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JavaScript/Primitive data types

Primitive types use a fixed format; some can contain only a limited number of certain values. In contrast, objects are more complex, especially including methods and properties.

With the exception of  and , primitive types have a corresponding object wrapper with data type specific methods. Therefore you will find on this page descriptions of some methods.

String
String is a datatype to hold text of arbitrary length. String variables are created by assigning a string literal to them. String literals can be enclosed in  or.

If your string literal contains a  or , you can use the other one as the outer delimiter, or you escape them with a.

If your string literal is computed out of some fixed text plus some dynamic parts, you can use the template literal technique. Here, the literal is enclosed in backticks  and contains variables and expressions.

The  operator concatenates two strings, e.g.  . Additionally, there are a lot of methods for strings.

Hint: JavaScript doesn't have something like a 'character' or 'byte' data type.

Properties and methods for strings
We show some methods which are often used. For a complete list, please refer to MDN.

length
is a property, not a method. Hence there are no parenthesizes. It returns the length of the string as a whole number.

concat(text)
The method returns a string where 'text' is appended to the original string.

indexOf(searchText)
The method returns the position of the first occurrence of 'searchText', starting with 0. If 'searchText' cannot be found, -1 is returned. The method is case sensitive.

lastIndexOf(searchText)
The method returns the position of the last occurrence of 'searchText'. If 'searchText' cannot be found, -1 is returned. The method is case sensitive.

replace(text, newtext)
The method returns a string where 'text' is replaced by 'NewText' on the original string. Only the first occurrence is replaced. The method is case sensitive.

As you can see, the  method only returns the new content and does not modify the origin string in 'foo'.

slice(start [, end])
The method returns a substring beginning at the 'start' position.

When the 'end' is provided, they are extracted up to, but not including the end position.

allows extracting text referenced from the end of the string by using negative indexing.

Unlike, the slice method never swaps the 'start' and 'end' positions. If the 'start' is after the 'end',  will attempt to extract the content as presented, but will most likely provide unexpected results.

substr(start [, number of characters])
The method is deprecated. Use  or   instead.

substring(start [, end])
The method extracts a substring starting at the 'start' position.

When the 'end' is provided, they are extracted up to, but not including the end position.

always works from left to right. If the 'start' position is larger than the 'end' position,  will swap the values; although sometimes useful, this is not always what you want; different behavior is provided by #|slice.

toLowerCase
The method returns the current string in lower case.

toUpperCase
The method returns the current string in upper case.

Number
Number is one of the two numeric types (the other one is BigInt). Number stores integer values as well as floating point values in a unified 64-bit format defined by IEEE 754. That means, that JavaScript doesn't have different data types for integers and float like some other languages.

The possible range for such values is approximate -10300 to +10300 with different precision depending on the distance to 0.

In the range from -(253 − 1) to +253 − 1 there is no uncertainness for integer operations. 253 = 9,007,199,254,740,992 which is a little smaller than 1016.

For Number the usual arithmetic operators ('power' is  and 'modulo' is  ), comparison operators (,  , ...), and bitwise operators are available.

In opposite to some other languages, the division of two whole numbers can result in a number with decimal places, e.g..

Properties and methods for numbers
Working with numbers is supported by many properties and methods. Internally, they are implemented at different areas:
 * The built-in object  provides properties that represent common mathematical constants like π or e. Syntax:   (no parenthesis)
 * The build-in object  provides common mathematical functions like sin or log. Syntax:   (with parenthesis)
 * The object  provides properties that characterize the implementation of the data type number, like MAX_VALUE or NEGATIVE_INFINITY. Syntax:   (no parenthesis)
 * The object  provides static methods that check the relation between numbers and other data types, e.g., isInteger or parseFloat. Syntax:   (with parenthesis)
 * The object  provides instance methods that act on concrete number values or variables, e.g., toExponential or toFixed. Syntax:   (with parenthesis)

We show some properties and methods which are often used. For a complete list, please refer to MDN Math and MDN Numbers.

Properties
Most commonly used constants:
 * Returns the constant e.
 * Returns the constant pi.
 * Returns the natural logarithm of 10.
 * Returns the natural logarithm of 2.
 * Returns the square root of 2.

Math.ceil(number)
Returns the smallest integer greater than the number passed as an argument.

Math.floor(number)
Returns the greatest integer less than the number passed as an argument.

Math.round(number)
Returns the closest integer to the number passed as an argument.

Math.max(number_1, number_2)
Returns the higher number from the two numbers passed as arguments.

Math.min(number_1, number_2)
Returns the lower number from the two numbers passed as arguments.

Math.random
Generates a pseudo-random number between 0 and 1.

Number.parseFloat(string)
The two methods  and   convert strings into numbers. They scan the given string from left to right. When they recognize a character distinct from 0 - 9, they finish scanning and return the converted numbers read so far (parseFloat accepts the decimal point). If the first character is distinct from 0 - 9, they return Math.NaN, meaning Not a Number.

Hint: It's not necessary to specify 'Number.' in the source code.

BigInt
BigInt is a data type that represents integers of arbitrary length. Hence, it's a variable-length format (conceptually) delimited only by the available RAM.

BigInts are created either by adding a 'n' to the end of an integer literal or by using the  function.

BigInt supports the arithmetic operators, comparison operators, and most of the bitwise operators.

Boolean
Boolean variables can contain one of two possible values,  or. JavaScript represents  by either a Boolean false, the number 0, NaN, an empty string, or the built-in types undefined or null. Any other values are treated as.

