2i$$

Solve

$$x^2 + 4x +29 = 0$$

$$4x^2 - 12x +25 = 0$$

$$x^2 + 2ix + 1 = 0$$

(Answers -2 plus or minus 5i, 3/2 plus or minus 2i, i(-1 plus or minus root 2)

2 important equations to be familiar with, Euler's equation:

$$e^{i\theta} = \cos \theta + i \sin \theta$$

and de Moivre's theorem:

$${ ( \cos \theta + i \sin \theta ) }^n = \cos n \theta + i \sin n \theta$$

Euler's equation is obvious from looking at the Maclaurin expansion of $$e^{ i\theta}$$.

To find the square root of $$i$$ we use de Moivre's theorem.

$$e^{i\frac \pi 2} = 0 +1i$$

so de Moivre's theorem gives $$\sqrt{e^{i\frac \pi 2}} = \cos \frac \pi {2.2} + i  \sin \frac \pi {2.2}$$

$$= \frac 1 {\sqrt 2} + \frac 1 {\sqrt 2} i$$

Check this by squaring up to give $$i$$.

The other root comes from:

$$\frac {5 \pi} {4} + i \sin \frac {5 \pi} {4} = -\frac 1 {\sqrt 2} - \frac 1 {\sqrt 2} i$$

de Moivre's theorem can be used to find the three cube roots of unity by

$$1 = \cos \theta + i \sin \theta$$

where $$\theta$$ can be $$0 \pm 2 \pi / n$$.

Put $$n=1/3$$, $$\cos \theta = -1 / 2$$ and $$\sin \theta = \pm \sqrt 3 / 2$$

$${\left( - \frac 1 2 + \frac {\sqrt 3} 2 i \right) }^3 = \left(\frac 1 4 - \frac 3 4 -\frac {\sqrt 3} 2 i  \right)\left( - \frac  1 2 + \frac {\sqrt 3} 2 i \right)$$

$$= \left( - \frac 1 2 - \frac {\sqrt 3} 2 i \right)\left( - \frac  1 2 + \frac {\sqrt 3} 2 i \right)$$

This is the difference of two squares so

$${ \left( \frac  1 2 \right) }^2 - \frac 3 4 i^2 =   \frac  1 4 +  \frac 3 4$$

Similarly any collection of $$n$$th roots of 1 can be obtained this way.

Another example is to get the expressions for $$\cos 4 \theta$$ and $$\sin 4 \theta$$ without expanding $$\cos (2 \theta + 2 \theta)$$.

$$\cos 4 \theta + i \sin 4 \theta = { ( \cos \theta + i \sin \theta ) }^4$$

Remember Pascal's Triangle

1                      1   2   1                     1   3   3   1                   1   4   6   4   1                 1   5   10  10  5   1               1   6   15  20  15  6   1

$$= \cos^4 \theta + 4 \cos^3\theta i \sin\theta + 6 \cos^2\theta i^2 \sin^2 \theta + 4 \cos\theta i^3 \sin^3 \theta + i^4 \sin^4 \theta$$

$$= \cos^4 \theta - 6 \cos^2\theta  \sin^2 \theta +  \sin^4 \theta +i ( 4 \cos^3\theta \sin\theta - 4 \cos\theta  \sin^3 \theta)$$

Separating the real and imaginary parts gives the two expressions. This is a lot easier than

$$\cos (2 \theta + 2 \theta)$$

Use the same procedure to get

$$\cos 6 \theta$$ and $$\sin 6 \theta$$.


text:
Converting MySQL to PostgreSQL

Very Short Intro
''You may have read a bunch of short articles with the same name on the web, but they were just snippets of information you needed. It's time to put it all together.''

You have a project in MySQL and suddenly you find out that you need to switch to PostgreSQL. Suddenly you see that there are many flavours of SQL and that your seemingly basic constructions throw a lot of errors. You don't have time to really rewrite your code from scratch, it may come later...

Actually, there may be some good reasons to switch...

 * you can sell your product with total peace of mind (PostgreSQL is BSD licensed, MySQL is more complicated)
 * you can find articles "Converting from MySQL to PostgreSQL" on the web; you won't find any "Converting from PostgreSQL to MySQL"
 * PostgreSQL may not be just another lousy database if Skype, Cisco, Juniper, IMDb, Pandora decided to rely on it and Sun Microsystems made it database of choice (which is explicitly funny because Sun acquired MySQL).

With PostgreSQL you may still feel a little like a second-class citizen, but not really the ignored one. There are some major projects like Asterisk, Horde or DBMail that have recognized its qualities and although MySQL was their first choice database, they are showing effort to make things run here too.

Check that the Server is Running
Most likely you don't need this chapter, but very briefly: after you've installed your package with PostgreSQL on your Linux machine (be it from a package or following these notes), you need to do something like

su - su - postgres createdb test psql test =# create user username password ' password '; -- To change a password: =# alter role username password ' password '; =# create database databasename with encoding 'utf8'; =# grant all privileges on database databasename to username; =# \l =# \c databasename =# \q

vi /etc/postgresql/pg_hba.conf

host   all         all         0.0.0.0           0.0.0.0            md5

be SURE to cover this security issue with iptables!

/etc/init.d/postgresql reload or /usr/lib/postgresql/bin/pg_ctl reload

postmaster successfully signaled

psql -h server -d databasename -U username

databasename=>

Using pgloader
Have a look at http://pgloader.io and you can migrate your MySQL database over to PostgreSQL in a single command:

pgloader mysql://user@localhost/dbname postgresql:///dbname

This will handle type casting with a default casting rules set, and also schema discovery in MySQL and creation in PostgreSQL, including tables, columns, constraints (primary keys, foreign keys, NOT NULL), default values, and secondary indexes. The data are transformed on the fly to be accepted by PostgreSQL, which includes getting rid of zero-dates (there's no year zero in our calendar, neither month nor day zero, and while MySQL doesn't care about that PostgreSQL is quite strongly opinionated that if you use year zero then what you're dealing with is not a date).

For more advanced options or if you want to change the default settings pgloader MySQL support allows you to write a full command using its own language with different rules to describe how you want your migration done.

