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Blender 3D: Noob to Pro/Light a Silver Goblet

Note that the images are outdated.

Techniques
You should know how to:
 * Perform actions discussed previously in the tutorial.

This section will recap or introduce:
 * Reflective material
 * Positioning camera and light
 * Editing the World colors

Objects in the Scene
Create the goblet discussed in Model a Silver Goblet or load it if previously made. If you haven't already made the goblet, feel free to try the tutorial using a sphere or something else instead and you will still get a good outcome. In Object Mode with NUM 7 view, add a plane mesh. Scale the plane to a very large size and make sure the goblet is sitting comfortably on top of it.

Select the camera and move it so that the goblet, and its reflection in the plane will be seen or else if you want. You can see the numerical location of the camera by bringing up the Transform Properties window by pressing NKEY in the viewport. In my example where 0,0,0 is the bottom center of the goblet, the camera is located at 27, -21, 19 XYZ with a rotation of 63.5, 0.62, 46.7.

Create a Sun with Shift+A → Lamp → Sun. And (in the lamp properties "Object Data") set "energy" to "0.5", and place it above the goblet. Move it at around 80 points on the Z-axis. It is very important that you place the lamp on the right spot cause it will give your goblet anon 100 times more true to nature when you will give your goblet a silver texture. You can try placing a point or another lamp but it's very difficult to get a realistic image then. If you choose a different lamp click on the World button in the "Properties" header (the section where you can edit the sky). Check the Environmental Lighting box. Set energy to "0.800".

The rendering of this scene yields:

Old Picture.

Adding the Atmosphere
In Object Mode, select the goblet and go to the "Material Properties". If no material is linked to the goblet, add new material. Rename the material 'cup' or something similar. The area of interest is the Mirror window. Highlighted below are the mirror options we'll be playing with. Press the Mirror button to make the material act like a mirror and reflect light.

Move the "Reflectivity" slide to 0.85 or type it in after LMB on the number. This is how reflective the surface will be. A low number of 0.00 means that it reflects little while a high number of 1.00 reflects everything.

Also change the Fresnel slide from 0.0 to 1.4. This will increase the power of the Fresnel function. What this means is the color of the material will be strong because the light source is taken into consideration. If the Fresnel wasn't used, the object would appear dark because the light source isn't directly calculated in the mirror. Also, change the color of the goblet to white. Using a light color will give your goblet an interesting patina if you so choose.

Next, select the plane and modify the material, add if it is not there. We want the plane to be dark and shiny. Set Diffuse and Specular to near black for the color. For reflectivity, turn on Mirror to about 0.15 Reflective and ignore Fresnel this time.

There is only one more thing to do before rendering the scene: change the world. Under the "Properties" Header is the "World" panel. Here you have Paper Sky, Blend Sky, and Real Sky buttons. There are also options for changing the color of the horizon (Horizon color), zenith (Zenith color), and ambient (Ambient color). We're interested in these two windows at the moment.

Using Real sky and Blend sky will affect the way the horizon and zenith interact. Experiment with them to see what they do in the preview. In this example, Real and Blend are turned on.

The Paper button works a little differently in that what you see in the preview will essentially be the background of your render. This effect is most noticeable when your camera is rotated. Despite the camera rotation, the preview would still be 'wallpapered' on the render.

For our world, set the color close to black for the horizon, zenith, and ambient.

That was the last step! Make sure the camera is in the right spot and render the scene. Here is the output of this example

Creating a metallic texture for the goblet:
The metallic look can be achieved by these steps:
 * 1) Materials > Diffuse. Set color Hex value to: C7C8CB or you can set it completely black for dark metal. Set intensity to "0.8".
 * 2) Materials > Specular. Set color to white(Hex: FFFFFF). Change Intensity to "1.000", left of the color-swatch, set the specular shader to CookTorr. Also change the Hardness to value around "16".
 * 3) Materials > Mirror. Make sure the Mirror check-box is checked. Set Reflectivity to 1.000 and color to white(Hex: FFFFFF). Make sure that under "Gloss" the "Amount" is set to "1.000".
 * 4) (not compulsory but it may be required) Use the texture from this earlier tutorial: Procedural Wood Texture on the planes that are below and behind the goblet as in the picture below. It will give you a much better contrast.

Notes:

Problem: When I render I see brown where I have used "Shift-E" and "G" and I followed everything. Answer: Please remember, the author did say play with the settings a bit, this tutorial should be used as a guide. We are learning how to use all the tools that Blender has to offer, that is the important thing. It is up to us to experiment more with the settings set forth in these tutorials. If the settings in these tutorials do not give us the same results, that is OK, we should be changing them anyway to express ourselves! Also remember, NEVER strive for PERFECTION, but ALWAYS strive for EXCELLENCE. Perfection only leads to frustration, and it is frustrating enough, at times, to learn something new. Have fun learning, I know I am.

Noob Question: I managed to get it looking like the first picture above. How do I get it to look like the second? Pro Answer: Change the reflection settings. a higher depth and a larger raymir value will make the goblet more "mirror" like as in the 2nd picture. the other settings should be left alone, or you can experiment with them to achieve the effect that you want. lighting is also important. the object that is to be reflected has to be illuminated as well as the object that is doing the illuminating. Different lights (don't use a hemi if you want it to be realistic) at different angles will give you a more realistic effect.

Noob Note: On the answer above, I didn't manage to do it with any of the things the pro said in the answer here, I found out that the key is to change the color of the material which is white (or close to white) in the upper picture. In the lower picture the color is set to black (or close to black). This eliminates the "un-metallic" whitish sheen that the goblet in the upper picture has. Noob Note: I don't know about those using lower versions but those using v2.5x have a choice of different shaders both for diffuse and specular colours. I strongly suggest that for the same object one should try playing around with the shaders. They can create different effects. for eg. here if you change the diffuse shader type to oren-nayar and the specular shader type to wardiso, the goblet will have a glossy, finished look.


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Principles of Economics/Perfect Competition

Perfect competition
There are generally four types of markets that economists analyze: The first one is the simplest and thus best suited to an introductory economics course; however, it is incredibly unrealistic; practically no industry operates under that system. However, it provides a variety of insights, and some industries, such as agriculture, come relatively close.
 * 1) Perfect competition
 * 2) Monopoly
 * 3) Monopolistic competition
 * 4) Oligopoly.

In perfect competition, the following are true:

 * All producers contribute insignificantly to the market. Their own singular production levels do not change the supply curve.
 * All producers are price takers. They cannot influence the market.
 * Producers may enter and exit the market freely -- in other words, no barriers to entry exist in the market.
 * Producers alter their quantity produced, and may enter or leave the market, to bring the market equilibrium point to the intersection between the demand and supply curve (you will learn why in the Microeconomics section).
 * The goods sold by producers are standardized, meaning that the goods sold cannot be distinguished from other goods.
 * There are a large amount of buyers and sellers within that market.
 * Each buyer and seller is well-informed about the market prices of a given good or service.

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


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The Computer Revolution/E commerce/Online Shopping

Online shopping becomes more popular into people’s daily life. Lots of people prefer online shopping to normal shopping. The advantages of online shopping as follow: First, online shopping is easy and convenient for people to pick up the products they want, using Internet, people just need to click the mouse to finish the whole shopping process. Secondly, its save time and money, they can easily find the right catalogs and the goods right away by using Internet search engine. So online shopping makes shopping easy and life become easy too.

Online Shopping Sites
The world is your oyster and if you want one, you can buy one online! Amazon.com enables users to shop from home with products being delivered to their door, one can even do their grocery shopping online.

Online Shopping Benefits
Online retailers have used new technology such a
 * 1) 360 - degree images: take a look at the entire product in a 2 dimensional round the world tour
 * 2) Order tracking: fun fact on this point - FEDEX packages are scanned an average of 15 to 20 times from the time is leaves the supplier to its final destination.  Share that one with your friends and family.
 * 3) Shop box/concierge: tracks your shopping history and recommends other products you might be interested (think of this as an online minion out to do your bidding!)

As consumers online shopping saves time and eliminates the need to go to the mall and walk around aimlessly and have strangers invade your personal space.

Online shopping removes the need to do price comparison by going store to store - much more effective. Not to mention saving the wear and tear on your car and the environment (you never have to start your car).

Shopping Cart Software;Shopping cart software is software that is used on an existing website that allows you to create a shopping cart of items you may want to purchase on a specific website. It allows customers to freely put items in their shopping cart that they may possibly want, while continuing to shop. When ready to check out, and complete your purchase, you are able to click on the shopping cart icon and remove items that you may not want to purchase or to review the items in your cart before paying for your purchases. Most websites include this software free of charge to help customers shop for multiple items and conveniently add on to their orders. This tool is very helpful when shopping online.

The Dangers of Shopping Online
It's just so easy to spend excessively online because online shopping is done by credit card or debit card. Cash never leaves your hands so you don't think about how much you're spending. Beware of e-mail phishers, website pharmers, website / computer crackers, spammers, and scammers, too.