Undefined
Variables that have just been declared but not initialized with any value have the data type undefined.

Null
In JavaScript, null is marked as one of the primitive values, because its behavior is seemingly primitive. However, when using the  operator, it returns "object". This is considered a bug, but one which cannot be fixed because it will break too many scripts.

Symbol
Symbol represents a unique identifier. Symbols may have a descriptor that is given as a string to its constructor.

Symbols are used as keys in objects (embedded in ) to guarantee uniqueness.

Exercises

 * ... are available on another page (click here).

title: JavaScript/Primitive data types


text: JavaScript/Other data types

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

title: JavaScript/Other data types


text:
JavaScript/Variables/Exercises

Topic: Declaration and Initialization

{Which line(s) lead to an error? - Line 2 - Line 3 + Line 4 - Line 5 - None of the above
 * type="[]"}

{Which line(s) lead to an error? - Line 2 - Line 3 - Line 4 + Line 5 - None of the above
 * type="[]"}

{Which line(s) lead to an error? - Line 2 - Line 3 - Line 4 + None of the above
 * type="[]"}

{Which line(s) lead to an error? - Line 2 - Line 3 + Line 2 - Line 3 - Line 4 - None of the above
 * type="[]"}
 * The alert shows that the variable  does have a value of   does have a value of   does have a value of
 * type="[]"}

{Which line(s) lead to an error? - Line 2 - Line 3 - Line 4 - Line 5 + Line 6 - None of the above
 * type="[]"}

 * Be creative
 * 1) Explain to your colleague why programs need variables.
 * 2) Create a code snippet that defines a variable within a block scope. Access this variable within the block scope and outside of the block scope.
 * 3) Discuss with your colleague the advantages and disadvantages of using the global context.

title: JavaScript/Variables/Exercises


text:
JavaScript/Primitive data types/Exercises

Topic: Primitive Data Types

1. Write a script with the following steps (the 'power'-operator is '**'):
 * Compute the value of 250. Store it in the variable.
 * Compute the value of 250 + 1. Store it in the variable.
 * Compare  with  . Are they equal?

2. Repeat the previous exercise with 260 instead of 250.

3. Repeat the previous exercise with 1000 instead of 1.

4. Discuss the results of exercises 1 - 3 with your colleague.

5. Write a script with the following steps:
 * Compute the value of one divided by three. Store the result in the variable.
 * Show.
 * Multiply  by three and store the result in.
 * Show . Which value do you expect?

6. Write a script that shows that 5 and 5.0 are identical values.

7. Write a script that
 * asks the user how old he is:
 * always returns a string. To perform the calculation, it's necessary to convert the answer to number,  ,
 * if his answer is a numeric value, show how often his heart has beaten since his birth (approximately once per second)
 * else, give a message like "Sorry. We need a numeric value to perform the computation."

8. Create a HTML page for the previous exercise and embed the solution into the HTML. You can refer to this example.

{9. What shows the 'alert' statement? - 3.14 - float + number - undefined - None of the above
 * type=""}


text:
JavaScript/Objects/Exercises

Topic: Objects

1. Be creative.
 * Create an object which describes some of your physical or mental attributes.
 * Show the object with the  command.
 * Show only the most important attribute of this object with the  command.
 * Add another property to the object. Show the complete object again.
 * Delete the least important attribute. Show the complete object again.

2. Articles of a warehouse.
 * Create two objects  and   which characterize shoes. Use the literal notation.
 * Create two other objects  and   which characterize shirts. First, create empty objects. Then, add attributes to the objects.
 * Create an object  and add all 4 objects to it.
 * Show the price of the 4.-th product out of the warehouse object.

title: JavaScript/Objects/Exercises


text:
Popular Music/The Weeknd/Save Your Tears/Views Over Time

The following table shows the cumulative view count for "Save Your Tears" as of 12:00 noon EDT of each calendar day. This table covers all dates May 8, 2022 — October 3, 2022.


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User talk:12wedfcvghyu78Io90

Welcome, 12wedfcvghyu78Io90!

If you have any questions, you can ask in the assistance reading room or possibly contact me personally.--Xania   talk 05:05, 10 November 2022 (UTC)

Unblocked 2
A

12wedfcvghyu78Io90 (discuss • contribs) 01:14, 4 August 2023 (UTC)

title: User talk:12wedfcvghyu78Io90


text:
Talk:Chipmunk Basic pocketManual

Sprite Commands Don't Work
Running chipmunk Version 1.368.22 (1.368.2202) on Mac 12.6.1

The sprite movement commands don't work

sprite 1 down 100 results in a missing comma error.

title: Talk:Chipmunk Basic pocketManual


text:
Wikijunior:Raspberry Pi/Raspberry Pi Turtle Stars

Turtle is a programming language that is used to draw artwork using a turtle and a series of commands. We are using the Python module which allows you to draw pictures using Turtle commands.

Draw a star
First we're going to write a program to draw a star:

Now change the program so that it uses a function:

Now change the function to draw different size stars:

Now, change the function so that we can draw stars of different sizes and colours:

Have fun creating many stars of various sizes and colours!

Turtle API
This is a full list of the functions provided by the Turtle Python module: https://docs.python.org/3/library/turtle.html

Move and draw
|   |   |    |    |    |   |    |

Tell Turtle's state
|

Drawing state
|  |    |   |    |

Visibility
|   |   v

Appearance
|

Using events
|

Special Turtle methods
|

Window control
|   |

Using screen events
|

Settings and special methods
|


text:
User talk:120.149.65.60

--SHB2000 (discuss • contribs) 12:11, 10 November 2022 (UTC)

title: User talk:120.149.65.60


text:
Geometry Dash/Leaderboard Top 1 History

Geometry Dash is a 2-D game developed for iOS, Android, and Steam. This is the history of the Top 1's on the global leaderboard.