Common way with SQL dump
Dump your tables with

mysqldump -u username -p --compatible=postgresql databasename > outputfile.sql

but even then you will have to change escaped chars (replacing \t with ^I, \n with ^M, single quote (') with doubled single quote and double (escaped) backslash (\\) with a single backslash). This can't be trivially done with sed command, you may need to write a script for it (Ruby, Perl, etc). There is a MySQL to PostgreSQL python convert script (you need to use  when exporting your mysqldump to make it work). It is much better and proven solution to prepend your dump with the following lines

SET standard_conforming_strings = 'off'; SET backslash_quote = 'on';

These options will force PostgreSQL parser to accept non-ANSI-SQL-compatible escape sequences (Postgre will still issue HINTs on it; you can safely ignore them). Do not set these options globally: this may compromise security of the server!

You also have to manually modify the data types etc. as discussed later.

After you convert your tables, import them the same way you were used to in MySQL, that is

psql -h server -d databasename -U username -f data.sql

Export using CSV-files
When you have a large sql dump containing binary data, it will not be easy to modify the data structure, so there is another way to export your data to PostgreSQL. Mysql have an option to export each table from the database as a separate .sql file with table structure and .txt file with table's data in CSV-format:

mysqldump -u username -p --compatible=postgresql -T /path/to/export databasename

Notice that /path/to/export should be writeable by user who runs mysqld, in most case it mysqld. After that you should modify your table structure according PostgreSQL format: When table structure will be ready, you should load it as it was shown above. You should prepare data files: replace carriage return characters to "\r" and remove invalid characters for your data encoding. Here is an example bash script how you can do this and load all the data in your database: CHARSET="utf-8" #your current database charset DATADIR="/path/to/export" DBNAME="databasename" for file in $DATADIR/*.txt; do  TMP=${file%.*} TABLE=${TMP##*/} echo "preparing $TABLE" #replace carriage return sed 's/\r/\\r/g' $file > /tmp/$TABLE.export.tmp #cleanup non-printable and wrong sequences for current charset iconv -t $CHARSET -f $CHARSET -c < /tmp/$TABLE.export.tmp > /tmp/$TABLE.export.tmp.out echo "loading $TABLE" /usr/bin/psql $DBNAME -c "copy $TABLE from '/tmp/$TABLE.export.tmp.out'" #clean up  rm /tmp/$TABLE.export.tmp /tmp/$TABLE.export.tmp.out done
 * convert data types
 * create separate keys definitions
 * replace escape characters
 * 1) !/bin/bash

Perl
You will need to install an appropriate DBD package. In Debian/Ubuntu run.

Data Types
The ideas for this table were partially derived from automated dump converting script. Official documentation: List of available data types can be reached also by using psql's internal slash command.
 * PostgreSQL 8.4 Data Types
 * MySQL 5.1 Data Types

Language Constructs

 * MySQL 5.1 SQL Statement Syntax
 * PostgreSQL 8.1 SQL Commands
 * PostgreSQL 8.2 SQL Commands

Functions

 * MySQL 5.1 Functions and Operators
 * PostgreSQL SQL Functions and Operators
 * mysqlcompat, a reimplementation of most MySQL functions in PostgreSQL

Common Errors

 * ERROR: relation "something" does not exist - usually table doesn't exist as you probably didn't make it with the new datatypes or syntax. Also watch out for case folding issues; PostgreSQL = postgresql != "PostgreSQL".
 * prepared statement "dbdpg_X" does not exist -

Install
In versions prior to 9.0, you have to make it available explicitly for every database: your_unix$ su - postgres your_unix$ .../pgsql/bin/createlang plpgsql -h localhost -d databasename

(On BSD systems, the username is pgsql)

Running A Function
SELECT definedfunction;

Administration
To use the same backup technique as used with MySQL, in : /dumps/postgresql/*/*.dump.gz { daily rotate 20 dateext nocompress sharedscripts create postrotate for i in $(su - postgres -c "psql --list -t" | awk '{print $1}' | grep -vE '^$|^template[0-9]'); do                       if [ ! -e /dumps/postgresql/$i ]; then mkdir -m 700 /dumps/postgresql/$i; fi                       # compress even in custom format, because it can be compressed more su - postgres -c "pg_dump --format=custom $i" | gzip > /dumps/postgresql/$i/$i.dump.gz               done endscript } /dumps/postgresql/*/*.sql.gz { daily rotate 20 dateext nocompress sharedscripts create postrotate for i in $(su - postgres -c "psql --list -t" | awk '{print $1}' | grep -vE '^$|^template[0-9]'); do                       if [ ! -e /dumps/postgresql/$i ]; then mkdir -m 700 /dumps/postgresql/$i; fi                       su - postgres -c "pg_dump --format=plain $i" | gzip > /dumps/postgresql/$i/$i.sql.gz                done endscript } /dumps/postgresql/*/*.tar.gz { daily rotate 20 dateext nocompress sharedscripts create postrotate for i in $(su - postgres -c "psql --list -t" | awk '{print $1}' | grep -vE '^$|^template[0-9]'); do                       if [ ! -e /dumps/postgresql/$i ]; then mkdir -m 700 /dumps/postgresql/$i; fi                       su - postgres -c "pg_dump --format=tar $i" | gzip > /dumps/postgresql/$i/$i.tar.gz                done endscript }

Related wikibooks

 * MySQL
 * PostgreSQL

title: Converting MySQL to PostgreSQL


text:
Mathematics for Chemistry/Some Mathematical Examples applied to Chemistry

Variable names
The ubiquitous $$x$$ is not always the variable as you will all know by now. One problem dealing with real applications is sorting out which symbols are the variables and which are constants. (If you look very carefully at professionally set equations in text books you should find that there are rules that constants are set in Roman type, i.e. straight letters and variables in italics. Do not rely on this as it is often ignored.)

Here are some examples where the variable is conventionally something other than $$x$$.