It's also so easy to never leave home (read: laziness).

Payment Processing
Merchants open an e-commerce merchant account, also called Internet merchant account, in order to accept credit cards as a form of payment. Paypal, which is an online payment service, is also used to make transactions between a business and consumer. Digital wallets, also called e-wallets, give consumers a way of storing they payment information securely for e-commerce purchases.

Certain online stores also offer additional payment services that can be selected during checkout, such as Bill Me Later (a PayPal service) and eBillme. This option allows the shopper to defer their payment until after the checkout process is completed. This allows for greater convenience and security for the consumer since they don’t need their credit cards handy to pay and also do not need to give their credit card numbers to the online retailer. However, a credit check is required first and you must live in the United States and be of legal age. Many of these services also charge an interest rate which you should consider before selecting them. (Morley, Deborah, and Charles S. Parker. Understanding Computers: Today and Tomorrow. 13th ed. Boston: Course Technology/Cengage Learning, 2011. Print.)

Some online stores offer the option to save data like payment information, shipping details and preferences in a digital wallet, also known as an e-wallet. Some e-wallets are offered directly through the store's website, meaning when the customer goes to check out their data is already stored from their last purchase. This makes the purchase easier and quicker for the customer. There are also programs available to download this as a standalone service through your mobile phone. When purchasing from an online store, the app autocompletes the required data so the user doesn’t have to. E-wallets are typically encrypted to keep data safe and password protected to avoid fraudulent use.

Another option for people to be able to shop online without having to worry about hackers getting their credit card numbers is having a virtual account number. These numbers are basically disposable credit card numbers that can be used by the customers to buy things online and the charge will actually go onto their real credit card. Some virtual credit card numbers can be used multiple times but most are good for just one transaction. Since the number only has a one time use, if a hacker were to intercept it, they would not be able to use it to make other purchases.

Morley, Deborah, and Charles S. Parker. Understanding Computers: Today and Tomorrow. 13th ed.

Digital Gift Certificates / Gift Cards

Digital gift certificates /Gift cards (e-gift cards) have become the new method of payment for online shopping. It is a very safe and convenient methods of payment. Digital gift certificate and cards are similar to the paper or plastic form used today except they are electronic forms. Many different companies offer digital certificates or cards, you can purchase them and send them via e-mail them to a recipient. The recipient will be able to redeem the certificate through online shopping of the website in the certificate is issued from. The gift certificates / cards can range from 5 to 500 dollars depending on the store your purchasing the certificate from.


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The Computer Revolution/Communication/Telecommunication

Telecommunications provide a means to communicate information, such as text, images, data, audio and video over long distances.

Telemedicine
Telemedicine provides interactive healthcare by utilizing the ability of computer networks to transmit medical information from one site to another via electronic communication in order to help improve patients' health status when traditional face-to-face consultations aren't an option. It assists patients who do not have access to certain care, and doctors from around the world can help or inform the existing physician in the area to that certain care. It can be a very helpful in an emergency case. Patients don’t have to wait for specialists to get an opinion and treatment. They can get immediate attention and treatment without any delay. It can help to save thousands of lives. In rural areas people are dying every day because they don’t get the right treatment at the right time. It is a cost effective alternative. People can’t visit the specialist because of their high fees and long waiting for appointment. They can get treatment through video conferencing. It is a two way communications between the patient and the physician or specialist. If the doctor is out of town for some reason the patient can still get treated through video- conferencing Also it makes patients feel more comfortable with nurses and can ask questions when need about any health concerns. Most often telemedicine allows patients to "visit" their physician live to receive immediate attention or to take medical images to be sent and analyzed by a physician. A few of the most common services include specialist referrals, patient consultations, remote patient monitoring as well as it facilitates medical education. This form of medicine is useful for patients and physicians living in rural communities or in remote locations where the nearest health clinic is hundreds of miles away. Telemedicine allows doctors or physicians to do video conferencing to communicate remotely and can discuss any situations they have about surgeries, medicine, and even previous patients that need transferring. A doctor can introduce his fellow physician about a new patient, if they have troubles with them, they can communicate the needs of the patients and what they could do to be better. Doctors can do diagnosing of patients who are in different areas of the world where they do not have time to visit. For example doctors can send pictures or vital statistics to the physicians located at that area to help them out. Health Information Technology and telemedicine is vastly expanding and will definitely a prominent factor in the field of medicine. Telesurgery-is another great example of telemedicine. Surgeons use the robot to perform surgeries; they control the robot over the internet or another network. Normally it is a physician who controls the robot instead of the robot being controlled by itself. Telesurgery gives the doctors a huge advantage because robots can zoom into an area where the naked eye cannot see. It can better locate a disease or virus, can distinguish between a good or bad cell. This form of robot-assisted surgery is typically more precise, results in smaller incisions, and allows patients to recover faster, then after surgery done by the human surgeon. The reason it helps a patient recover faster is because robots are less prone to get infection. It helps out patients as well because surgeons can now do less cutting or drilling to arrive to its destined area. For example pg.265 ( do not have to break a rib cage to access the heart). This type of telemedicine has a great potential in future. Especially for astronauts, who may need medical assistance while exploring the space (trip to Mars and back takes approximately three years or more), during those three years an astronaut could get sick or injured and would need assistance from the Telesurgery to get better. Soldiers injured in war zones, and for many other individuals who live in rural or undeveloped areas. Even to this date, physicians and astronauts have been practicing using telesurgery underwater so they can perfect it and be ready to do telesurgery in pace. The use of robot –assisted units will without a doubt become necessary in the future, and will give surgeons and physicians the ability to perform surgeries in locations with limited or impossible access. ''Reference: 13th Edition “Understanding Computers: Today and Tomorrow”-Deborah Morley, Charles S. Parker. Chapter 7, pg. 264.''

E Commerce Live Support
Many current business are now offering online chat support. You can visit a certain website, i.e. NewEgg or Dell, if you are just browsing or looking to purchase a specific product. You usually find a pop up window asking if you have any questions someone is live to type with. The online support is usually limited by certain hours or availability of personnel. The live support feature can be most useful to possibly find stocked items, answer general questions about services or product, or help process an order if you encounter any problems. Afterwards, depending on sites, you can have a transcript of the chat emailed to you for reference in the future or if any verification numbers might have been issued during.


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The Computer Revolution/Software/OS

The Operating System
The Operating System (OS) is the most important software in any computing device that is intended to interact with users (these include running applications from different creator than that of the OS). The OS is often a more complex System Software (SS), that is the most basic type of software that is required for a machine to operate, that often is even referred as Firmware (extremely reduced interaction with others than the creators, the firm).

Operating systems are much more prevalent than most people suspect. Most machines will be sold with some form of basic operative systems, some will bring it in installed form other will have it pre-loaded into read only memory (ROM). They requires it to function and so It is one of the most important software pieces on your computer. Without an operating system installed your computer becomes basically useless.

The operating system manages the hardware systems and software systems for your computer. It hides in the background of computer systems performing the small basic tasks that most people are unaware of, to translate applications code into instructions that the hardware can process.. There are some major tasks that most are aware of that the computer performs. These tasks include: Booting up the computer, organizing files, performing tasks (for example, reading from the hard drive), logging in, and managing security (firewall, permissions, etc.).

Today they exist not only in laptops or desktops, but in a wide variety of other devices. Operating systems have extreme versatility, especially with today's technologies. They also have large scalability, which means that operating systems can be simplified greatly or have features even the programmers may not be aware of. Operating systems are now used on routers, PDAs (Personal Digital Assistants), mobile phones, as well as a multitude of other computers including laundry machines and refrigerators. This does make sense as the computer in a typical modern cell phone is now more powerful than a desktop computer from 20 years ago. It also allows for customization of cellphones such as individualized rings and wallpapers.

The operating system interacts with the user in a form that can be understood by the user as it translates in computer form what is being entered by the user. This form can be text based or graphics based. For example, when you connect a device to your computer a pop up will come up on the taskbar explaining to the user what it is doing (installing the driver necessary to use the connected device). During the boot process the key component of the operating system called the kernel is loaded into memory. Unlike other components, the kernel is stored in the memory until the computer is turned off. The operating system can also configure and communicate with peripheral devices by installing the necessary device drivers needed to use that particular device.

The operating system controls the resources (memory, disk space) and makes them available as needed while you are using the computer. Also places in order which tasks need to be carried out. Storing files/documents in a specific location which can be fetched at a later time when needed. The operating system specific files are by default stored in its own folder (Windows Folder), and any applications which are installed their files will be stored the Program Files folder by default. Although there are default folders, users can create their own folders and name them accordingly to better organize. Each folder can hold multiple folders/files. File extensions should not be modified by the user as the operating system uses that information to open the file with the selected program. If the extension is modified the operating system will not know which program to use to open the specific file as a result the file will be corrupted and may not open.