Before we get to the main point, let's go over some background. Update 1.3 of Geometry Dash introduced stars, attainable through beating the official levels that the developer, RobTop made, or by playing rated levels people created. He also introduced a global leaderboard. People could obtain stars and go to the top of the leaderboard. Note that this will not cover the stars that the players had, but it will cover how long the players stayed at the top, and how they would basically battle for first place on the leaderboard. It will also only cover the first place, and not the other places behind it. Also some dates couldn't be listed here.

From January 26 2015 - February 24, 2015, LunarSimg and the top player "3xotiC" would switch over and over again.

This list is uncomplete. You can help by fixing/adding information.

title: Geometry Dash/Leaderboard Top 1 History


text:
Lentis/The Yellow Vests Movement

Introduction
In September 2018, the French government announced a tax increase on gasoline and diesel. This increase was defended by French president Emmanuel Macron as being necessary to decrease the nation's dependence on fossil fuels, however, many citizens, including climate activists, were outraged at yet another cost of living increase. Much of the middle class felt that they were not getting anything in return for the constant tax hikes with this newest fuel tax increase being just the latest example. Macron's reasoning for the tax increase felt hollow to many given his reputation for being the "President of the Rich" stemming from his lowering of taxes that mostly affect the upper class elite. The tax announcement exacerbated the existing unrest and provoked a series of protests taking place every Saturday mainly from November 2018 to February 2019.

Initial protestor profile
The initial public outcry in response to the fuel tax increase came from mainly people unable to afford living within cities yielding them lengthy commutes by car. These people felt they would feel the brunt of the tax increase despite having way to forgo their vehicles due to lack of public transportation in suburban and rural communities. These people viewed this as an affront to the already-vulnerable working class. Protestors organized through social media and had no leadership.

Expanded protestor profile
Other subsets of French citizens quickly joined the initial group of protestors. A representative of the IFOP polling organization described the new protestors as "people who are too rich to receive welfare benefits but not rich enough to live well. Not the poorest but just above that." These are people who run small businesses or work difficult, low-paying jobs and are frustrated seeing their tax money going to other people while they make barely enough to get by.

Fuel prices
France introduced a plan in 2014 to continually tax fossil fuels to disincentive their use and promote alternative energy sources. Carbon taxes have been imposed in a number of European countries and are viewed by activists as being an essential method to fight climate change. Before the announced increase, France's tax rate of 64% on unleaded and 59% on diesel led to the 6th highest diesel price and 7th highest petrol price out of European countries. Although the fuel tax increase was far from the first in Europe or France, the continual increases in cost of living the working class saw imposed upon them heightened already mounting frustrations. The general sentiment is that the fuel tax was "the drop of water that makes the vase overflow."

Emmanuel Macron
Even before the newly-proposed fuel tax, Macron proved to be a divisive president. Despite beating his opponent handily in the presidential election in May 2017, by August Macron's approval rating was just 36 percent. Macron, a former investment banker, was mired by multiple controversies including not keeping promises regarding defense spending, suggesting he would give his wife a paid position in the government, and causing much of the public to view him as overly elitist. Leading up to the yellow vest movement protests, Macron's approval rating as president fell even lower to 25 percent according to a poll by IFOP.

Organization
The yellow vest movement was leaderless and grew largely though Facebook and other social media platforms.

Yellow vest symbolism
Protestors taking part in the movement have become recognizable by the bright yellow vests they adorn, also called gilets jaunes. In France, motorists are required by law to keep these Day-Glo vests in their vehicles. Protestors decided to wear the vests for their parallel to the new fuel tax; both the vests and the fuel tax were imposed upon the citizens by the government. The vests are also ideal as they by nature draw attention to their wearers. The yellow vests brought cohesion to an otherwise disorganized movement.

Protestor demands
The protest started over repealing diesel taxes, which turned into "an uprising against President Emanuel Macron's policies and become the biggest challenge against his presidency." Many wanted a higher minimum wage, a dissolution of the National assembly, and new elections to be held.

The protests
An online petition to lower fuel taxes that reached over 300,000 signatures by October 2018 is believed to be the beginning of the movement. Protestors began organizing online, with the idea for a national blockade event being posted on Facebook. The blockages as well as the high visibility vests served as low-tech methods to make their cause known and easily identifiable to the public. Freight trucks were one target of the blockades. In response, L'organisation des PME du Transport Routier (OTRE) sent an open letter to Prime Minister Edouard Phillipe highlighting their frustration with the scenario.

After two months of protest, President Macron launched "the Grand Débat, a national listening exercise that involved thousands of meetings around France, plus an online register where people could list their grievances and demands." By creating a public forum for discussion, Macron hoped to reduce the violence and calm the public by showing that he was listening. This exercise lasted about two months, then protests still continued, but in organized streets rather than rural areas. The protestor profiles also changed, "from being largely rural and apolitical, to younger city-dwellers who [have] previously been involved in politics".

Violence
Occasionally the protests became violent. Protestors smashed windows, vandalized monuments, and set cars and trashcans on fire. In late 2018, French police began changing the manner in which they engaged with protestors. Moving away from a hands-off, passive approach, police began to actively suppress the protests. In late 2018 thousands of arrests in connection to the protests were made, hundreds of protestors were injured, and multiple deaths occurred. The estimated total damage was $3.4 million.