 * 1) The Euler angles which are used in rotation are conventionally  $$\alpha, \beta$$ and $$\gamma$$ not the more usual angle names $$\theta$$ and $$\phi$$. The rotation matrix for the final twist in the commonest Euler definition therefore looks like $$\begin{bmatrix}\cos (\gamma) & \sin (\gamma) & 0 \\-\sin (\gamma) & \cos (\gamma) & 0 \\0 & 0 & 1 \\\end{bmatrix}$$
 * 2) The energy transitions in the hydrogen atom which give the Balmer series are given by the formula $$\tilde {\nu } = {\rm R_H} \left(  \frac 1 {2^2}  - \frac 1 {n^2} \right)$$ $$\tilde {\nu }$$ is just a single variable for the energy the tilde  being a convention used by spectroscopists to say it is wavenumbers, (cm-1). The H subscript on $${\rm R_H} $$ has no mathematical meaning. It is the Rydberg constant and is therefore in Roman type. $${\rm R_H} $$ is known very accurately as 109,677.581 cm-1. It has actually been known for a substantial fraction of the class to make an error  putting this fraction over a common denominator in examination conditions.
 * 3) In the theory of light $$\omega$$ is used for frequency and $$t$$ not surprisingly for time. Light is an oscillating electric and magnetic field therefore the cosine function is a very good way of describing it. You can also see here the use of complex numbers. Using the real axis of the Argand diagram for the electric field and the imaginary axis for the magnetic field is a very natural description mathematically and maps ideally onto the physical reality. Here we are integrating with respect to $$t$$ and $$\omega$$, the operating frequency if it is a laser experiment is a constant, therefore it appears on the denominator in the integration. $$\int \cos ( \omega t) \sin ( \omega t) dt = -{\frac {\cos(\omega )^{2}}{2\,\omega}} + c$$ In this case we can see a physical interpretation for the integration constant. It will be a phase factor. If we were dealing with sunlight we might well be integrating a different function over $$\omega$$ in order to calculate all of the phenomenon which has different strengths at the different light frequencies. Our integration limits would either be from zero to infinity or perhaps over the range of energies which correspond to visible light.
 * 4) This example is a laser experiment called Second Harmonic Generation. There is an electric field $$F$$, frequency $$\nu$$ and a property constant $$ \chi_{(2)}$$. $$\epsilon_{0} $$ is a fundamental constant. We have  an  intense  monochromatic laser field fluctuating at the frequency $$\nu$$, (i.e. a strong light beam from a big laser). $$F_{v} \sin (2\pi \nu t)$$ Therefore the $$F^{2}$$ term contributes $$\epsilon_{0} \chi_{(2)} F_{v}^{2} \sin^{2}(2 \pi \nu t )$$ to the polarization. We know from trigonometric identities that $$\sin^{2}$$ can be represented as a cosine of the double angle $$\cos ( 2 \theta ) = 1 - 2 \sin^{2}\theta$$ Therefore the polarization is $$\frac 1 2 \epsilon_{0}\chi_{(2)}F_{v}^{2} ( 1 - \cos 4 \pi \nu t )$$ In this forest of subscripts and Greek letters the important point is that there are two terms contributing to the output coming from $$( 1 - \cos 4 \pi \nu t )$$ which multiplies the rest of the stuff. In summary we have $$A \sin^{2}( t )$$ is equal to $$B ( 1 - \cos( 2 t ) )$$ where everything except the trig(t) and trig(2t) are to some extent unimportant for the phenomenon of doubling the frequency. $$\sin$$ and $$\cos$$ differ only in a phase shift so they represent the same physical phenomenon, i.e. light, which has phase. (One of the important properties of laser light is that it is coherent, i.e. it all has the same phase. This is fundamentally embedded in our mathematics.)

van der Waals Energy
The van der Waals energy between two inert gas atoms can be written simply as a function of $$r$$

$$E_{vdw} = \frac {\rm A} {r^{12}} -  \frac {\rm B} {r^{6}}$$

Notice that the $$r^{12}$$ term is positive corresponding to repulsion. The $$r^{6}$$ term is the attractive term and is negative corresponding to a reduction in energy. A and B are constants fitted to experimental numbers.

This function is very easy to both differentiate and integrate. Work these out. In a gas simulation you would use the derivative to calculate the forces on the atoms and would integrate Newton's equations to find out where the atoms will be next.

Another potential which is used is:

$$E_{vdw} = {\rm A} e ^{- {\rm B} r} - {\rm C} r ^{-6}$$

This has 1 more fittable constant. Integrate and differentiate this.

The $$\frac {\rm A} {r^{12}} - \frac {\rm B} {r^{6}}$$ is called a Lennard-Jones potential and is often expressed using the 2 parameters of an energy $$\epsilon$$ and a distance $$\sigma$$.

$$E(r) = 4 \epsilon \left( { { \left( \frac \sigma r \right) } ^ {12} - { \left( \frac \sigma r \right) } ^ 6 } \right)$$

$$\epsilon$$ is an energy. Set the derivative of this to zero and find out where the van der Waals minimum is. Differentiate again and show that the derivative is positive, therefore the well is a minimum, not a turning point.

A diatomic potential energy surface

In a diatomic molecule the energy is expanded as the bond stretches in a polynomial. We set $$x = ( r - r_0 )$$. At $$r_0$$ the function is a minimum so there is no $$ dE / dx$$ term.

$$E = \frac 1 2 k_{harm.} \frac {{\rm d}^2 E} {{\rm d} x^2} +  \frac 1 6 k_{anharm.} \frac {{\rm d}^3 E} {{\rm d} x^3}$$

Whatever function is chosen to provide the energy setting the 1st derivative to zero will be required to calculate $$r_0$$. The 2nd and 3rd derivatives will then need to be evaluated to give the shape of the potential and hence the infra-red spectrum. $$E$$ is usually modelled by a very complicated function whose differentiation is not entered into lightly.

A one-dimensional metal
A one-dimensional metal is modelled by an infinite chain of atoms 150 picometres apart. If the metal is lithium each nucleus has charge 3 and its electrons are modelled by the function

$$cos^2\left\{ \frac \pi 2 \frac r {150} \right\}$$

which repeats every 150 pm. What constant must this function be multiplied by to ensure there are 3 electrons on each atom? (Hint... integrate $$cos^2$$ between either $$-\frac \pi 2$$ and $$+\frac \pi  2$$ or -75pm and +75pm according to your equation. This integral is a dimensionless number equal to the number of electrons, so we will have to multiply by a normalisation constant.)

Here we have modelled the density of electrons. Later in the second year you will see electronic structure more accurately described by functions for each independent electron called orbitals. These are subject to rigorous mathematical requirements which means they are quite fun to calculate.

