в 09:19, 26 мая 2010

2010-05-26T09:19:13Z

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2010-05-26T08:15:00Z

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==All trig functions operate on radians, an angular unit in which radians measure a full revolution.==



<source lang="java">

package{
import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
var valInRadians;
var valInDegrees;
valInRadians = valInDegrees / 180 * Math.PI;
valInDegrees = valInRadians / Math.PI * 180;
}
}
}
</source>

==atan2(), takes two parameters (an X- and a Y-coordinate), and returns the angle formed by the right triangle measured in radians: Math.atan2(x, y)==



<source lang="java">

package{
import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
trace(Math.atan2(2,3));
}
}
}
</source>

==Finding Absolute Values==



<source lang="java">

package{
import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
var nValue:int = 10;

if(nValue < 10 && nValue > -10) {
// Code goes here.
}
//can be rewritten in the following way using the abs() method:
if(Math.abs(nValue) < 10) {
// Code goes here.
}
}
}
}
</source>

==Finding the Greater or Lesser of Two Numbers==



<source lang="java">

package{
import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
trace(Math.min(25, 2)); // Displays: 2
trace(Math.max(25, 2)); // Displays: 25

}
}
}
</source>

==Generate a random number within a range that does not start with 0==



<source lang="java">

package{
import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
var nRandomFloat:Number = (Math.random() * 10) + 20;
}
}
}
</source>

==Generate random number in a range==



<source lang="java">

package{
import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
trace(randomInRange(2,5));
}
function randomInRange(min:Number, max:Number):Number {
var scale:Number = max - min;
return Math.random() * scale + min;
}
}
}
</source>

==Generating Random Numbers: The random() returns a floating-point value between 0 and 0.999999, inclusive.==



<source lang="java">

package{
import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
var randomFloat:Number = Math.random() * 2;

var nRandomFloat:Number = Math.random() * 45;

trace(nRandomFloat);
}
}
}
</source>

==If you are working with one six-sided die, you want to generate a random number between 1 and 6 each time==



<source lang="java">

package{
import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
var nValue:Number = Math.floor(Math.random() * 6) + 1;
trace(nValue);
}
}
}
</source>

==Math Class Arithmetic==



<source lang="java">

Method Call Returns
Math.pow(a, b) a raised to the b power (ab)
Math.exp(a) e raised to the a power (ea)
Math.floor(a) a rounded down
Math.ceil(a) a rounded up
Math.round(a) a rounded to the nearest digit
Math.max(a, b, c...) Maximum of the set a, b, c â��
Math.min(a, b, c...) Minimum of the set a, b, c â��
Math.sqrt(a) Square root of a
Math.abs(a) Absolute value of a
Math.log(a) Logarithm (base 10) of a
Math.ln(a) Natural logarithm (base e) of a
</source>

==Math class includes the constant Math.PI for the number, ratio of a circle"s circumference to its diameter.==



<source lang="java">

package{
import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
trace(Math.PI);
}
}
}
</source>

==Math Class Trigonometry==



<source lang="java">

Method Call Returns
Math.sin(a) Sine of an angle measuring a radians
Math.cos(a) Cosine of an angle measuring a radians
Math.tan(a) Tangent of an angle measuring a radians
Math.asin(a) Angle in radians whose sine is a (arcsine of a)
Math.acos(a) Angle in radians whose cosine is a (arccosine of a)
Math.atan(a) Angle in radians whose tangent is a (arctangent of a)
Math.atan2(y, x) Angle which, drawn from the origin, intersects the point (x, y) (arctangent of y/x)
</source>

==Math Constants==



<source lang="java">

Property Value Description
E ~2.718 Base of natural logarithm
LN10 ~2.302 Natural logarithm of 10
LN2 ~0.693 Natural logarithm of 2
LOG10E ~0.434 Base-10 logarithm of E
LOG2E ~1.442 Base-2 logarithm of E
PI ~3.142 Pi
SQRT1_2 ~0.707 Square root of 1/2
SQRT2 ~1.414 Square root of 2
</source>

==package{==



<source lang="java">

import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
var nPathRadius:Number = 100;
var nDegrees:Number = 0;

var nRadians:Number = nDegrees * (Math.PI / 180);

var nX:Number = nPathRadius * Math.sin(nRadians);
var nY:Number = nPathRadius * Math.cos(nRadians);

trace(nX);
trace(nY);

}
}
}
</source>

==Random integer values==



<source lang="java">

package{
import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
var nRandomInteger:Number = Math.floor(Math.random()*10);
trace(nRandomInteger);

nRandomInteger = Math.floor(Math.random()*10) + 1;
trace(nRandomInteger);
}
}
}
</source>

==Rounding and Truncating Numbers: round(), ceiling(), and floor()==



<source lang="java">

package{
import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
trace(Math.round(5.75)); // Displays: 6
trace(Math.round(93.3)); // Displays: 93
}
}
}
</source>

==The calculation for finding compound interest: newValue = originalValue * (1 + rate/cp)^(cp*t)==



<source lang="java">

cp is the number of compounding periods per year (12 if it is compounded every month)
t is the number of years.
package{
import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
var nOrig: int = 10;
var nRate:int = 2;
var nCp: int = 3;
var nT: int = 3;

var nNew = nOrig * Math.pow((1 + nRate/nCp), (nCp*nT));
trace(nNew);
}
}
}
</source>

==The ceil() method returns the next-highest integer value of the number passed it as an argument.==



<source lang="java">

package{
import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
trace(Math.ceil(5.75)); // Displays: 6
trace(Math.ceil(93.3)); // Displays: 94
trace(Math.ceil(93)); // Displays: 93
}
}
}
</source>

==The exp() method requires one parameter: a number. It then raises e (Math.E) to the power of that number.==



<source lang="java">

package{
import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
if(Math.exp(5) == Math.pow(Math.E, 5)){
trace("=");
}
}
}
}
</source>

==The floor()returns the next-lowest integer.==



<source lang="java">

package{
import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
trace(Math.floor(5.75)); // Displays: 5
trace(Math.floor(93.3)); // Displays: 93
trace(Math.floor(93)); // Displays: 93
}
}
}
</source>

==To round a number to the nearest decimal place:==



<source lang="java">

package{
import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
trace (Math.round(90.337 / .01) * .01); // Displays: 9.34
}
}
}
</source>

==Use Math.ceil( ) to round a number up.==



<source lang="java">

package{
import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
trace(Math.ceil(401.01)); // Displays: 402
}
}
}
</source>

==Use Math.floor( ) to round a number down==



<source lang="java">

package{
import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
trace(Math.floor(204.99)); // Displays: 204
}
}
}
</source>

==Use Math.round( ) to round a number to the nearest integer==



<source lang="java">

package{
import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
trace(Math.round(204.499)); // Displays: 204
trace(Math.round(401.5)); // Displays: 402
}
}
}
</source>

==Use round(), ceiling(), and floor() to round or truncate to decimal place values.==



<source lang="java">

package{
import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
var nValue:Number = 6.39639;
nValue *= 100;
nValue = Math.floor(nValue);
nValue /= 100;
trace(nValue); // Displays: 6.39
}
}
}
</source>

==Use the identical math to round a number to the nearest multiple of an integer.==



<source lang="java">

package{
import flash.display.Sprite;

public class Main extends Sprite{
public function Main(){
trace (Math.round(92.5 / 5) * 5); // Displays: 95
}
}
}
</source>

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в 09:19, 26 мая 2010

Admin: 1 версия