Violence also took the form of antisemitism. With instances such as a black swastika being painted on portraits of an Auschwitz survivor, a Jewish cemetery being defaced and antisemitic remarks being hurled at a Jewish person. With unorganized protest comes the risk of people using the platform to spread their own unrelated hateful beliefs.

Public Perception of the Movement
Because of the popularity from social media, the protestors gained a lot of attention and support with Harris Interactive estimating 72% of France supporting the movement as of December 4, 2018. There was a decline in popular support as time passed to about 50% mostly due to violence caused by a subset of the protestors, "not just against property and police but against journalist and each other."

Political results
On December 4, 2018, the fuel tax was suspended. Prime Minister Édouard Philippe stated that "No tax warrants putting the unity of the nation in danger." In addition to the tax suspension, the government promised to delay increasing electricity costs and new vehicle inspection protocols while also increasing the minimum wage by 3%. Despite the concessions, a spokesmen for the movement expressed the protestors continued dissatisfaction saying, "We're not satisfied, because the French have been struggling for years now." Another spokesman stated, "There's no guarantee [the fuel tax] won't be back in six months ... There will be more demonstrations." Another reaction was blunt saying, "We're being taken for idiots." On December 5, 2018, the Prime Minister stated that both he and Macron supported dropping the tax from the budget completely. In April 2019, after the Grand Débat, Macron made more changes such as income tax cuts largely targeted at middle-earners, end of the year bonuses for low paid workers, higher pensions for low earners etc.

Climate change implications
Vanessa Williamson stated that, "The protests are wrongly being interpreted as evidence that "big government" policies to address climate change are politically infeasible." If solutions for climate change increase economic inequality, then those solutions are "ethically dubious" and "politically impractical." The tax hikes in France benefited the wealthy people. President Macron "had substantially reduced union power in the workplace and drastically cut taxes on the rich." Since tax cuts went to the rich people, it makes sense for people with low or middle income to protest against fuel tax increases. The issue in the yellow vest movement was mainly economic inequality, it does not mean the protestors were against climate change. Based on a discourse analysis of yellow vest resistance against carbon taxes, a climate transition should happen "through more consultation, by making the rich and not the poor to pay for transition." Robert Stavins, a professor at Harvard, suggests that implicit policies such as a "cap-and-trade mechanism" would face less public opposition than an explicit tax.

Evaluation
The yellow vests movement demonstrated the effectiveness that low-tech approaches can have. The yellow vests served to give their movement a symbol, allowing the disorganized to appear as one cohesive movement. With this disorganized movement, however, came the ability for people to hijack the platform the yellow vests movement had created, to spread both violence and hate, unrelated to the initial purpose of the movement. Perhaps this case serves as a cautionary tale. In the absence of leadership, the movement can begin to divert and take on additional, often unrelated meaning.

Future work
For future additions to this page, the following topics can be included: the first anniversary of the yellow vest movement where about 28,600 people protested across France, attempts to link yellow vests protests to other causes, including Extinction Rebellion, the pension reform protests in late 2019 and early 2020", and "the anti health pass demonstrations" in late 2021. Future work could also look into which interest or political groups claimed that the yellow vests movement represented their ideology and perhaps attempted to take some control over the movement.

title: Lentis/The Yellow Vests Movement


text:
Chess Opening Theory/1. e4/1...c6/2. b3

Caro-Kann Defence, Euwe Attack
White's response to the Caro-Kann is a fianchetto of the dark-squared bishop. This move is rarely played today, but was used with success by World Champion Max Euwe, who won against Richard Reti in 1920.

Black will almost always continue with the usual 2...d5.

title: Chess Opening Theory/1. e4/1...c6/2. b3


text:
User:Mn00ch

Mn00ch is a Wikipedian located in the United States.

title: User:Mn00ch


text:
User talk:Akp4ujp

Welcome, Akp4ujp!

If you have any questions, you can ask in the assistance reading room or possibly contact me personally.

--Xania   talk 01:43, 11 November 2022 (UTC)

title: User talk:Akp4ujp


text:
User talk:47.4.85.174

Warning
Xania   talk 01:48, 11 November 2022 (UTC)

title: User talk:47.4.85.174


text: User:Heliodorus the Samnite/sandbox

title: User:Heliodorus the Samnite/sandbox


text:
Cookbook:Somen

Somen are a variety of thin Japanese wheat noodles.

Characteristics
Somen noodles are very thin, pulled noodles made from wheat flour. They are about 1 mm thick and round, with a pale color and very mild flavor. A variety called tamago somen contains egg in the dough.

Production
Somen are traditionally made by kneading wheat flour, water, and salt to make a dough. After a rest period, the dough is rolled and stretched into ropes. These ropes are very carefully twisted and stretched very thin (about 1–1.3 mm thick). The finished noodles are then dried, cut, and packaged. Some varieties of somen are aged for up to 2–3 years.

Selection and storage
The dried noodles have a very long shelf life at room temperature, lasting at least 1 year in a cool, dry location.

Use
Before use, somen are briefly simmered in a large volume of water, then drained and placed in an ice bath to stop the cooking process. The cooked noodles are then used in the final preparation. One popular way to eat somen is cold with a soy-based dipping sauce called tsuyu, with garnishes on the side such as scallions, sesame, and seaweed. The noodles can also be served hot in a broth, or added to salads and stir-fries.