Kepler's Laws
Another physics problem but a good example of a log-log plot is the radius and time period relations of the planets.

This data is dimensionless because we have divided by the time / distance of the earth. We can take logs of both.

Try a least squares fit on your spreadsheet program. Using the Earth and Saturn data: (which is extremely bad laboratory practice, to usejust two points from a data set!)

$$\Delta({\log} T ) / \Delta({\log} r ) = 1.5000359$$

so $${\log} T = 1.5 {\log} r = {\log} r^{1.5}$$

so $$ T = r^{3/2}$$  and $$T^2 = r^3$$

This is Kepler's 3rd law. If you use either a least squares fit gradient or the mercury to saturn data you get the same powers. We have got away with not using a full data set because the numbers given are unusually accurate and to some extent tautological, (remember the planets go round in ellipses not circles!).

Newton's law of cooling
$$\theta$$ is the excess temperature of a cooling body over room temperature (20oC say). The rate of cooling is proportional to the excess temperature.

$$-\frac {{\rm d} \theta} { {\rm d} t} = k \theta$$

$${\rm using }\frac {{\rm d} x} { {\rm d} y} = \frac 1{ \frac {{\rm d} y} { {\rm d} x} }$$

$$\frac {{\rm d} t} { {\rm d} \theta} = - \frac 1 {k \theta}$$

This is a differential equation which we integrate with respect to $$\theta$$ to get

$$t = - \frac 1 k \ln \theta + c$$

The water is heated to $$80^o$$C and room temperature is $$20^o$$C. At the beginning $$t = 0$$ and $$\theta = 60$$, so

$$0 = - \frac 1 k \ln 60 + c$$

therefore

$$c = \frac {\ln 60} k$$

$$t = - \frac 1 k \ln \theta + \frac 1 k \ln 60$$

but $$\ln 60 -\ln \theta = - \ln {\frac \theta {60}}$$

so $$\ln {\frac \theta {60}} = - k t$$

After 5 minutes the water has cooled to $$70^o$$C.

so $$\ln {\frac {50} {60}} = - 5k $$ so k = - \frac 1 5 \ln \frac 5 6 =  \frac 1 5 \ln \frac  6  5. So $$k = 0.0365$$

$$\ln{\frac \theta {60}} = -0.0365 t$$

$$\frac \theta {60} = e ^{-0.0365 t}$$

by the definition of logarithms. This gives the plot of an exponential decay between 80 and 20oC.

So after 10 minutes $$t = 20 + 60 e^{-0.365} = 61.6^o$$C. After 20 minutes $$t = 20 + 60 e^{-0.73} = 49.9^o$$C. After 30 minutes $$t = 20 + 60 e^{-1.10} = 40.1^o$$C.

Bacterial Growth
2 grams of an organism grows by 1/10 gram per day per gram.

$$\frac {{\rm d} m} { {\rm d} t} = \frac m {10}$$

This is a differential equation which is solved by integration thus

$$\int \frac {10} m {\rm d} m = \int { {\rm d} t}$$

$$10 \ln m = t + c$$

$$\ln m = \frac t {10} + c$$

therefore

$$m = e^c e^{\frac t {10}}$$

When $$t = 0 $$ we have 2 grams so

$$m = 2 e^{t/10}$$

For the sample to double in mass

$$4 = 2 e^{t/10}$$

$$2 = e^{t/10}$$

$$\ln 2 = \frac t {10}$$

$$t = 10 \ln 2 = 6.9315 {\rm days}$$

Half life calculations are similar but the exponent is negative.

Partial fractions for the 2nd order rate equation
In chemistry work you will probably be doing the 2nd order rate equation which requires partial fractions in order to do the integrals.

If you remember we have something like

$$\frac{1}{(2-x)(3-x)} = \frac{A}{(2-x)} + \frac{B}{(3-x)}$$

Put the right-hand side over a common denominator

$$\frac{1}{(2-x)(3-x)} = \frac{A(3-x)+B(2-x)}{(2-x)(3-x)}$$

This gives $$1 = 3A - Ax + 2B - Bx$$

By setting x to 3 we get 1 = -B (B=-1). Setting x = 0 and B = -1

1 = 3A -2    (A=+1)

Check   1 = 3 -x -2 +x  true...

Therefore

$$\int \frac{1}{(2-x)(3-x)} dx = \int\frac{1}{(2-x)} - \int\frac{1}{(3-x)} dx = \ln (2-x) + \ln (3-x) + c$$

noting the sign changes on integrating 1/(2-x) not 1/x.


text:
Mathematics for Chemistry/Some Useful Aspects of Calculus

Limits
Many textbooks go through the proper theory of differentiation and integration by using limits. As chemists it is possible to live without knowing this so we might well not have it as an examinable topic. However here is how we differentiate sin from 1st principles.

$$\frac {{\rm d} y} { {\rm d} x} = \left( \frac {{\delta} y} { {\delta} x} \right)_{{\rm limit}~ \delta x \rightarrow 0}$$

$$= \frac { \sin (x + \delta x) - \sin x} {\delta x}$$

$$= \frac { \sin x \cos \delta x +\sin \delta x \cos  x - \sin x} {\delta x}$$

$$= \frac { \sin x } {\delta x} - \frac { \sin x } {\delta x} + \frac { \sin \delta x } {\delta x} \cos x$$

As $$ \sin \delta x = \delta x$$ for small $$x$$ this expression is $$\cos x$$.

Similarly for $$\cos \theta$$

$$\frac {{\rm d} y} { {\rm d} \theta} = \frac { \cos (\theta + \delta \theta) - \cos \theta} {\delta \theta}$$

$$= \frac { \cos \theta \cos \delta \theta -sin  \theta \sin \delta  \theta - \cos \theta} {\delta \theta}$$

$$= \frac { \cos \theta } {\delta \theta} - \frac { \sin \theta \delta \theta} {\delta \theta} - \frac { \cos \theta } {\delta \theta}$$

This is equal to $$- \sin \theta $$.