The operating system has many security options to protect your computer from unauthorized users. Regular password that only you would know or using your finger print to log in. Another option would be setting up multiple accounts and making you the administrator on the computer while others would be standard users. Administrator users would have the ability to do anything on the computer, while standard users would be restricted from certain actions such as uninstalling/installing programs or modifying any settings.

The operating system has the ability to multitask, run multiple programs at once. The CPU is actually multitasking, going between different programs as it can only perform one task at a time. Multi-threading is the ability to perform multiple tasks within one particular program similar to multitasking which can perform between multiple programs. Both multiprocessing and parallel processing use multiple CPUs to perform tasks on your computer. Multiprocessing, each CPU performs on a different task than the other CPU. Parallel processing, multiple CPUs work on multiple tasks to speed up the process. Multiprocessing is used on most computers.

The operating system works to manage the memory being used by your computer by sending memory to programs being used and later retrieves it once the program is closed. Users can control memory use by closing programs which aren’t being used. Virtual memory is another way to enhance processing efficiency. Programs and data communicate between RAM and virtual memory as RAM is needed the information is copied to virtual memory and deleted from RAM. The process between RAM and virtual memory will continue until the program/data is complete. Using virtual memory can slower the process but it allows more memory use than what is available. To speed up processing on your computer, operating systems use a process called buffering and spooling. Buffering is space in the RAM or hard drive which stores the input and output. Spooling retrieves that information when needed. This will speed up processing as this particular task is not holding up the CPU from performing other tasks as it waits for one to complete.

Parker, D. M. (2011). Understanding Computers: Today and Tomorrow. Boston, MA: Course Technology. Cengage Learning.

Turning on
When booting up a computer there must be a basic operating system. There are multiple operating systems available for consumers to choose from; starting with the most common on desktop PCs, Windows, to common server operating systems, such as Linux. Windows is made to be user friendly, even those who know little about computers can easily master the basic commands. Linux comes in many different forms, some of them easy to use, and some of them meant more for those who are already aware of how computers operate, with complex codes and hard to use commands. The boot up information is usually stored in memory called ROM.

When the computer is booting up, several things will occur. First, the core of the operating system (known as the kernel) will be loaded into the computer memory. Then the computer identifies the hardware devices that are connected to the computer to confirm that all of the hardware devices are connected properly. Finally, there may be a login process or a security program launched via an instant message or login screen. These options can be customized by the user through the Windows Task Manager.

Parker, D. M. (2011). Understanding Computers: Today and Tomorrow. Boston, MA: Course Technology. Cengage Learning.

Basic functions
a major part of most operating systems, The file system, manages your files. It takes your files and puts them safely on your hard drive. It does the same function as you taking your papers and storing them in a filing cabinet until you need them next.

In addition to booting the computer, file management, and security, the operating system is also responsible for configuring devices. This is carried out with the plug and play feature, where devices become installed and accessed as soon as they are plugged into the computer, with the help of a driver, which is a small program that tells the operating system how to communicate with a specific device. Other responsibilities include communication with the user and managing and monitoring the computer’s resources. In a desktop computer, these resources are the processor, memory, disk space, etc. On a mobile phone, the resources include the screen, keypad, address book, battery, network connection, etc. The operating system’s overall goal is to provide a solid way for applications to work with the hardware.

Command Line Interface (CLI)

The CLI is non-graphical interface and uses typed commands only to perform. Although not as widely used as the GUI, the CLI can be used to accomplish many of the same feats - for those equipped with such programming skills. Through a CLI, one can encrypt files, create directories, navigate through directories, etc.

In Windows, the CLI used is called the Command Prompt. In Fedora, it is called the Terminal.

Graphical User Interface (GUI)
The GUI (pronounced gooey) is a visual interface; convenient and preferred by most users, because of its simplicity and appeal to the eye. By performing simple, graphical tasks such as clicking on an icon, dragging a folder, or right-clicking files and navigating through choices, files can be opened, moved, renamed, saved, and so forth.

Modern computer operating systems often provide a desktop graphical user interface ("GUI") for displaying various graphical objects. Some examples of graphical objects include windows, taskbars, docks, menus and various icons for representing documents, folders and applications. If the GUI is touch sensitive, then a stylus or one or more fingers may be used to interact with the desktop. A desktop GUI could be two-dimensional ("2D") or three-dimensional ("3D").

A 3D GUI is being developed and will allow mobile devices like mobile phones and tablet pcs to work with proximity sensor arrays and is being develop to respond to hovering gestures. Modern mobile devices typically include a variety of onboard sensors for sensing the orientation of the mobile device with respect to a reference coordinate frame. For example, a graphics processor on the mobile device could display a GUI in landscape mode or portrait mode based on the orientation of the mobile device. Due to the limited size of the typical display of a mobile device, a 3D GUI could be difficult to navigate using conventional means, such as a finger or stylus. For example, to view different perspectives of the 3D GUI, two hands are often needed: one hand to hold the mobile device and the other hand to manipulate the GUI into a new 3D perspective.

The 3D GUI display environment for mobile device will use orientation data from one or more onboard sensors to automatically determine and display a perspective projection of the 3D display environment based on the orientation data without the user physically interacting with (e.g., touching) the display. In some implementations, the display environment could be changed based on gestures made a distance above a touch sensitive display that incorporates proximity sensor arrays.

Security
Most, as not to say all, software has 'holes' in their programming, operating systems are no exception. But in these case vulnerabilities make it possible for people to 'attack' and/or use your computer with, or more commonly without, your knowledge.

Microsoft more than any other commercial OSs has a long list of documented weaknesses, some fixed some not because they have not been classified as critical. In considering why as OS has more detected security problems that others one has to take into account not only the quality of the software but also the number of users, especially those capable of reporting the issues, and the amount of attention an OS receives from those attempting to take advantage of it's weaknesses (this also has to do with the OS market-share the bigger the more attractive to exploit).

There are methods to close these holes. One of the newer abilities of well known operating systems is the ability to update the software either manually or automatically. These updates are normally downloaded to your computer from the internet and installed on your computer, basically changing the structure of the programming to make the operating system more secure. Another option is a program like Norton Antivirus. It is one of the most common, but there are many other choices the consumer can choose from. Antivirus software protects your computer from outside dangers, such as hackers, scammers, and viruses. A hacker can log onto your computer and see all your personal information, and possibly have access to even your banking information. Viruses are common in today's world, they come from receiving files, downloading things from the internet, or even visiting certain sites. Antivirus programs work with your operating system and constantly check everything the computer does for anything that might be a threat.

Digital Rights Management (DRM)
Digital Rights Management (DRM) is that part or type of technology which are used by hardware manufacturers, publishers, copyright holders, and individuals with the intent to control the use of digital content and devices after sale. In short to prevent piracy, it controls access through technology. Examples can be cited like, A company servers are programmed to block any forwarding of sensitive or restricted e-mail. E-book server is programmed to restrict copy of and printing of material as per the copyright holders contents. Software for DVDs limiting copies made. Thus restrictions, encryption etc, are few methods. DRM runs from the time floppy disks were there.

A DRM scheme operates on three levels Establishing a copyright for a piece of content. Managing the distribution of that copyrighted content. Restricting access via software once distributed on consumer level.

To accomplish this level of control, a DRM program has to effectively define and describe three entities- The user. The content. The usage rights. This it does by describing the relationship between them.

Graphical User Interface (GUI) V.S. Command Line Interface (CLI)
The command line and graphical user interface are two different ways a user can communicate instructions to the computer. For example, you can launch an application through the command line by typing in the command (path to where the program is installed) to open the application. Graphical user interface allows the user to physically search for the program via mouse click to open the application.

Although both methods are used today, GUI is the more common method used as it is much easier to grasp and people who are new to computers would find it extremely difficult to use the CLI method. With the GUI method it is much easier as you only have to learn how to point and click the mouse. With CLI it would be much difficult as you would have to memorize the path at which your file is located along with the different commands to open a file or launch an application. GUI is also a better way to go if you will be multitasking (using more than one program at a time) it is much easier to navigate to different windows using GUI. CLI does not offer an easy way to view multiple open applications or documents.

One good advantage about CLI is Scripting. CLI allows the user to use the command line to create what is called a script, which allows you to run a program without clicking through menus to find the program and run it. This is good for applications that should be run often say at a certain time. Although there are advantages and disadvantages to either option, it all depends on how good you are with the computer and if you have the patience to memorize all the commands and paths.

[http://www.computerhope.com/issues/ch000619.htm

Turning off
When you turn off your computer it writes any unsaved information to the hard disk. It will remember how your computer last looked and will reload that image next time you turn on your computer.

Operating System Classifications
Operating systems for personal computers are usually can be divided in several categories, in relation to a dedicated purpose, use or configuration.

On the personal computer most operating systems, are intended to be installed to a single computer and often, even if not restricted, will serve a single user. Today operating systems are subdivided into subcategories, such as desktop operating system, for mid and upper range machines and lighter versions for portables or legacy systems.