In the special dish nagashi somen, cooked somen noodles flow down a stream of water and are picked out by diners to eat.

Substitution
If you can't find either somen or somyeon (the Korean version), then another variety of very thin wheat noodles (e.g. angel hair) will make an acceptable substitute. Be sure to check the salt content of the noodles and adjust as necessary.

title: Cookbook:Somen


text:
Cookbook:Cumian

Cumian, also called Shanghai noodles, are a Chinese variety of thick wheat noodle.

Characteristics
The noodles, like udon, are wheat flour-based are thick, with a chewy and springy texture.

Use
The noodles are often used in northern Chinese soups and stir fries.

Substitution
Udon noodles can be used as a substitute in some applications.

title: Cookbook:Cumian


text:
Digital Circuits/Counters

Counters stores number of time a particular event or process as occurred often in relation to a clock pulse.

title: Digital Circuits/Counters


text:
User:Nancyperry.me

I’m an independent writer from Ca, US, with vast experience in writing.

title: User:Nancyperry.me


text:
Cookbook:Jjolmyeon Noodle

Jjolmyeon (쫄면 – literally "chewy noodles") are a variety of wheat-based Korean noodle.

Characteristics
The noodles are made with a mixture of wheat flour, wheat starch, and water. This dough is heated and extruded to form the noodles, and this process makes thick noodles with a very springy and chewy texture.

Use
Jjolmyeon noodles tend to be sold either on their own or with accompanying condiments used to make the noodle dish of the same name. They are typically fresh, and it is best to store them in the freezer until use.

To cook jjolmyeon, separate the noodles from each other and cook them in plenty of boiling water, stirring occasionally. Avoid overcooking, which will make them mushy. Drain and rinse the noodles to remove excess starch.

title: Cookbook:Jjolmyeon Noodle


text:
Circuit Idea/Using Analogies to Understand Circuits

What are analogies?
We begin learning from the day we are born. In this way, in the early years of our childhood, we accumulate a knowledge of life for visible (mechanical, hydraulic, pneumatic, social, etc.) phenomena of our world. But this world is arranged so interesting that apparently different phenomena obey the same laws; they are analogous.

Then, why do not we use associations as educational mainstays that convey the common knowledge about visible worldly phenomena to invisible abstract electric phenomena? Thus they will look familiar, elementary and accessible. This is so because we, human beings, begin understanding new unfamiliar things when we begin discerning something familiar inside them. We just consider new complex things as composed by a few simpler well-known components. Here are some examples of applying analogies.

Closed loop fluid analogies
One of the earliest human representations of Ohm's elementary electric circuit is the fluid analogy (also known as "fish tank") - under the action of pressure P in a closed pipeline, a fluid current with a flow rate I meets along its path resistance R. The voltage source in this analogy is represented by a compressor that maintains a constant pressure (just like those that power pneumatic instruments).

Using a more complex fluid analogy, we can illustrate the circuit of a passive voltage summer that we use as a subtractor and comparator in op-amp circuits with negative feedback. If it is two-input, we include two pressure sources.

Their effects are summed at the common point and so the pressure on the load is the sum of the input pressures. If this is an analogy of a resistor subtractor (comparator), the positive input voltage source V1 can be thought of as a compressor that pushes air and increases the pressure in the common point. The negative input source V2 is presented as a compressor that sucks the air and creates a vacuum at the point. Figuratively speaking, the two compressors "fight" with each other and if their pressures are related as their respective air resistances (P2/P1=R2/R1) the pressure at the common point is equal to zero. This phenomenon can be figuratively called a fluid virtual ground.

Open loop fluid analogies
In addition to being a compressor that maintains a constant pressure, a voltage source can also be represented as a cylindrical vessel (on the left) with a constant water column level.

In the analogy of a voltage subtractor, the positive input voltage source V1 will represent a vessel placed at the earth's surface (zero level) and the negative source V2 a vessel lowered below the ground surface. Under some conditions, the hydraulic pressure at the common point will again be equal to zero - this can be called hydraulic virtual ground.

Mechanical Analogies
One of the most popular mechanical analogies is Archimedes' lever, which in this example is operated simultaneously from both sides. When the equality h2/h1=l2/l1 is fulfilled, a virtual mechanical mass is obtained at the common point. If we stylize this analogy, we arrive at the more abstract geometric voltage diagram.

No less famous is the weight analogy - a mechanical scale, with the help of which two weights are compared. The balance pointer points to a virtual mechanical ground when the equality P2/P1=l1/l2 is satisfied.

"Live" analogies
To show the connection between an analogy and its corresponding circuit diagram, we can "live" the analogy on the monitor screenwith the help of a computer. For this purpose, we can connect the circuit under test by means of an analog-to-digital periphery to a personal computer operating under the control of an appropriate software. An analogy of the studied circuit will be displayed on the screen, which responds adequately to changes in the circuit and thus strengthens associations with it.

Web resources
Voltage causes current introduces the most elementary circuit building blocks (Flash movie; Ruffle Flash emulator needed)


text:
Cookbook:Glass Noodle

Glass noodles, also called cellophane noodles, are a general class of noodles made from vegetable starches. They should not be confused with rice vermicelli.

Characteristics
The exact characteristics of glass noodles will depend on their ingredients. The starch used can be derived from mung bean, potato, sweet potato, tapioca, canna, arrowroot, and/or pea. They are typically transparent to translucent when cooked, with a chewy, gelatinous texture and not much flavor. They typically get all their flavor from other ingredients in the final dish.