Numerical differentiation
You may be aware that you can fit a quadratic to 3 points, a cubic to 4 points, a quartic to 5 etc. If you differentiate a function numerically by having two values of the function $$\delta x$$ apart you get an approximation to $$\frac {{\rm d} y} { {\rm d} x}$$ by constructing a triangle and the gradient is the tangent. There is a forward triangle and a backward triangle depending on the sign of $$\delta x$$. These are the forward and backward differentiation approximations.

If however you have a central value with a $$\delta$$ either side you get the central difference formula which is equivalent to fitting a quadratic, and so is second order in the small value of $$\delta x$$ giving high accuracy compared with drawing a tangent. It is possible to derive this formula by fitting a quadratic and differentiating it to give:

$$\frac {{\rm d} y} { {\rm d} x} = \frac { f^+ + f^- - 2  f^0 } {\delta^2}$$

HCl  r-0.02 sigma (iso)      32.606716      142.905788     -110.299071

HCl  r-0.01 sigma (iso)      32.427188      142.364814     -109.937626

HCl  r0         Total shielding: paramagnetic  : diamagnetic sigma (iso)      32.249753      141.827855     -109.578102

HCl  r+0.01 sigma (iso)      32.074384      141.294870     -109.220487

HCl  r+0.02 sigma (iso)      31.901050      140.765819     -108.864769

This is calculated data for the shielding in ppm of the proton in HCl when the bondlength is stretched or compressed by 0.01 of an Angstrom (not the approved unit pm). The total shielding is the sum of two parts, the paramagnetic and the diamagnetic. Notice we have retained a lot of significant figures in this data, always necessary when doing numerical differentiation.

Exercise - use numerical differentiation to calculated $$d\sigma/dr$$and $$d^2\sigma /dr^2$$using a step of 0.01 and also with 0.02. Use 0.01 to calculate $$d\sigma (para)/dr$$ and $$d\sigma (dia)/dr$$

Numerical integration
Wikipedia has explanations of the Trapezium rule and Simpson's Rule. Later you will use computer programs which have more sophisticated versions of these rules called Gaussian quadratures inside them. You will only need to know about these if you do a numerical project later in the course. Chebyshev quadratures are another version of this procedure which are specially optimised for integrating noisy data coming from an experimental source. The mathematical derivation averages rather than amplifies the noise in a clever way.


text:
User talk:CQuinton~enwikibooks

started 21:35, 5 August 2006 (UTC)

Community studies
I plan to start a Module on Community studies under Sociology. The focus at this time is on the Wikipedia article of the same name. If interested in helping out, please meet me there. Thanks! • CQuinton 21:43, 5 August 2006 (UTC)

Perl
I got your message on my talk page, thank you for contacting me. I am still interested in Perl, but unfortunately I am also highly interested in wikibooks (at the expense of being uninterested in other wikiprojects). Thank you for inviting me to your wikia and wikiversity projects, but I only have the time, energy, and motivation to contribute here at wikibooks.

However, if other people on wikiversity, wikia, etc. are interesting in working on a collaborative bot project, we could start a project on sourceforge or something, and then use the resulting bot on our own projects. --Whiteknight (talk) (projects) 01:05, 11 October 2006 (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 CQuinton. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name CQuinton~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 23:04, 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) 04:44, 19 April 2015 (UTC)

title: User talk:CQuinton~enwikibooks


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Template:Code/doc

Documentation
The purpose of this series of templates is to increase the readability of code examples in programming books. Each template includes a div with an colored outline and colored background, and a second div with a colored outline and white background. Inside the first div is a space which allows a comment or other instruction; inside the second div is the code space. The include code is used along with two arguments, the first being the comment and the second being the code.

Due to parsing limitations, the current version of the code template requires the user to include

 tags around the code sample. (Inclusion of the

 tags causes the wiki parser to render the wiki include code as plain text instead of parsing it.) This may change if I am able to hack around the parser and insert the include tag manually. (Note you can now do this using Yan (talk) 21:38, 13 November 2008 (UTC))

Templates initially created by banzaimonkey 01:04, 6 August 2006 (UTC) for the PHP wikibook. These templates are intended to be usable in all programming wikibooks, but specific alterations or exceptions may be required for a particular programming language. Please be extremely careful when modifying these templates, as your changes may be propagated across a large number of pages unbeknownst to you. If you'd like to use a code template that is not described below, feel free to add your own and include it in the list (please also include the "Code Template" category on each new template's page, inside <noinclude></noinclude> tags; see an existing template as an example).

Another concern I have is that these will add large sections of color to "Print" pages on wikibooks that use them, thus vastly increasing printing costs. If anyone has a suggestion on how to filter these to white (see template Misc2, below), please leave a note on the discussion page.

Why Use Code Templates?
''Why use code templates? Isn't there already a blue box around code?''

The design presentation using the code template / code box highlights the code much more obviously, allowing the reader to see the code much more easily. Thus, the user is able to focus his or her energy on parsing the code only, rather than having to parse the wiki page to figure out which sections actually are code. Because there is room for comment text inside the code template, it is easier to attach a specific note, instruction, or link to a particular piece of code. This affords the author greater clarity when making reference to code examples. The code template also allows the code to be easily recognized and edited inside the wiki source because it has distinct bracketing (from the template code itself). Finally, some of the alternate stylesheets to not designate code with anything more than monospace font.

Usage Notes

 * I highly recommend the use of

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 * With the inclusion of the Highlight extension to wikibooks, you can now use <source lang="x"> </source> which is automatically converted to

 with colour-formatted code.
 * All code templates must include the correct number of vertical lines |, even if the argument is blank. If you don't want to enter text after a particular argument, that's fine, but you still need the vertical line.

Code Templates

 * Template:Code:Basic - Show basic programming example without any other features
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Code:Basic
This box can show code or simply be used to highlight a particular section of text with a blue outline.

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Code:Tip
It's a good idea to add comments to your code.

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It's a good idea to add comments to your code.