The server operating system is conceived to be installed as a network server, as to give several users access to its resources across a network. A server will often have no local users.

A network operating system, rests inside a server and serves to boot several client machines as its own personal operating system, often these client machines will not have any data storage device locally and will share the resources of the server machine.

There are also other factors that serve to distinguish operating systems, for instance the guarantees they provide in security or speed, for instance a real-time operating system will be dedicated to rapid processing of critical events, other relations can be formed about the structure of the OS, it can be monolithic or modular.

There are several types of Operating Systems which can be categorized. Multi-user operating systems are those in which one or more user(s) can run one or more program(s) at the same time. A Multiprocessing OS can allow one or more program(s) to run on more than one CPU. Most multiprocessing operating systems will run on single-processor machines, but it will be slower than a normal OS running on the same machine. Multitasking OS's allow more than one program to be running at the same time. Multithreading allows for different parts of the same program to be running concurrently. And finally, Real Time operating systems have an instant (as fast as possible) response to input. Most modern operating systems are a combination of several of the above types.

Mobile operating systems
Mobile Operating Systems or Mobile OS have surged in popularity in recent years. With the development of so many mobile devices such as smartphones and tablets the need for high functioning mobile operating systems is a must.

Several companies, for example Microsoft, which provide personal or server network operating systems also offer mobile versions of their operating systems Windows CE, in fact most of last core changes to the Windows have been made in reducing its system footprint, MS hope is that Windows 8 with a specific packaging will be able to work as a Mobile Operating System. On the other hand some companies have developed strictly mobile operating systems (iPhone OS/Blackberry OS/Android).

Since the first release of the iPhone in June of 2007, Apple has been breaking records with their releases of the iPhone. It is not just the fun features of the phone, but the software that it runs on that makes it so revolutionary. iPhone OS is based on Apple's OS X operating system. It supports multi-touch input, and has thousands of applications exclusively created for the system itself. The versions since iOS 6 have voice command technology, where by simply talking to the phone, you can search on the latest version of Safari, find your way around on Bing driven GPS system, or call and text by voice command.

It seems that at as mobile device technology continues to gain in popularity and diversity, the mobile OS will continue to advance as well. Mobile technology has now infiltrated multiple areas of society from smartphones to IPADs used in classrooms and without mobile operating systems that would not be possible. To the consumer the demand of hardware vendors of a lighter operating system has been extremely positive, the path of optimizing resource utilization has been increasing in importance and the need to make the Operative Systems portable across different hardware platforms, alleviates the technological stronghold that has permitted some firms to dominate the hardware and Operative Systems fields for decades.

Cloud computing
Many of the newer mobile device operating systems are taking advantage of the new meme "cloud computing". Cloud computing is really an mix of Internet technologies, storage, processing and social participation that is used as an off-site virtual service to gather,store and process information and allow you to share the information across machines to other persons. For example, let’s say you own an iPad, iPhone, and Mac computer. You schedule an appointment and put the appointment into the calendar application on your phone.

Cloud computing is in itself not an innovation, what has changed is the ease of access to the Internet, cost of storage (and improvement on storage technologies). It improved on usability of what previously would require some technical skill for instance to mount your own WEB and/or file server and incur in its operational costs. Those improvements became cumulative while you previous would then have to either repeat the input into your iPad and Mac, or you would have to manually sync all the devices with your computer. Now, using cloud computing, that synchronization of devices happens automatically whenever you are connected to Wi-Fi!

This of course has several implications, that are being exploited by corporations, that are not only willing to mine personal information from users of those services but will take the opportunity to control not only your data but your access to it.

GNU-Linux
GNU-Linux was developed by Linus Torvalds back in September 1991 using system tools and libraries originated in the GNU Project, initiated in 1983 by Richard Stallman. Since then, with help from around the world, Linux has become one of the world's most widely used operating systems.

The main difference between operating systems such as Windows and Mac compared to Linux is that both Windows and Mac are proprietary system, meaning that they have restrictions on them regarding usage and copying them. Whereas Linux is free software available for all to use, modify, and redistribute as they see fit.

Due to the nature of freeware there are literally hundreds of Linux distributions or versions, called Distros, available to users. These Distros vary greatly, some examples being hardware requirements, ease of use, stability, and appearance. When selecting a Distro, the idea is to find the one that meets as many of your needs as possible and is setup in your ideal fashion. After selecting the Distro that suits you best, you can finish customizing the operating system to make it truly unique to the user. Although all Distros are fully customizable they do have varying levels of technical competency requirements. A Distro such as Arch Linux that you install from scratch using a command line is not for a beginner compared to a Distro such as Linux Mint that is easy to install, has a GUI, and is packaged with application software common to many users.

Because of Linux's little to no cost, Linux is often found in micro-controllers or embedded computers such as PDAs, and cell phones. Linux is considered a unique operation system because it gives users the ability to customize it to a particular application. Linux is widely available over the Internet as a free download. It is available for both personal and server use and uses a much wider range of applications than Windows. Linux has a wide range of compatibility and many users are switching because they are finding it to be much more cost effective, and can get many different essential programs such as free or low cost office suites.

Commercial and proprietary Operating Systems
When you purchase your computer this software may not show up on the receipt but you have paid for it.

DOS
In August 1981, IBM introduced to the world the "Personal Computer” including the operating system called MS-DOS 1.0. Prior to having any issues with DOS it was suggested that users take the time to create a boot disk: 1.	Insert the blank floppy into the computer's drive.  2.	Click the Windows "Start" button and select "Run." 3.	In the text box that displays, enter "cmd" (= command) 4.	Press the "OK" button. This opens your Windows command prompt. 5.	Enter "sys (= system) x:" into the command prompt. 6.	Press "Enter." 7.	Replace "x" with the drive letter for your floppy drive. It only takes a few seconds to copy the boot files to the disk. 8.	Reboot the machine with the disk in the drive.

With the very first use of computers, DOS, or Disk Operating Software was just about the only operating system used. It is very uncommon for computers to use DOS today because Graphical User Interfaces are much simpler to use for the average computer using person. This is because DOS uses a command line interface where the user inputs commands for the computer to process, instead of clicking on windows like many people do today. There are two types of DOS. Both were created by Microsoft and were used for IBM computers or IBM compatible computers. The two types are PC-DOS and MS-DOS.

UNIX
UNIX was developed in the 1960’s at AT&T Bell Laboratories for midrange servers. UNIX is a multiuse, multitasking operating system. Microcomputers, mainframes, and a diversity of other devices from different manufacturers can run UNIX. The flexibility gives UNIX a lead over competing operating systems. Although, UNIX is more expensive, requires a higher level of technical knowledge, and tends to be harder to install, maintain and upgrade.

OS X
Based off the UNIX operating System, Mac OS is seen in Apple computers and is very user friendly, including simple graphical user interfaces. Mac OS X Lion also make navigation more simple using new multi-touch gestures. Newer Mac OS can support dual 64-bit processors which is advantageous while multi-tasking. Mac OS X also has the capability of running Windows via BootCamp, so on restart, you have the option(by holding the "alt" key while the screen flashes white) of booting into Windows or Mac OS X. This function is not very well reciprocated by Windows at all. People have tried installing Mac OS X on Windows, commonly referred to as "Hackintosh's", albeit with loss of functionality and stability.

The term Hackintosh has become ever more popular as Apple starts to move to general purpose hardware technology that is easily accessible to anyone. 2005-2020 Mac hardware builds of Apple use the Intel i5/i7 second generation processor to offer the best performance with their operating system. The Apple software license of the Mac OS X does not allow it to be used on a computer that is not "Apple-branded. The hackintosh, a collaborative Kernel hacking project, works as the newer processors are now more compatible with the Mac OS X software and can be tweaked to work with current Gigabyte motherboards and second generation processors. Using information from tonymacx86.com you use iBoot and Multibeast to load kernels and drivers and install Mac OS X (Mac OS X Lion, with Mountain Lion in the works as of February 2012) on compatible hardware. The biggest attraction is the options outside of the processor and motherboard that could be easily changed to each persons style or interests.

.

Microsoft Windows
Microsoft Windows is the most popular desktop operating system, and has been for many years. As with technology in general, the Windows operating system has evolved over the years.

Microsoft has developed a wide range of Windows operating systems. In 1985, the original version of Windows was introduced as Windows 1.0, and later followed by Windows 3, which had several versions, such as 3.0, 3.1, and 3.11. They simply enhanced the DOS operating system, making it more user friendly, this trend continued with Windows 95 and 98.

The creation of the Windows NT and then the Windows 2000, Windows XP Professional, XP Home, Windows Vista and many more, were a large technological advance. While the first versions of Windows were simply add-ons to DOS. Later versions did not depend on DOS.