Types

 * Dangmyeon (당면): Korean variety made from sweet potato starch
 * Fensi (粉絲): Chinese variety
 * Harusame (春雨): Japanese variety made from potato starch
 * Falooda: Indian variety made from arrowroot
 * Kyazan: Burmese variety made from mung bean starch
 * Wun sen (วุ้นเส้น): Thai variety
 * Bún tào: Vietnamese variety made from mung bean starch
 * Miến dong: Vietnamese variety made from canna

Use
Dried cellophane noodles are either soaked in warm water or briefly boiled before adding to the final dish. They cook very quickly, and care must be taken to avoid overcooking, which will make them too soft. After cooking, they can be used in a variety of soups, salads, stir-fries, dumplings, and other dishes. Conveniently, most glass noodles don't become sticky as they cool, preserving their texture.

East Asia
Chinese cellophane noodles are often used in soups or to stuff dumplings and flatbreads. In Korean cuisine, dangmyeon glass noodles are used to make the stir-fried noodle dish called japchae. Japanese harusame are often used in salads.

Southeast Asia
Thai wun sen are often used in the salad called yam wun sen or in the stir-fry dish called phat wun sen. In Vietnam, glass noodles are used to make miến gà, miến lươn, miến măng vịt, and miến cua.

South Asia
Indian falooda noodles are often served with kulfi ice cream, where they provide a textural contrast.

title: Cookbook:Glass Noodle


text:
Cookbook:Ho Fun

Ho fun, also called he fen, chow fun, shahe fen, kway teow, and other variants, are wide flat rice noodles originating in southern Chinese cuisine.

Characteristics
Ho fun are flat and wide, and though the exact width varies, it can reach up to 2 inches. They are made by mixing a dough from rice flour, salt, oil, and water, before steaming, rolling out, and cutting into ribbons. The noodles have a slippery and chewy texture, and they absorb the flavors they are cooked with. Sitting for too long in hot liquid will cause them to soften and disintegrate.

Procurement and storage
Ho fun noodles are often sold fresh, wrapped in plastic. They should be kept away from air, as this will cause them to dry out and become brittle.

Use
The noodles are typically very briefly boiled or steamed before use. They are then often used in stir-fried noodle dishes like chow fun and in some soups.

title: Cookbook:Ho Fun


text:
Windows XP/Printable version

 =Customizing=
 * 1) Changing The Wallpaper
 * 2) Add a Screensaver
 * 3) Changing The Logon Screen
 * 4) Changing the Look
 * 5) Changing Fonts to Display Other Languages

Changing The Wallpaper

Add a Screensaver

Changing The Logon Screen

Changing the Look

Changing Fonts to Display Other Languages

=Securing=
 * 1) Security Fundamentals
 * 2) Backups
 * 3) Practical Steps
 * 4) Security Software
 * 5) End of Support

Security Fundamentals

Backups

Practical Steps

Security Software

End of Support

=Troubleshooting=
 * 1) Installation Problems
 * 2) Removing Windows Passwords
 * 3) Drive Failure

Installation Problems

Removing Windows Passwords

Drive Failure

=Miscellaneous=
 * 1) Optimizing
 * 2) Advanced Optimizing
 * 3) Windows-key Shortcuts
 * 4) Authors & Contributors

Advanced Optimizing

Windows-key Shortcuts

title: Windows XP/Printable version


text:
Windows XP/Main page

Windows XP is a free content online book published on English Wikibooks.

title: Windows XP/Main page


text:
Minesweeper/Authors & Contributors

This list is updated automatically by AuthorsAndContributorsBot. Please do not update it manually.

title: Minesweeper/Authors & Contributors


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Windows Vista/Authors & Contributors

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title: Windows Vista/Authors & Contributors


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Windows XP/Authors & Contributors

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title: Windows XP/Authors & Contributors


text:
User:Daniel Marcel 1/sandbox

Text: Psalms 89:20-24; 103: 1-22; Psalms 34:1-3 Key Verse: Psalm 89:23, “I will beat down his foes before his face, And plague those who hate him.”

David had a thanksgiving lifestyle and was grateful to God for everything He did for him. The Bible told us in Psalms 119:164, that David praised God seven times a day for His righteous judgments. Because of David thanksgiving lifestyle, God said to him, “I will beat down his foes before his face, And plague those who hate him.”

Whenever thanksgiving rises up to God, He is stirred into action to perform a miracle. Be a thanksgiver because thanksgiving releases enormous power of God to do wonders in your life.

Gratitude is a spiritual force that empowers you to scale to higher heights. When you are a grateful, thankful Christian, powerful supernatural forces from heaven are unleashed that cause things to work for you the way they should.

Every time you give genuine thanksgiving fresh oil for fresh impact comes on you. You never run dry with constant thanksgiving (Psalms 89:20-24). When you thank God, you glorifieth His Name, Psalm 50:23.

Thanksgiving has the power to bring encouragement to the testifier and helps to build more confidence in God (Lamentations 3:22-23). David was encouraged, when he was testifying to Saul about how he fought the lion and the bear. He said Goliath would not be a problem.

Thanksgiving brings edification to the hearers. It builds up the faith of others. Romans 10:7 says, faith cometh by hearing, and hearing by the word of God. God is not a respecter of persons. What God did for someone, He can do for others.

Thanksgiving qualifies you for another act of favour from God. Testimony commits God to do more (Proverbs 3:9-10). It propels the testifier to a great height (Psalms 18:1-3). Strength and courage is released, when you thank God.