Code:Transclude
This can be used to create a transcluded, titled page, like so Template_talk:Code:Transclude

title: Template:Code/doc


text: Template:Code:Valid

title: Template:Code:Valid


text: Template:Code:Error

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text: Template:Code:Output

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text: Template:Code:Tip

title: Template:Code:Tip


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Screen Printing/Planning and Executing your Project

A Brief Overview
In screenprinting, you use a fine mesh material, stretched over a frame, to produce a stencil by blocking parts of the screen with filler material. One of the most popular and effective methods is by using a photo-sensitive material called photo emulsion which hardens when exposed to light. We will describe the process of using this substance to make stencils suitable for screenprinting in the section "Making the Stencil". Once you have a stencil, you use it as a pattern for transfering ink onto your printing surface. The screen helps to prevent you from using too much ink and allows a very sharp edged design to be printed, with a little practice. The screen also allows you to deposit the ink more evenly, and more easily, over the printing surface to help create consistent prints.

The process of creating the stencil can take a few days, but once it's created, printing is fast and easy. You can also save stencils indefinitely for reuse, so those few days are a one time deal for each stencil.

Fabric/Paper

 * Keep in mind, when transferring to different materials, different ink will be necessary

Inks
Many inks available for different materials. Brand list:
 * Speedball
 * $20 for pack of six

Printing Frame

 * Making one
 * Buying one
 * Makeshift frames
 * Embroidery hoops
 * Usually under two dollars

Screen Material
What to keep in mind
 * Nylon
 * Tulle
 * Silk


text:
Cookbook:Fruity Cheese Dogs

Ingredients

 * 2 jumbo hot dogs
 * 1 cup (240 ml) cheese (Mozzarella, Cheddar, Swiss, or any cheese that melts easily and is not very creamy)
 * ⅛ cup (30 ml) crushed froot loops (or any equivalent fruity breakfast cereal)

Procedure

 * 1) Cook the hot dogs in any manner; the original recipe used a pan on a stove, but a toaster oven would suffice.
 * 2) Once the hot dogs have cooked and split, remove them from the heat.
 * 3) Melt the cheese either in the oven or the microwave (microwave works best). Pour the melted cheese on the hot dogs.
 * 4) Sprinkle the crushed Froot Loops over the cheese, and let cool.

Notes, tips, and variations

 * This recipe works best when the hot dogs are closer together on the serving plate so that any stray Froot Loops are caught in between.

title: Cookbook:Fruity Cheese Dogs


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Template:Code:Basic

 * Purpose:This template matches the styling of more involved two part templates ginned together to write about software languages (Code). It's purpose is theory or narrative exposition and an example below:
 * Actual Wikibook use example:

As usual, avoid spaces in between the braces. Here's an example that demonstrates how this syntax works:

Default value assignment

As with the default value syntax, the colon is optional.

As usual, avoid spaces in between the braces. Here's an example that demonstrates how this syntax works:

Default value assignment

As with the default value syntax, the colon is optional.

title: Template:Code:Basic


text:
User:Kenwolcott

Freelance web designer and linguistics student extraordinaire.

title: User:Kenwolcott


text:
Template:Code:PHPHTML

 PHP Code:  PHP Output:  HTML Render:

title: Template:Code:PHPHTML


text: Template:Code:Alt

title: Template:Code:Alt


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Talk:Haskell/Archive 1

It might be useful if we asked people on the Haskell Wiki if we could use their material. http://www.haskell.org/hawiki/. If i'm not mistaken, there's no expicit license, so we'll either have to contact editors individually or find some sort of collective policy, or make some sort of announcment. -- Kowey 11:19, 21 Feb 2004 (UTC)

 * anyway, i've put put a page here http://www.haskell.org/hawiki/UsingHaskellWikiMaterial

 * Yippee! The new Haskell wiki has a simple permissive license. I guess this means anything that goes on the new wiki can go here.  -- Kowey 09:56, 14 January 2006 (UTC)

I've also got permission from Jeff Newburn to rip material from his "All about monads" tutorial (which is the one thing that enabled me to understand the damn things!). -- Paul Johnson 19:05, 2 Jan 2006 (GMT)

 * Cool! We could also mix and match with stuff from my tutorial, Of Monads and Spacesuits, not to self-plug or anything :-) -- Kowey 19:47, 2 January 2006 (UTC)

Hmmm. I've had a look, and I like the idea. However having space stations processing astronauts does seem a bit of a stretch. How about having machines processing bits of nuclear waste. Each machine must always ensure that the waste leaves it in a sealed conatiner. This also allows us to have a machine that takes several containers of material and puts the contents into a single container, which is what sequence does (the thought of several astronauts in a spacesuit, while comic, does stretch things a bit far I think). -- Paul Johnson 23:13, 3 Jan 2006 (GMT)

 * Heh. :-) I tend to think of multiple astronauts in a suit as just being in a space shuttle.  Maybe I could say that explicitly to make it easier to swallow.  As for nuclear waste, we should try it!  I tend to believe that we've got grab a whole of different metaphors and flesh them completely out until one of them fits nicely enough or until we cover enough readers' mental models.  The Jeff Newburn assembly line and tray metaphor might also work.  I guess we're all just instances of Cale Gibbard's monad as container idea.  Whatever we do, I'd prefer that the metaphor have nothing to do whatsover with computers.  See below for more thoughts -- Kowey 20:27, 4 January 2006 (UTC)

Monadic metaphors
Nuclear waste. How should we go about explaining the state monad? What would you is a good way to represent the lambda (ticket) in a nuclear waste metaphor? -- Kowey 20:27, 4 January 2006 (UTC)

 * I would say that each container contains both some waste and a ticket describing the state of the waste. Each machine modifies the waste and updates the ticket.  You can also move the ticket into the waste compartment (get) or put some waste in the ticket compartment (put).  Aside: Dell use a ticket called a "traveller" in their build-to-order manufacturing system, which parallels this system closely except for the rule about sealed containers.

 * Paul.

 * Hmm... of course. The notion of 'ticket' could be very easily transfered over to the waste container thing.  Don't know why that didn't occur to me.  Ok, so now what?  Do we start importing text?  Are there other issues to work out? -- Kowey 20:37, 8 January 2006 (UTC)

 * I think we can start importing text. I know I haven't been active recently.  I'm hoping to get back to this soon.  BTW, thanks for getting started with the "Practical Haskell" bit.  -- Paul Johnson 22:31, 10 Jan 2006 (GMT)

From the main page... ''What is almost unique about Haskell is that it is purely functional. If you have a function f on integers, then it really is a function. For exampele f(x) - f(x) will always be zero, you don't need to know the definition of f.'' This statement is at best misleading, and at worst, false. Ignoring for a moment that f(x) will have to be in the class Num (because of the subtraction) in order for your program to compile, it is trivially easy to come up with examples where f(x) - f(x) isn't zero...

main = do       print $ f - f        print $ g - g f :: Double f = 1/0 g :: Integer g = 1 `div` 0

 * I've fixed the f x - f x problem.