Windows desktop came in the footsteps of other OSs and enabled the customization of the GUI. That included changing skins, mouse keys function and the style of desktop, colors and etc. Until the release of Windows 98, free OS alternatives were not as attractive, by maintaining the GUI elements static across versions users feel comfortable and easily adapted to new releases. This was until Vista, since then the GUI of Windows has been in constant change.

Windows Vista version of windows had several improvements over Windows XP, it still has it's downside. Windows Vista had the following new features:
 * 3D window viewing
 * Capable of using flash memory as RAM rather than adding memory to the motherboard
 * secure features than all previous windows versions
 * side bar to allow quick access to commonly used gadgets
 * Super-fetch feature.

The new Super-fetch feature knows what most commonly used programs/tasks are and keeps them in the memory to allow faster responsive times.

Windows Vista downsides:
 * The system requirements for Windows Vista are extremely high compared to previous windows versions and even other modern operating systems.
 * The integration of new forms of digital rights management (DRM), specifically the Protected Video Path (PVP).
 * Poor hardware driver support.
 * Legacy software incompatibility.
 * Concerns have been expressed that Windows may be experiencing software bloat.
 * Expensive compared to other modern operating systems.

Whether you should use Windows Vista largely depends on how you want to and need to use your computer.

The next operating system that Windows released was Windows 7. It was released in 2009. Windows 7 system requirements are about the same as Vista. Windows 7 was designed to start up and respond faster then Vista. It also focuses on making it more user friendly. An example of this you can drag taskbar buttons to have them the way you like it. Also, Windows 7 have a Device Stage. This was formed to make it easier to use and manage all your connected devices. Microsoft states Windows 7 runs well on netbooks, this was not always the case with Vista.

In 1995, Microsoft launched Windows 95, which was their first full-fledged operating system, and it was followed by Windows 98. Windows NT (New Technology) was the operating system developed for high-end workstations and servers. Following 98, was Windows ME (Millennium Edition) and Windows 2000, replaced Windows NT. These systems were followed by Windows XP, which replaced both Windows 98 and Windows 2000. Windows Vista replaced XP, and was the current version until 2009, when Windows 7 was released.

Windows 7 was available in four main editions and in 32-bit and 64-bit versions. The appearance is similar to Windows Vista but runs faster and is easier to use. It has many new features like rearranging taskbar buttons, pin locks on programs to the taskbar, arranging two windows side by side quickly and easily, or resizing windows to fill half of the screen easily.

iOS
iPhone OS: Every iPhone has used a different variation of the same operating system since Apple first launched them in June of 2007. The latest versions support multitasking, video calling, picture messaging, the ability to cut, copy, and paste text, in addition to other features other phones have adapted in order to remain competitive in the smartphone market. To make applications for the iPhone OS one would need to learn how to program in Objective-C and be familiar with the Cocoa API.

title: The Computer Revolution/Software/OS


text:
The Computer Revolution/Entertainment/Video players

Video is the constant stream of visual information. When a video is recorded, it is broken down into separate frames. Frames are projected at a rate of about 30 frames per second to keep the video looking continuous. Video data is often compacted. “Lifestreaming” is becoming a larger part of today’s society. Creating an online record of daily activities and submitting them on the Internet is a way for people to broadcast themselves.

Video player is that software applications used in computer system of entertainment purpose. Some of the popular ones are Realplayer, Windows media player. Video players can review movies, download movies from internet, DVD or CD burner, play music and ect. Video players let users feel more entertained while using a computer.

Windows Media Player This is an all purpose media player that plays audio and video files. Media Players are software programs for playing multimedia files, audio or video on your computer developed by Microsoft. Windows has various types of free downloadable devices you can choose from. You can create your own library of playlists by purchasing music through ITunes and transferring them to a cd. I like purchasing the music because you just buy the songs you really like. These playlists allow you to burn cd’s or watch dvd’s. You can also stream music on your computer (listening) while working on files or documents. I found that out this year when I wanted to listen to music but didn’t have a small radio or cd player. This is a nice feature and I don’t normally use media players. My husband has burned cd’s for our car cd player using this. But you have to be careful because of copyright laws, do not do this to sell music.

Quicktime
QuickTime is an Apple technology for handling video, sound, animation, graphics, text, and music. It is compatible with MAC and Windows users. QuickTime can also be described as a file format, an environment for media authoring and a suite of applications which include but are limited to the following:

QuickTime Player – is a free download from the Apple website which can be used for basic audio and video files. A number of features are disabled that would be present in the Pro version.

QuickTime Pro – is an upgrade to the QuickTime Player and can be purchased and can be used for flexible multimedia authoring. It also includes full-screen playback, editing clips through the cut, copy and paste functions, merging separate audio and video tracks and the options of cropping and rotation.


text:
User:Davidbspalding

Who
I've been a registered Wikipedia user since March, 2006. Web user/developer since 1994. Internet user since 1991. Home page here. Former freelance writer, public radio producer, technology mentor, U.S. Coast Guard avionics tech and aircrewman, musician, film student (USC). Strictly a Wikipedia newbie, but catching on fast.

I'm a San Francisco native, have lived and worked in the South many years, currently residing in Durham, NC.

What
I just registered here, so I don't know what to do yet. ;)

Et cetera
I've had my own domain, Korova.com for quite a while. I got rid of www.RadarLove.com when spam got out of hand, and picked up ChromeJob.com instead. Claims to fame? I've a few ... saved lives and intercepted airborne drug smugglers in the USCG (I was an avionics tech and flew in jets), reviewed music and film, produced an ambient music program for public radio, sysop'ed on CompuServe, wrote about cyberban legends, hoaxes and malware on the Internet before most people did,.... I'm also a contributor to Memory Alpha. (I'm an old, old school Trekkie.)

title: User:Davidbspalding


text:
User:Davidbspalding/sandbox

Behold my sandbox. Castle building starts here.
— David Spalding ta!k y@wp / Contribs

title: User:Davidbspalding/sandbox


text:
Social Ballroom Dancing/Tango/American

Torso, shoulders, and head
Both partners should try to keep their torso erect at all times. Imagine that you are resting on your hips. Your torso should be straight up at all times - do not arch your back or lean backwards. As should your head. Shoulders should be relaxed and loose. Keep your head straight up at all times, and looking slightly to the left of your partner. As to the position of your neck and head: imagine you are standing up against a wall. No matter where you move, that wall is still behind you, and you must not move your head in front of it or into it.

Arms
Your elbows should be up and to the side at all times.

Feet
In closed position, for both the lead and follow, the left and right foot should be locked together. The positioning of the feet depends upon the role.
 * lead
 * The left foot should be ahead of the right foot so that the heel of the left foot fits into the curvature of the right.

 * follow
 * The right foot should be ahead of the left foot so that the heel of the right foot fits into the curvature of the left.

Line of dance
Tango, like most other traveling ballroom dances, follows a large, oval-like path around the dance floor. Couples travel counterclockwise. Instead of always utilizing turns, a tango lead should apply a gradual curve to the couple's movement as necessary to follow line of dance. If you are just practicing a move, there is no need to apply this curve - it is only important when one is dancing around the dance floor.

Basic
lead:
 * 1) left forward (slow)
 * 2) right forward (slow)
 * 3) left forward (quick)
 * 4) right side (quick)
 * 5) tap close (no weight change) (slow).

follow:
 * 1) right back (slow)
 * 2) left back (slow)
 * 3) right back (quick)
 * 4) left side (quick)
 * 5) tap close (no weight change) (slow).

First Promenade
lead: after tap close (where left foot is free), turn both torsos to face lead's left, walk forward two steps as if beginning a basic, on the third turn follower in front of you, then, now aligned with your partner, forward side-close.

Corté
Lead: left foot back, replace right, forward, close.

title: Social Ballroom Dancing/Tango/American


text:
User talk:202.85.42.140

You are blanking a large amount of content without reason. If you do not stop, you will be blocked as a vandal. --Whiteknight (talk) (projects) 04:45, 4 December 2006 (UTC)

This message is regarding the page Cookbook:Strong Noodles. Please refrain from adding nonsense to Wikibooks. It is considered vandalism. If you would like to experiment, use the sandbox. --Az1568 07:46, 20 December 2006 (UTC)

title: User talk:202.85.42.140


text:
Neapolitan/501 Neapolitan verbs/sapé

sapé

 * to know (something)

1. Innecativo
 * a. presente
 * {| class="wikitable"

 * align="left"|io
 * align="left", bgcolor="#c9c8e9"|saccio
 * align="left"|tu
 * align="left", bgcolor="#c9c8e9"|saje
 * align="left"|isso/essa
 * align="left", bgcolor="#c9c8e9"|sape
 * align="left"|isso/essa
 * align="left", bgcolor="#c9c8e9"|sape

 * align="left"|nuje
 * align="left", bgcolor="#c9c8e9"|sapimmo
 * align="left"|vuje
 * align="left", bgcolor="#c9c8e9"|sapite
 * align="left"|isse/lloro
 * align="left", bgcolor="#c9c8e9"|sapeno
 * }
 * align="left"|isse/lloro
 * align="left", bgcolor="#c9c8e9"|sapeno
 * }

Past participle
 * saputo

title: Neapolitan/501 Neapolitan verbs/sapé


text:
Wikijunior:How Things Work/Metal detector

Who invented it?
In the late 1800s, many scientists and engineers used their knowledge of electricity to try to invent a machine which would find metal. It could be used to find valuable stones, so it could make a lot of money. The German physicist Heinrich Wilhelm Dove invented the basics for the metal detector, which was made into a metal detector a hundred years later. Early machines were sloppy and used a lot of battery power, and worked for a very short distance. Better versions of the metal detector started to be created in the 1930s.