Thanksgiving brings incredible multiplication. It is one thing to have addition; it is a greater thing to have multiplication (John 6:5-13). The five loaves of bread and two fishes multiplied in the hands of Jesus after He gave thanks to God. Five thousand people were fed and there were about 12, 000 baskets left over (John 6:11&13). Nothing is little in the hands of a thanksgiver, because God will cause an increase.

Thanksgiving turns healing to wholeness. In Luke 17:11-19, 10 lepers cried out to Jesus asking for mercy and He healed them, but only one out of them returned to thank Him. Jesus said to him in v.19, Arise, go thy way: thy faith hath made thee whole. Wholeness is complete health. As you praise and thank God, may you experience His wholeness in Jesus name.

Thanksgiving brings incredible restoration. In John 11:41, Jesus gave thanks and Lazarus rose from the dead. As you give thanks, every opportunity that was dead in your life will be restored in Jesus name.

Thanksgiving brings total deliverance from all your troubles. Psalms 50:14-15, “Offer unto God thanksgiving; and pay thy vows unto the most High. And call upon me in the day of trouble: I will deliver thee, and thou shalt glorify me.”

Thanksgiving provokes the blessings of God upon your life. In 2 Chronicles 1:6-15, Solomon offered unto God a thousand burnt offering and went to bed. He got divine visitation; he got a blank cheque from God; he got divine overflow – more than he asked for and he got divine overwhelming prosperity – silver became like stones. Look at verse 11 God told Solomon, you did not ask for riches, wealth, honour and long life. God added all these blessings as extra to Solomon.

Thanksgiving brings down the glory of God. In 2 Chronicles 5:13-14, when high praises and thanksgiving was rendered to God, His glory filled His house and the priests could not stand. Sickness, disease, sorrow and demons cannot stand, as you give God thanks in Jesus Name. Thanksgiving precedes a new era, a new beginning. If you want a new era of miracles, signs and wonders, then begin with thanksgiving (Luke 22:19-20).

Today’s Nugget: Thanksgiving precedes a new era. Prayer: Father, I pray as I give you thanks continually, may wonders never cease to happen in my life in Jesus Name, Amen.

title: User:Daniel Marcel 1/sandbox


text:
Fractals/Mathematics/doubling

=Definition=

Angle doubling map

 * $$T(r) = (2 r) \bmod 1$$

Input: proper fraction $$r $$ in forms
 * decimal ratio ( if r is not irrational )
 * decimal sequence of digits and radix
 * binary sequence of digits and radix

Output: proper fraction

=Doubling map on binary fraction= Effect of doubling map d on binary representation of fraction x is to simply shift the bits of x to the left, discarding the bit that shifted into the ones place = left shift.

$$ x = 0.b_1 b_2 b_3\dots. $$

$$ d(x) = 0.b_2 b_3\dots. $$

Example
 * $$2*\frac{11}{31} = 2 * 0.01011 = 0.10110 = \frac{22}{31} $$

=Orbits= Iteration of the map gives orbit ( sequence of angles):
 * periodic ( input is a rational number with odd denominator $$d = 2^p - 1$$)
 * preperiodic ( input is rational number with even denominator )
 * aperiodic ( when input is irrational number )

All above types are infinite. Finite binary expansion has equal infinite preperiodic representation.

periodic
Periodic orbits of angles under doubling map

Note that here chord joining 2 points z1 and z2 on unit circle means that $$z_2 = z_1^2$$. It does not mean that these points are landing points of the same ray.

Some orbits do not cross :

Periodic orbits for angles $$ r = \frac{n}{d} $$ with odd denominator d

$$r = \frac{n}{d} = \frac{n}{2^p - 1}$$ Where:
 * n is numerator of the fraction = integer from 0 to (d-1)
 * d is denominator of the fraction = positive integer
 * p is a period = positive integer

Period 1 ( 1 orbit) for angles = $$\frac{n}{2^1 - 1} = \frac{n}{1} $$

{0/1 = 1/1 }

Period 2 ( 1 orbit) for angles = $$\frac{n}{2^2 - 1} = \frac{n}{3} $$

{1/3, 2/3}

Period 3 ( 2 orbits) for angles = $$\frac{n}{2^3 - 1} = \frac{n}{7} $$

{1/7, 2/7, 4/7 } {3/7, 6/7, 5/7 }

Period 4 ( 3 orbits) for angles = $$\frac{n}{2^4 - 1} = \frac{n}{15} $$

{1/15, 2/15,  4/15,  8/15 } {3/15,  6/15, 12/15,  9/15 } {7/15, 14/15, 13/15, 11/15 } Period 5 ( 6 orbits) for angles = $$\frac{n}{2^5 - 1} = \frac{n}{31} $$

{ 1/31, 2/31,  4/31,  8/31, 16/31} { 3/31,  6/31, 12/31, 24/31, 17/31} { 5/31, 10/31, 20/31,  9/31, 18/31} { 7/31, 14/31, 28/31, 25/31, 19/31} {11/31, 22/31, 13/31, 26/31, 21/31} {15/31, 30/31, 29/31, 27/31, 23/31}

Period 6 ( 9 orbits ) for angles = $$\frac{n}{2^6 - 1} = \frac{n}{63} $$, only numerators

{ 1, 2, 4, 8,16,32} { 3, 6,12,24,48,33} { 5,10,20,40,17,34} { 7,14,28,56,49,35} [11,22,44,25,50,37} [13,26,52,41,19,38} [15,30,60,57,51,39} [23,46,29,58,53,43] [31,62,61,59,55,47]

Period = 7 for angles = $$\frac{n}{2^7 - 1} = \frac{n}{127} $$

Period = 8 for angles = $$\frac{n}{2^8 - 1} = \frac{n}{255} $$

Period = 9 for angles = $$\frac{n}{2^9 - 1} = \frac{n}{511} $$

See also
 * external ray for root points ( bond point) on the parameter plane:
 * wake
 * subwake
 * island = midget = mini Mandelbrot set
 * dynamic plane
 * external rays that land on the parabolic fixed point . ( first angle is angle of the wake)

preperiodic
Here denominator d of fraction r

 * $$r = \frac{n}{d}$$

is even:

 * $$d = 2^tq$$

and q is odd.