Operators
I see we have a bit of minor dispute over how infix functions should be referenced. The articles previously used things like ">>=", and I've been using >>=. I actually prefer (>>=) because that is the way it would be written as a "normal" function. Should I go in and put quotation marks around all those operators, or should we use one of the others? --Ihope127 16:40, 31 December 2005 (UTC)

 * I've been a bit inconsistent myself, mostly as a result of the learning curve on WikiBooks markup. I'm now using <tt> .. </tt> to flag Haskell keywords and identifiers when used in-line.  I don't want to use brackets around infix operators because it adds visual clutter for newbies, even though it is technically correct.

 * --Paul Johnson 19:05, 2 January 2006 (GMT).

How about quotation marks the first time, and nothing after that? --Ihope127 02:28, 3 January 2006 (UTC)

 * I have no strong views, other than a wish to avoid work and be consistent. If you feel strongly enough to go back and fix everything then I'll be happy to fit in with the convention from now on.  Whatever we do ought to be documented in the notes for contributors though.  --Paul Johnson 23:15, 3 January 2006 (GMT).

 * How about ? That code tag is mighty handy -- Kowey 14:04, 4 February 2006 (UTC)

A CPS draftything
Since talk pages for nonexistent pages never get noticed: Talk:Programming:Haskell_CPS --Ihope127 17:01, 3 February 2006 (UTC)

Metaphor corral
Just a place for just to jot down useful metaphors and mental images for explaining Haskell or functional programming stuff. Of course, not everything needs a metaphor. Somethings are best explained directly...

 * monads - nuclear waste containers
 * monad transformers - monadic sandwiches
 * Parsec - Pacman! (you can use try to make it spit the pills back out)

Renaming
We need to rename the pages, as per Naming policy.

 * It's not entirely clear to me what to rename it to. Can we just name it Haskell? -- Kowey 19:15, 13 June 2006 (UTC)

 * Rename to things like:
 * Haskell (Probably without Programming:)
 * Haskell/Beginning_Haskell
 * Haskell/Beginning_Haskell/Basic_Concepts
 * Haskell/Beginning_Haskell/Lists
 * etc...
 * Haskell/The_Libraries
 * Haskell/The_Libraries/The_Hierarchical_Libraries
 * etc...
 * --Tchakkazulu 22:38, 13 June 2006 (UTC)

 * Works for me, although I would probably just keep the structure pretty flat
 * Haskell/Basic_concepts
 * Haskell/Lists
 * etc...
 * You agree? Anybody else want to comment? -- Kowey 17:25, 14 June 2006 (UTC)
 * You agree? Anybody else want to comment? -- Kowey 17:25, 14 June 2006 (UTC)

 * Starting the move now. Please help, or complain if you disagree -- Kowey 06:11, 16 June 2006 (UTC)

Write yourself a Scheme in 48 hours
Johnathan Tang has given just permission to import Write yourself a Scheme in 48 hours into the wikibook! There's great material for Parsec and practical Haskell that we could mine from this book. Many thanks, Johnathan. -- Kowey 17:24, 14 June 2006 (UTC)

 * Note that this import is now complete, and can be found at Haskell/Write Yourself a Scheme in 48 Hours - now all the remains is to mine it for content in the main wikibook -- Kowey 00:33, 9 July 2006 (UTC)

Use of the term 'statement'
The only appropriate place to use the term 'statement' is in the context of the lines of a do-block (but not for the do-block as a whole, or in reference to let or if). It's used in error in a bunch of places here, try to correct any incorrect uses you see.

 * Thanks for pointing this out. Would the appropriate fix be s/statement/expression/ where relevant? -- Kowey 09:20, 21 June 2006 (UTC)

PLEAC code considered harmful
I've removed the link to PLEAC, because the code there isn't educational. The code is barely recognizable as Haskell. For example, the author overrides the (.) operator (usually used for function composition) to an OO like application operator. (^) is changed from exponentation to concatenation. These are just a few of the problems at PLEAC; we really can't recommend this material to those learning Haskell.

title: Talk:Haskell/Archive 1


text:
User:Nguyenthephuc

Wikipedian from Vietnam.

Interwiki

 * vi:Thành viên:Nguyenthephuc
 * vlos:Thành viên:Nguyenthephuc
 * meta:User:Nguyenthephuc

title: User:Nguyenthephuc


text:
User:BrisbanePom

My Sandbox. Planning to create a SAS programming Wikibook. Using Ada programming as a template; once I have something workable in place, I will launch the book.

Welcome to the SAS Programming tutorial at Wikibooks. This book was started in August 2006 to provide a template for the first foray into SAS programming in the Wikibooks world. It is hoped that memebrs of the SAS development community will recognise the value in having a centralised teaching resource for SAS programming and contribute accordingly. In particular, links to the many papers presented at various SAS conferences around the world and over the years are very much encouraged.

Current Development Stage for SAS Programming is "". It's a lengthy road ahead, but it has to begin somewhere!

Please feel free to contribute (that's what a Wikibook is all about) and please spread the word amongst SAS developers everywhere that this book is now here.

About SAS
The SAS System, (originally referring to the Statistical Analysis System), is an integrated suite of software products used to perform a number of data and statistical analysis operations. Whilst specialist sub-products exist within the SAS Sytem, some of which use a graphical interface (e.g. the data-mining tool SAS Enterprise Miner), the core programming language that underpins all of these tools is Base SAS.

In addition, the SAS System integrates with many SAS business solutions that enable large scale software solutions for areas such as human resource management, financial management, business intelligence, customer relationship management and more.

Description of SAS
SAS is driven by SAS programs that define a sequence of operations to be performed on data stored as tables. Although non-programmer graphical user interfaces to SAS exist (such as the SAS Enterprise Guide), most of the time these GUIs are just a front-end to automate or facilitate generation of SAS programs. SAS components expose their functionalities via application programming interfaces, in the form of statements and procedures.