A scientist named Gerhard Fischer wanted to find a way to know where you are and what direction you are going. It is similar to today's GPS (Global Positioning System). It worked really well, but Dr. Fischer noticed that there were problems in places where the ground had rocks with ore in them (ore is rock that contains metal). He found out that this could be used to find metal. In 1937, he got the first patent for a metal detector. His designs were used as mine detectors during the Second World War (mines are bombs that are hidden underground). The metal detectors were heavy, had vacuum tubes, and needed separate battery packs. After the war, there were plenty of leftover mine detectors on the market. They were bought up by treasure hunters who used them for fun and for gaining money. The hobby of metal detecting had been born.

How does it get power?
Usually by battery.

How does it work?
The transmitter coil and the receiver coil.

What does it do?
It can be used to search for valuable stones and artefacts. It can also be used to find mines and to use as security systems. For example, if someone is carrying a metal gun or bomb a metal detector can find it (although if the bomb is sensitive to magnetism it could cause the bomb to explode instead.) Some kinds of metal detectors can tell what kind of metal is being found and how far away it is.

How does it vary?
Metal detectors use one of three technologies:

Very low frequency (VLF) Pulse induction (PI) Beat-frequency oscillation (BFO)

How has it changed the world?
In countries where there have been wars, there are still many mines buried in the ground which continue to injure people. In these regions, metal detectors are the best way to solve the problem and make the areas safe again. They have also been used to make important historical finds.

Fun Facts
-The Scottish physicist, Alexander Graham Bell, the inventor of the telephone, used a metal detector to try to find a bullet that was in the back of American President James Garfield in 1881.


text:
Talk:Demystifying Depression/Suicide

"bear in mind that you have no clue whatsoever of what you are talking about."

Well, that shut me up. I thought I was totally right until you made all those unsupported statements. --Monk 05:59, 4 December 2006 (UTC)

title: Talk:Demystifying Depression/Suicide


text:
C++ Programming/Programming Languages/C++/Code/Style Conventions/Documentation

Document your code
There are a number of good reasons to document your code, and a number of aspects of it that can be documented. Documentation provides you with a shortcut for obtaining an overview of the system or for understanding the code that provides a particular feature.

Why?
The purpose of comments is to explain and clarify the source code to anyone examining it (or just as a reminder to yourself). Good commenting conventions are essential to any non-trivial program so that a person reading the code can understand what it is expected to do and to make it easy to follow on the rest of the code. In the next topics some of the most How? and When? rules to use comments will be listed for you.

Documentation of programming is essential when programming not just in C++, but in any programming language. Many companies have moved away from the idea of "hero programmers" (i.e., one programmer who codes for the entire company) to a concept of groups of programmers working in a team. Many times programmers will only be working on small parts of a larger project. In this particular case, documentation is essential because:
 * Other programmers may be tasked to develop your project;
 * Your finished project may be submitted to editors to assemble your code into other projects;
 * A person other than you may be required to read, understand, and present your code.

Even if you are not programming for a living or for a company, documentation of your code is still essential. Though many programs can be completed in a few hours, more complex programs can take longer time to complete (days, weeks, etc.). In this case, documentation is essential because:
 * You may not be able to work on your project in one session;
 * It provides a reference to what was changed the last time you programmed;
 * It allows you to record why you made the decisions you did, including why you chose not to explore certain solutions;
 * It can provide a place to document known limitations and bugs (for the latter a defect tracking system may be the appropriate place for documentation);
 * It allows easy searching and referencing within the program (from a non-technical stance);
 * It is considered to be good programming practice.

For the appropriate audience
Comments should be written for the appropriate audience. When writing code to be read by those who are in the initial stages of learning a new programming language, it can be helpful to include a lot of comments about what the code does. For "production" code, written to be read by professionals, it is considered unhelpful and counterproductive to include comments which say things that are already clear in the code. Some from the Extreme Programming community say that excessive commenting is indicative of code smell -- which is not to say that comments are bad, but that they are often a clue that code would benefit from refactoring. Adding comments as an alternative to writing understandable code is considered poor practice.

What?
What needs to be documented in a program/source code can be divided into what is documented before the specific program execution (that is before "main") and what is executed ("what is in main").

Documentation before program execution:
 * Programmer information and license information (if applicable)
 * User defined function declarations
 * Interfaces
 * Context
 * Relevant standards/specifications
 * Algorithm steps
 * How to convert the source code into executable file(s) (perhaps by using make)

Documentation for code inside main:
 * Statements, Loops, and Cases
 * Public and Private Sectors within Classes
 * Algorithms used
 * Unusual features of the implementation
 * Reasons why other choices have been avoided
 * User defined function implementation

If used carelessly comments can make source code hard to read and maintain and may be even unnecessary if the code is self-explanatory -- but remember that what seems self-explanatory today may not seem the same six months or six years from now.

Document decisions
Comments should document decisions. At every point where you had a choice of what to do place a comment describing which choice you made and why. Archaeologists will find this the most useful information.

Comment layout
Each part of the project should at least have a single comment layout, and it would be better yet to have the complete project share the same layout if possible.

How?
Documentation can be done within the source code itself through the use of comments (as seen above) in a language understandable to the intended audience. It is good practice to do it in English as the C++ language is itself English based and English being the current lingua franca of international business, science, technology and aviation, you will ensure support for the broadest audience possible.

Comments are useful in documenting portions of an algorithm to be executed, explaining function calls and variable names, or providing reasons as to why a specific choice or method was used. Block comments are used as follows:

Alternately, line comments can be used as follows:

An example of a full program using comments as documentation is:

It should be noted that while comments are useful for in-program documentation, it is also a good idea to have an external form of documentation separate from the source code as well, but remember to think first on how the source will be distributed before making references to external information on the code comments.

Commenting code is also no substitute for well-planned and meaningful variable, function, and class names. This is often called "self-documenting code," as it is easy to see from a carefully chosen and descriptive name what the variable, function, or class is meant to do. To illustrate this point, note the relatively equal simplicity with which the following two ways of documenting code, despite the use of comments in the first and their absence in the second, are understood. The first style is often encountered in very old C source by people who understood well what they were doing and had no doubt anyone else might not comprehend it. The second style is more "human-friendly" and while much easier to read is nevertheless not as frequently encountered.

Both functions perform the same task, however the second has such practical names chosen for the function and the variables that its purpose is clear even without comments. As the complexity of the code increases, well-chosen naming schemes increase vastly in importance.

Regardless of what method is preferred, comments in code are helpful, save time (and headaches), and ensure that both the author and others understand the layout and purpose of the program fully.

Automatic documentation
Various tools are available to help with documenting C++ code; Literate Programming is a whole school of thought on how to approach this, but a very effective tool is Doxygen (also supports several languages), it can even use hand written comments in order to generate more than the bare structure of the code, bringing Javadoc-like documentation comments to C++ and can generate documentation in HTML, PDF and other formats.

Comments should tell a story
Consider your comments a story describing the system. Expect your comments to be extracted by a robot and formed into a manual page. Class comments are one part of the story, method signature comments are another part of the story, method arguments another part, and method implementation yet another part. All these parts should weave together and inform someone else at another point of time just exactly what you did and why.

You should refrain from using comments to do ASCII art or pseudo-code (some programmers attempt to explain their code with an ASCII-art flowchart). If you want to flowchart or otherwise model your design there are tools that will do a better job at it using standardized methods. See for example: UML.
 * Do not use comments for flowcharts or pseudo-code


text:
User talk:Unforgettableid

Please do not edit the main page template without looking around first. It isn't something that is appropriate for much editing -- Herby talk thyme 08:57, 4 December 2006 (UTC)
 * Nope! -- Herby talk thyme 08:59, 4 December 2006 (UTC)
 * I guess I see "changing the main page" as being something that maybe should be run past a few others. If it were me I'd post in the staff lounge and ask for views there.  That said I do realise that you can do it and I will not interfere again - I'm at work , so can't talk much, really just watching RC - cheers -- Herby  talk thyme 09:08, 4 December 2006 (UTC)
 * Contribution appreciated - don't let me put you off, just urging some caution -- Herby talk thyme 09:13, 4 December 2006 (UTC)

 * Good joke - other RC patrollers!! -- Herby talk thyme 09:16, 4 December 2006 (UTC)

Welcome
Hello and welcome to Wikibooks!