Here
 * t is preperiod

Example orbits:

Preperiod 1 and period 1 for angles $$\frac{n}{2}$$

{1/2, (0/2)}

See
 * Misiurewicz points on the parameter plane
 * Dendrite Julia sets on the dynamic plane

aperiodic

Compare
 * Siegel disc
 * Herman rings ( rational maps)

= Implementations =
 * integer:
 * 2 integers ( numerator and denominator)
 * rational number
 * mpq type from GMP library
 * floating point
 * double

Forward

 * Using 32bit signed int limits maximum preperiod to about 30
 * Using double for fractions limits maximum number of accurate bits to about 53

C using double numbers

 * using double gives precision of 53 bits of binary number expansion (the number of bits of accuracy of double precision floating point)

C using rational type mpq from GMP library ( arbitrary precision)
C function (using GMP library) :

Compile: gcc r.c -lgmp

run ./a.out

result:

a rational number 1 / 6 is in a canonical form ( decimal fraction) : 1/6 numerator of rational number = 1 denominator of rational number = 6 binary rational ( string ) : 1/110 decimal floating point number : 0.166666666666666666667 mantissa of binary floating ( string ) : 101010101010101010101010101010101010101010101010101010101010101011 exponent : -2 binary floatin in exponential form =0.101010101010101010101010101010101010101010101010101010101010101011*2^-2

Maxima CAS

 * Maxima CAS function using numerator and denominator as an input

doubling_map(n,d):=mod(2*n,d)/d $

or using rational number as an input

DoublingMap(r):= block([d,n],        n:ratnumer(r),         d:ratdenom(r),         mod(2*n,d)/d)$

Haskell
Haskell function

Inverse function of doubling map
Every angle α ∈ R/Z measured in turns has:
 * one image = 2α mod 1 under doubling map
 * "two preimages under the doubling map: α/2 and (α + 1)/2.". Inverse of doubling map is multivalued function.

In Maxima CAS:

InvDoublingMap(r):= [r/2, (r+1)/2];

Note that difference between these 2 preimages

 * $$\frac{\alpha}{2} - \frac{\alpha +1}{2} = \frac{1}{2}$$

is half a turn = 180 degrees = Pi radians.

=Q&A=

analysis

 * find expansion type
 * find preperiod and period
 * convert decimal fraction to binary expansion
 * format the expansion

How to find expansion type
Binary expansion of decimal fraction

How to find preperiod and period ?

 * Period and the doubling map

How to find the period of angle under doubling map
 * visual
 * numerical
 * read period from denominator of decimal fraction ( reduced rational fraction m/n )
 * find period/preperiod in the binary expansion ( binary sequence)
 * string matching algorithms, for instance, naive or brute-force search, Knuth-Morris-Pratt algorithm
 * discrete Fourier transform
 * read it from the itinerary of angle under doubling map

Period of binary expansion of reduced rational fraction m/n is equal to the multiplicative order of 2 modulo n:

$$ Period_2(m/n) = {ord}_n(2)$$

Maxima CAS version
DoublingMap(r):= block([d,n], n:ratnumer(r), d:ratdenom(r), mod(2*n,d)/d)$

/* Tests : GivePeriod (1/7) 3 GivePeriod (1/14) 0 GivePeriod (1/32767) 15 GivePeriod (65533/65535) 16

Gives 0 if :
 * not periodic ( preperiodic )
 * period >pMax

GivePeriod (r):= block([rNew, rOld, period, pMax, p],     pMax:100,      period:0,      p:1,       rNew:DoublingMap(r),      while ((p<pMax) and notequal(rNew,r)) do        (rOld:rNew, rNew:DoublingMap(rOld), p:p+1 ),     if equal(rNew,r) then period:p,      period );

Haskell version
Haskell version

Conversion from an integer type (Int or Integer) to anything else is done by "fromIntegral". The target type is inferred automatically

conversion

 * Convert binary fraction to decimal ratio
 * convert decimal fraction to binary
 * knowledgedoor calculators

Can all decimal fractions be converted exactly to binary?
Not all. Only those for which denominator is a power of 2 ( finite ) have exact decimal representation. "In every other case, there will be an error in the representation. The error's magnitude depends on the number of digits used to represent it."

precision
What number type precision do I need for computing doubling map?
 * "the doubling map loses one bit of precision with every iterate."
 * storing the angle as an exact rational (e.g. mpq_t using libgmp), allows it to be accurate for more than 53 iterations (the number of bits of accuracy of double precision floating point). Convert to double only when needing to do sin and cos for finding the target point.  Double is plenty accurate for target point. Claude Heiland-Allen

=See also=
 * binary fraction

=References=

title: Fractals/Mathematics/doubling