CesiumMath

Math functions.

Source:

/Source/Core/Math.js

Members

<static, constant> DEGREES_PER_RADIAN :Number

The number of degrees in a radian.

Default Value:

180.0 / Math.PI

See:

czm_degreesPerRadian

<static, constant> EPSILON1 :Number

0.1

<static, constant> EPSILON10 :Number

0.0000000001

<static, constant> EPSILON11 :Number

0.00000000001

<static, constant> EPSILON12 :Number

0.000000000001

<static, constant> EPSILON13 :Number

0.0000000000001

<static, constant> EPSILON14 :Number

0.00000000000001

<static, constant> EPSILON15 :Number

0.000000000000001

<static, constant> EPSILON16 :Number

0.0000000000000001

<static, constant> EPSILON17 :Number

0.00000000000000001

<static, constant> EPSILON18 :Number

0.000000000000000001

<static, constant> EPSILON19 :Number

0.0000000000000000001

<static, constant> EPSILON2 :Number

0.01

<static, constant> EPSILON20 :Number

0.00000000000000000001

<static, constant> EPSILON3 :Number

0.001

<static, constant> EPSILON4 :Number

0.0001

<static, constant> EPSILON5 :Number

0.00001

<static, constant> EPSILON6 :Number

0.000001

<static, constant> EPSILON7 :Number

0.0000001

<static, constant> EPSILON8 :Number

0.00000001

<static, constant> EPSILON9 :Number

0.000000001

<static, constant> GRAVITATIONALPARAMETER :Number

3.986004418e14

<static, constant> LUNAR_RADIUS :Number

The mean radius of the moon, according to the "Report of the IAU/IAG Working Group on Cartographic Coordinates and Rotational Elements of the Planets and satellites: 2000", Celestial Mechanics 82: 83-110, 2002.

<static, constant> ONE_OVER_PI :Number

1/pi

See:

czm_oneOverPi

<static, constant> ONE_OVER_TWO_PI :Number

1/2pi

See:

czm_oneOverTwoPi

<static, constant> PI :Number

See:

czm_pi

<static, constant> PI_OVER_FOUR :Number

pi/4

See:

czm_piOverFour

<static, constant> PI_OVER_SIX :Number

pi/6

See:

czm_piOverSix

<static, constant> PI_OVER_THREE :Number

pi/3

See:

czm_piOverThree

<static, constant> PI_OVER_TWO :Number

pi/2

See:

czm_piOverTwo

<static, constant> RADIANS_PER_ARCSECOND :Number

The number of radians in an arc second.

Default Value:

CesiumMath.RADIANS_PER_DEGREE / 3600.0

See:

czm_radiansPerArcSecond

<static, constant> RADIANS_PER_DEGREE :Number

The number of radians in a degree.

Default Value:

Math.PI / 180.0

See:

czm_radiansPerDegree

<static, constant> SIXTY_FOUR_KILOBYTES :Number

64 * 1024

<static, constant> SOLAR_RADIUS :Number

Radius of the sun in meters: 6.955e8

<static, constant> THREE_PI_OVER_TWO :Number

3pi/2

See:

czm_threePiOver2

<static, constant> TWO_PI :Number

2pi

See:

czm_twoPi

Methods

<static> clamp

Constraint a value to lie between two values.

Parameters:

Name	Type	Description
`value`	Number	The value to constrain.
`min`	Number	The minimum value.
`max`	Number	The maximum value.

Returns:

The value clamped so that min <= value <= max.

<static> convertLongitudeRange

Converts a longitude value, in radians, to the range [-Math.PI, Math.PI).

Parameters:

Name	Type	Description
`angle`	Number	The longitude value, in radians, to convert to the range [`-Math.PI`, `Math.PI`).

Returns:

Number The equivalent longitude value in the range [-Math.PI, Math.PI).

Example

// Convert 270 degrees to -90 degrees longitude
var longitude = CesiumMath.convertLongitudeRange(CesiumMath.toRadians(270.0));

<static> cosh

Returns the hyperbolic cosine of a {@code Number}. The hyperbolic cosine of value is defined to be (e^x + e^-x)/2.0 where e is Euler's number, approximately 2.71828183.

Special cases:

If the argument is NaN, then the result is NaN.
If the argument is infinite, then the result is positive infinity.
If the argument is zero, then the result is {@code 1.0}.

Parameters:

Name	Type	Description
`value`		The number whose hyperbolic cosine is to be returned.