Here are some tips to help you get started:
 * You should sign your name on Talk and vote pages using four tildes, like this: ~~~~.
 * Remember to conduct any editing experiments in the sandbox.
 * If you're a Wikipedian, see Wikibooks for Wikipedians for a primer on how things work here (it's a little different).
 * If you want to base your work here on materials from Wikipedia, please use WB:RFI to bring the material over in compliance with the GFDL.
 * If you're an instructor and plan on using wikibooks for a class project, see Guidelines for class projects
 * Please say hello at the Staff Lounge with any questions or ideas.
 * Eventually, you might want to read the Manual of Style and Policies and Guidelines.
 * Please take a look at Naming policy before starting a new book.
 * Remember to maintain a Neutral point of view.
 * Explore, be bold in editing pages, and have fun!

You will find more resources in Community Portal. If you want to ask a question, visit the Study help desk, the Staff lounge, IRC channel or ask me personally on my talk page.

Good luck! -- Herby talk thyme 08:58, 4 December 2006 (UTC)

BTW
You are completely correct about the cat on WW2 page in my view (I'd placed something on the editors page earlier but had no response - cheers -- Herby talk thyme 09:12, 4 December 2006 (UTC)
 * R U WP by any chance? -- Herby talk thyme 09:15, 4 December 2006 (UTC)
 * Yes, I'm w:user:unforgettableid Unforgettableid 09:15, 4 December 2006 (UTC)
 * Waaaay different pace/approach here. It's a nice place but it takes a while to get to.  The link in the welcome on the wb for wp is quite useful.  Enjoy the "sabbatical"  - cheers -- Herby  talk thyme 09:21, 4 December 2006 (UTC)

Template:Main Page introduction
I'd hate to add to Herbythyme's revertions, but I think it might be inapproperiate to change the message without discussion with other members of the community. Its part of the defintion of what Wikibooks is and I believe might be considered a major change. Also I object to your linking to Wikipedia, because Wikibooks is not Wikipedia. We have our own help pages, abit they need major work, that would IMO be better suited for linking to. --dark lama  15:23, 4 December 2006 (UTC)

title: User talk:Unforgettableid


text:
User talk:131.155.113.39

Hi!
Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally.

I noticed you corrected a typo. Thank you. Cheers, Unforgettableid 09:29, 4 December 2006 (UTC)

title: User talk:131.155.113.39


text:
User talk:193.210.145.13

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.

-- Herby talk thyme 10:40, 4 December 2006 (UTC)

title: User talk:193.210.145.13


text:
Talk:Python Programming/PyQt4

The text on the original web page says: "This document is published under the GNU Free Documentation License."

UI file?
This is a good tutorial, I am glad that you updated it for qt4.

Can you also attach the UI file you used? I am having trouble trying to convert the qt3 one. pyuic4 keeps complaining that it doesn't support "Q3Support widgets" even after updating the file in QT designer (version 4). -Terrible Tim 23:29, 1 January 2007 (UTC)

Indent of python code.
Is the leading space in the source code example for some reason. It is indented with one space, which makes it annoying to copy paste to Python (IndentationError).

title: Talk:Python Programming/PyQt4


text:
Cookbook:Knoephla (Small Flour Dumplings)

Knoephla are dumplings commonly used in knoephla soup, a popular dish in the American Midwest.

Ingredients

 * 2 cups (500 ml) all-purpose flour
 * 1 tsp (5 ml) baking powder
 * 1 egg
 * ½ cup (250 ml) milk or water

Procedure

 * 1) In a mixing bowl, combine the flour, baking powder, egg, and then the milk or water. Mix to form a firm dough that is not sticky. Add a bit more flour if needed to keep dough from being sticky or a bit more liquid if too dry.
 * 2) Roll pieces of dough between the hands to the length of a pencil (6 in / 15 cm). Snip off small pieces with a knife or scissors.
 * 3) Use the knoephla as specified in your given recipe.


text:
Cookbook:Knoephla Soup

Knoephla soup is a common dish served in the U.S. states of North Dakota and Minnesota. This recipe is from Preacherman777's contribution on English Wikipedia.

Ingredients

 * Knoephla yielded from 2 cups of flour
 * 2 qt (2 L) water
 * 2 tbsp (30 ml) chicken soup base
 * 1 cup (250 ml) onion, chopped
 * 1 cup (250 ml) butter
 * 2 lb (900 g) potatoes, cubed
 * 1 cup (250 ml) heavy whipping cream
 * 1 tsp (5 ml) chopped parsley (optional)
 * Salt
 * Pepper

Procedure

 * 1) Melt the butter in a large soup kettle over medium heat. Add the add the onion, and sauté until onions are tender.
 * 2) Add the water and soup base. Bring to a rapid boil over high heat. Add the knoephla by dropping them into the boiling broth. Stir until they all float to the top, and cook until the dumplings are soft.
 * 3) Add the potatoes, then simmer over medium heat until dumplings and potatoes are done throughout.
 * 4) Remove from heat. Add the cream, then season with parsley as well as salt and pepper to taste.

Notes, tips, and variations

 * If you need to reheat the soup, use low heat so the cream doesn't curdle.

title: Cookbook:Knoephla Soup


text:
User talk:Alexwcovington~enwikibooks

Hello and welcome to Wikibooks!

Here are some tips to help you get started:
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You will find more resources in Community Portal. If you want to ask a question, visit the Study help desk, the Staff lounge, IRC channel or ask me personally on my talk page.

Good luck! -- Herby talk thyme 11:18, 4 December 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 Alexwcovington. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Alexwcovington~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 22:56, 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) 04:30, 19 April 2015 (UTC)

title: User talk:Alexwcovington~enwikibooks


text:
User:Alexwcovington~enwikibooks

See my user page on English Wikipedia.

title: User:Alexwcovington~enwikibooks


text:
Talk:Haskell/Alternative and MonadPlus

The diagram in the guard section
Pardon my ignorance, but shouldn't that tree under the 'guard' section look like this?

start |____________________________________________ ...   |                     |                    | x  1                     2                    3 |_______________ ... |_______________ ... |_______________ ...    |      |      |       |      |      |      |      |      | y  1      2      3       2      3      4      3      4      5 |___...|___...|___... |___...|___...|___...|___...|___...|___...   | | |  | | |  | | |   | | |  | | |  | | |  | | |  | | |  | | | z  1 2 3  2 3 4  3 4 5   2 3 4  3 4 5  4 5 6  3 4 5  4 5 6  5 6 7

 * It looks like you're right. Maybe we should see what DavidHouse thinks... I suppose after a while, we should just go ahead and replace that diagram -- Kowey 13:17, 6 December 2006 (UTC)

 * (I'm pretty sure) he's right -- Felix C. Stegerman 08:35, 10 June 2007 (UTC)

Also, the 'guard' section contains:

 * So the empty list produced by the call to  in the binding of   will cause   to be the empty list, and therefore   to be the empty list.

The way I see it, since  evaluates to   (the empty list),   is never called in (what evaluates to). Which means it should be (something like):

 * So the empty list produced by the call to  in the binding of   will cause   to be the empty list.  I.e.   evaluates to , which evaluates to  ).    is never called.

(feel free to rephrase that)

-- Felix C. Stegerman 09:08, 10 June 2007 (UTC)

 * To provide long overdue closure on this discussion: both the diagram here and the one in the original chapter are wrong, to the extent they do not reflect how  is actually calculated. A more appropriate diagram is now on that page. As for the   issue, I have rephrased that in the spirit of your suggestion. Thanks for highlighting the issue. --Duplode (discuss • contribs) 19:19, 20 November 2016 (UTC)

On the guard section diagram
Uhm, I was wondering maybe this sentence "we need a branch starting from the top for every choice of z, then a branch from each of these branches for every value of x, then from each of these, a branch for every value of y." has some problems? According to the scheme below, shouldn't we branch x first, then y then z?

Sqdcn (discuss • contribs) 13:45, 24 April 2016 (UTC)

 * The diagram was wrong -- not just due to the x/y/z issue, but also the numbering didn't match the  definition. The chapter was just rewritten, and this issue is now fixed. --Duplode (discuss • contribs) 18:17, 20 November 2016 (UTC)

title: Talk:Haskell/Alternative and MonadPlus


text:
Georgia Water/Policy/Local Ordinances

Stormwater Management

 * Model Ordinances for Stormwater Management for Metropolitan North Georgia Water Planning District (Atlanta area).

title: Georgia Water/Policy/Local Ordinances


text:
Xray Crystallography/Foundations

Wavelength
Why do we use X-rays to view molecules? X-rays are electromagnetic radiation just like visible light, but have a far shorter wavelength. X-rays have a wavelength of around 1Å ( 1 Angstrom is 1x10-10meters ) compared to 350-700nm for the visible light range. This shorter wavelength is useful because it allows the resolution of atomic detail, this is because you cannot see details of a size less than half of the wavelength you are using. However there is a downside to using short wavelengths, energy is inversely proportional to wavelength, this means X-ray photons are more damaging to the biological sample.