A SAS program is composed of three major parts, the DATA step, procedure steps (effectively, everything that is not enclosed in a DATA step), and a macro language. SAS Library Engines and Remote Library Services allow access to data stored in external data structures and on remote computer platforms.

The DATA step section of a SAS program, like other database-oriented fourth-generation programming languages such as SQL or Focus, assumes a default file structure, and automates the process of identifying files to the operating system, opening the input file, reading the next record, opening the output file, writing the next record, and closing the files. This allows the user/programmer to concentrate on the details of working with the data within each record, in effect working almost entirely within an implicit program loop that runs for each record.

All other tasks are accomplished by procedures that operate on the dataset (SAS' terminology for "table") as a whole. Typical tasks include printing or performing statistical analysis, and may just require the user/programmer to identify the dataset. Procedures are not restricted to only one behavior and thus allow extensive customization, controlled by mini-languages defined within the procedures. SAS also has an extensive SQL procedure, allowing SQL programmers to use the system with little additional knowledge.

There are macro programming extensions, that allow for rationalization of repetitive sections of the program. Proper imperative and procedural programming constructs can be simulated by use of the "open code" macros or the SAS/IML component.

Macro code in a SAS program, if any, undergoes preprocessing. At runtime, DATA steps are compiled and procedures are interpreted and run in the sequence they appear in the SAS program. A SAS program requires the SAS System to run.

Compared to general-purpose programming languages, this structure allows the user/programmer to be less familiar with the technical details of the data and how it is stored, and relatively more familiar with the information contained in the data. This blurs the line between user and programmer, appealing to individuals who fall more into the 'business' or 'research' area and less in the 'information technology' area, since SAS does not enforce (although SAS recommends) a structured, centralized approach to data and infrastructure management.

The SAS System runs on IBM mainframes, Unix machines, OpenVMS Alpha, and Microsoft Windows; and code is almost transparently moved between these environments. Older versions have supported PC-DOS, the Apple Macintosh, VMS, VM/CMS and OS/2.

Introduction to SAS
An overview of the wider SAS system and it's role in businesses today, followed by an introduction to the Base SAS product and a description of the SAS programming language in comparison to more 'traditional' languages.

 * Overview of the SAS system —
 * Introduction to Base SAS —
 * Basic language concepts —

Basic Data manipulation
These chapters look at the first steps needed to handle data using SAS.

 * Importing and creating data —
 * The data step - fundamental functions and statements —
 * Essential SAS procedures - sorting and summarising data —
 * Modifying and combining data sets (Merge, Set, Transpose) —
 * Generation of data output and exporting data —

Making the most of Base SAS; advanced concepts
Beyond the basic data handling concepts outlined in the previous chapters, Base SAS offers powerful functionality to the user. In addition to a wealth of statistical procedures, SAS is supported b a macro language to enable users to automate program execution. Recent developments with the ODS system allow users to create professional graphical and web output.

 * The Enhanced Editor - managing the programming environment —
 * Statistical and advanced procedures in Base SAS —
 * Automating data steps - the SAS Macro language —
 * Generating output using the Output Delivery System (ODS) —
 * Manipulating variables through the use of arrays —

Beyond Base SAS
Base SAS is only the beginning of learning to use SAS; a host of specialist products also exist to perform advanced tasks. These chapters give an overview and focus on some of the key products you may encounter.
 * Overview of other SAS modules —
 * SAS/STAT —
 * SAS/Graph —
 * SAS/Access and SAS/Connect —
 * SAS/Enterprise Guide —
 * Data mining with SAS/Enterprise Miner —
 * Other SAS products —

External resources
Collections of Links to various SAS user websites and presented conference papers.
 * SAS user groups and user pages —
 * Index of referenced conference papers —
 * SAS-L at University of Georgia (SAS User helproom)

Authors and contributors
This Wikibook has been written by:

 * Stuart Edwards (Contributions)

If you wish to contribute as well you should read Contributing and join us at the Contributors lounge.

title: User:BrisbanePom


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User talk:Webjunkie

Meh.

I was just tired of the "discussion" and "talk" links being red.

title: User talk:Webjunkie


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Talk:Windows Programming/Programming Windows with OSS Tools

Cygwin
Added some Cygwin support. DevCpp would be nice too, though I am not sure how Windows are it is. It lacks a GUI design tool, though it has support for win32 and opengl, as well as SDL and allegro and many other programs. It uses addons for that purpose. Its latest features include code completion, which is a nice detail that other open source C++ compilers don't seem to have on Windows.

PS: Nice to see that this wikibook has progressed since the beginning of the year. I had been here before and noticed too many empty entries that have apparently been at least stubbified this time around. I have interest in the content, as well as providing some in-depth Cygwin details from my personal installation and a few years of using it for simple tasks and X. --64.131.175.112 09:56, 6 August 2006 (UTC)

 * I personally use Dev-C++ for my own work, so i really should have added a section about it in here. This book does still need alot of work, and I've been focusing alot of my attention on the Reverse Engineering book recently, because it is the current collaboration of the Month. Any help is certainly appreciated, however. --Whiteknight (talk) (projects) 17:49, 6 August 2006 (UTC)

 * I don't agree with the "arduous" set up of VC++ Express assertion ! I downloaded it last week along with the full Plateform SDK, installled them, and merged docmentation (you need to go to a special ms-help://.. URL in the MS document explorer to do that). It all took few minutes and worked the first time on a pretty large application I compiled. See http://msdn.microsoft.com/vstudio/express/visualc/usingpsdk/.

Hello there, great book, I am still reading it. I belive the Tiny C Compiler is also a good choice for people looking for a simple command line compiler, I have already compiled a couple Windows C programs and it seem to work very well, perhaps it could be included if you agree. --Keylor.gonzalez (talk) 15:52, 28 October 2009 (UTC)


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Talk:Understanding Darcs

The diagrams
Note: I've updated the darcs model pictures using Heffalump's suggestions (colour the _darcs stuff differently, if I recall correctly) and some new ideas I had. Also, you can download the OmniGraffle XML sources on my homepage. -- Kowey 11:32, 6 August 2006 (UTC)

title: Talk:Understanding Darcs