Returns:

The hyperbolic cosine of {@code value}.

<static> equalsEpsilon

DOC_TBA

<static> factorial

Computes the factorial of the provided number.

Parameters:

Name	Type	Description
`n`	Number	The number whose factorial is to be computed.

Throws:

DeveloperError : A number greater than or equal to 0 is required.

Returns:

Number The factorial of the provided number or undefined if the number is less than 0.

Example

//Compute 7!, which is equal to 5040
var computedFactorial = CesiumMath.factorial(7);

See:

Factorial on Wikipedia.

<static> incrementWrap

Increments a number with a wrapping to a minimum value if the number exceeds the maximum value.

Parameters:

Name	Type	Argument	Default	Description
`n`	Number	<optional>		The number to be incremented.
`maximumValue`	Number	<optional>		The maximum incremented value before rolling over to the minimum value.
`minimumValue`	Number	<optional>	0.0	The number reset to after the maximum value has been exceeded.

Throws:

DeveloperError : Maximum value must be greater than minimum value.

Returns:

Number The incremented number.

Example

var n = CesiumMath.incrementWrap(5, 10, 0); // returns 6
var n = CesiumMath.incrementWrap(10, 10, 0); // returns 0

<static> isPowerOfTwo

Determines if a positive integer is a power of two.

Parameters:

Name	Type	Description
`n`	Number	The positive integer to test.

Throws:

DeveloperError : A number greater than or equal to 0 is required.

Returns:

Boolean true if the number if a power of two; otherwise, false.

Example

var t = CesiumMath.isPowerOfTwo(16); // true
var f = CesiumMath.isPowerOfTwo(20); // false

<static> lerp

DOC_TBA

<static> negativePiToPi

Produces an angle in the range 0 <= angle <= 2Pi which is equivalent to the provided angle.

Parameters:

Name	Type	Description
`angle`	Number	in radians

Returns:

Number The angle in the range ()-CesiumMath.PI, CesiumMath.PI).

<static> nextPowerOfTwo

Computes the next power-of-two integer greater than or equal to the provided positive integer.

Parameters:

Name	Type	Description
`n`	Number	The positive integer to test.

Throws:

DeveloperError : A number greater than or equal to 0 is required.

Returns:

Number The next power-of-two integer.

Example

var n = CesiumMath.nextPowerOfTwo(29); // 32
var m = CesiumMath.nextPowerOfTwo(32); // 32

<static> nextRandomNumber

Generates a random number in the range of [0.0, 1.0) using a Mersenne twister.

Returns:

A random number in the range of [0.0, 1.0).

See:

CesiumMath#setRandomNumberSeed
http://en.wikipedia.org/wiki/Mersenne_twister

<static> setRandomNumberSeed

Sets the seed used by the random number generator in CesiumMath#nextRandomNumber.

Parameters:

Name	Type	Description
`seed`	Number	An integer used as the seed.

Throws:

DeveloperError : seed is required.

<static> sign

Returns the sign of the value; 1 if the value is positive, -1 if the value is negative, or 0 if the value is 0.

Parameters:

Name	Type	Description
`value`	Number	The value to return the sign of.

Returns:

Number The sign of value.

<static> sinh

Returns the hyperbolic sine of a {@code Number}. The hyperbolic sine of value is defined to be (e^x - e^-x)/2.0 where e is Euler's number, approximately 2.71828183.

Special cases:

If the argument is NaN, then the result is NaN.
If the argument is infinite, then the result is an infinity with the same sign as the argument.
If the argument is zero, then the result is a zero with the same sign as the argument.

Parameters:

Name	Type	Description
`value`		The number whose hyperbolic sine is to be returned.

Returns:

The hyperbolic sine of {@code value}.

<static> toDegrees

Converts radians to degrees.

Parameters:

Name	Type	Description
`radians`	Number	The angle to convert in radians.

Returns:

Number The corresponding angle in degrees.

<static> toRadians

Converts degrees to radians.

Parameters:

Name	Type	Description
`degrees`	Number	The angle to convert in degrees.

Returns:

Number The corresponding angle in radians.

<static> zeroToTwoPi

Produces an angle in the range -Pi <= angle <= Pi which is equivalent to the provided angle.

Parameters:

Name	Type	Description
`angle`	Number	in radians

Returns:

Number The angle in the range (0 , CesiumMath.TWO_PI).