Energy
X-rays are part of the electromagnetic spectrum, with a magnetic and electric component to the wave. Since they have wave-particle duality, they can also be thought of as particulate in some cases, and wave-like in others. Electromagnetic radiation has an inverse relationship between wavelength and energy.

$$E = \frac{hc}{\lambda}$$

where E = Energy, h = Planck's constant, c = speed of light, λ = wavelength.

It is often convenient to convert wavelengths into energies, in the field of X-ray crystallography the most useful units is keV or kilo electron-Volts. A quick and simple conversion is;

$$E(keV) = \frac{12.4}{\lambda{}(\AA{})}$$

X-Ray Window
X-rays are in the section of the electromagnetic spectrum known as the X-ray window. This means that they are not absorbed by air or water. It also means that they can be very penetrating. Care should be taken around X-ray beams, never put your hand directly in the path of the beam. Lead can be used to stop X-rays. 'Soft' X-rays have a wavelength of around 2Å, these are absorbed readily by air and water and as such are not very penetrating. X-rays of wavelength shorter than 0.2Å are termed $$\gamma$$-rays and are very penetrating, but do not interact greatly with matter. This leaves a usable range of wavelengths from 0.5-1.6Å suitable for X-ray crystallography giving sufficient penetration of sample and enough interaction to have scattering.

Interactions
Of the X-rays incident on a crystal, only around 2% will interact, the rest will be collected by the beam stop. Of the 2% that interact with the crystal; 8% will interact by (elastic) coherent Thompson scattering giving the observed diffraction pattern, another 8% interacts through (inelastic) incoherent Compton scattering which gives rise to the background noise on the diffraction pattern, however, a worrying 84% interact through the photo-electric effect giving rise to radiation damage by the production of free radicals (Murray J and Rudiño-Piñera E, 2005).

Why Use Crystals
We use crystals because of the high power of the X-ray beam. X-ray beams are highly damaging especially to biological samples. By using crystals, the damage is distributed among the individual molecules, however the final image generated is a time and space averaged image of electron density for all the proteins in the unit cell.

Lenses
So why can't we just use an X-ray microscope?

The main problem with an X-ray microscope is that it is not possible to manufacture a lens capable of focusing X-rays. The refractive index of all materials to X-rays is close to 1. It is possible to use zone-plates which use diffraction rather than refraction to focus light to a wavelength of 50Å, but this is not suitable for high resolution work.

To overcome this problem we use a computer to do the work of the lens for us. In light microscopy the incident light is diffracted by the object onto the lens, the lens then takes the diffraction pattern and recombines the diffracted beams onto a focused spot generating the image. In X-ray crystallography, we are stuck with the diffraction image which can be recorded by either an image plate or a CCD, this is an image of Bragg peaks where planes within the crystal interfere constructively.

The only problem of this is that the phase information is lost. Diffraction image recording equipment can only measure the amplitude of the Bragg peak, not the phase information. The phase information can be thought of as the time of arrival of the incident wave or the depth through the unit cell.

Synchrotron Radiation
Synchrotron Radiation is one of the brightest lights on earth. It is the single most powerful tool available to X-ray crystallographers. It is made of X-ray beams generated in large machines called synchrotrons. These machines accelerate electrically charged particles, often electrons, to nearly the speed of light, then whip them around a huge, hollow metal ring. Synchrotrons were originally designed for use by high-energy physicists studying subatomic particles and cosmic phenomena. The largest component of each synchrotron is its electron storage ring. This ring is actually not a perfect circle, but a many-sided polygon. At each corner of the polygon, precisely aligned magnets bend the electron stream, forcing it to stay in the ring. Each time the electrons’ path is bent, they emit bursts of energy in the form of electromagnetic radiation. Because particles in a synchrotron are hurtling at nearly the speed of light, they emit intense radiation, including lots of high-energy X-rays.

[edit]

title: Xray Crystallography/Foundations


text:
User talk:Sasa.tomic

Hello and welcome to Wikibooks!

Here are some tips to help you get started:
 * You should sign your name on Talk and vote pages using four tildes, like this: ~~~~.
 * Remember to conduct any editing experiments in the sandbox.
 * If you're a Wikipedian, see Wikibooks for Wikipedians for a primer on how things work here (it's a little different).
 * If you want to base your work here on materials from Wikipedia, please use WB:RFI to bring the material over in compliance with the GFDL.
 * If you're an instructor and plan on using wikibooks for a class project, see Guidelines for class projects
 * Please say hello at the Staff Lounge with any questions or ideas.
 * Eventually, you might want to read the Manual of Style and Policies and Guidelines.
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 * Remember to maintain a Neutral point of view.
 * Explore, be bold in editing pages, and have fun!

You will find more resources in Community Portal. If you want to ask a question, visit the Study help desk, the Staff lounge, IRC channel or ask me personally on my talk page.

Good luck! -- Herby talk thyme 13:11, 4 December 2006 (UTC)

PyQt4
I've taken the liberty of moving this page to Python Programming/PyQt4 as it seems it should be part of this book rather than on its own. Let me know if I can help - regards -- Herby talk thyme 13:11, 4 December 2006 (UTC)

title: User talk:Sasa.tomic


text:
Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nf6/3. Nxe5

=Petrov Defence=

3. Nxe5
Black has to drive the white knight away before attacking.
 * The natural move /3...Nxe4/ is a bad move, containing a deadly trap and variations that put White into a superior position. After White plays 4. Qe2, Black loses a pawn after 4... d5 or 4... d6, and 4... Nf6?? is a blunder that loses a queen. 4... Qe7 is the best move after which Black will likely win back the pawn, but White retains a stable advantage larger than the main line.
 * /3...d6/ is the main line.
 * /3...Nc6/ the Stafford Gambit

=Theory table= .

'''1. e4 e5 2. Nf3 Nf6 3. Nxe5'''


text:
Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nf6/3. Nxe5/3...d6

= Petrov Defence =

White's choice is limited. The main line suggests to retreat knight by playing /4. Nf3/. However, 4. Nd3!? has been tried, though it is not as promising because it blocks the d pawn. 4. Nc4 may look like another unique idea, but according to computers it is only as effective as 4. Nd3 or even, worse than Nd3. It is been marked as ineffective by certain people, but it is another idea that is worth trying. On the positive side, no pawn is blocked, unlike in Nd3. The main issue with 4. Nc4 is that the knight is in the center of the board in an odd position and can't return to a natural development square, like f3 or c3. It will be chased around quite a bit. White can also try the Cochrane Gambit  /4. Nxf7/, a dangerous line for both players.

=Theory table= .

'''1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6'''


text:
TeX/includeonly

Synopsis
\includeonly{filename1, filename2 ...}

Description
When writing a large document, it is sometimes useful to work on selected sections of the document. In LaTeX, the command

\includeonly{filename,filename2,...}

will result in only the files specified between the brackets being compiled (note no spaces in the list and without file name extension '.tex'). It is paired with the \include command: the \includeonly command should only be placed in the preamble of the LaTeX file, whilst the \include commands should only be placed in the main body. If \includeonly is not specified in the preamble, LaTeX will assume that all \include commands should be evaluated.

The syntax for an \include command is pretty simple: \include{filename}

Notice that the following are not equivalent: \include{filename.tex} does nothing while \include{filename} works. Note, however, that \input{filename.tex} and \input{filename} are in fact equivalent - but as explained below \input is not what is needed here)

but note \include differs slightly from \input:

1. it may only be used after the \begin{document} command

2. it acts like \clearpage \input{} \clearpage

3. if filename does not exist, it will not cause a crash

4. a file added via \include may not contain another \include (i.e., \include is not recursive). However, \input commands are acceptable within included files.

http://www-hermes.desy.de/latex/ltx-165.html

title: TeX/includeonly


text:
User talk:Redback~enwikibooks

Your contributions are appreciated - however merely adding external links is less so. Wikibooks needs standalone content for readers so contributions of that sort would be good -- Herby talk thyme 16:28, 4 December 2006 (UTC)

Please do not add inappropriate external links to Wikibooks. Wikibooks is intended to be read without the need for external reference and requires content rather than external links particularly those which are for advertising or promotion. Inappropriate links may include (but are not limited to) links to personal web sites, links to web sites with which you are affiliated, and links that exist to attract visitors to a web site or promote a product. If you feel the link should be added to the article, then please discuss it on the article's talk page rather than re-adding it. See the welcome page to learn more about Wikibooks. Thank you. -- Herby talk thyme 09:52, 5 December 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 Redback. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Redback~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 23:40, 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) 05:25, 19 April 2015 (UTC)

title: User talk:Redback~enwikibooks