CesiumMath

Math functions.
Source: Core/Math.js, line 20

Members

staticconstantCesiumMath.DEGREES_PER_RADIAN :Number

The number of degrees in a radian.
Default Value: 180.0 / Math.PI
Source: Core/Math.js, line 400

staticconstantCesiumMath.EPSILON1 :Number

0.1
Source: Core/Math.js, line 27

staticconstantCesiumMath.EPSILON2 :Number

0.01
Source: Core/Math.js, line 34

staticconstantCesiumMath.EPSILON3 :Number

0.001
Source: Core/Math.js, line 41

staticconstantCesiumMath.EPSILON4 :Number

0.0001
Source: Core/Math.js, line 48

staticconstantCesiumMath.EPSILON5 :Number

0.00001
Source: Core/Math.js, line 55

staticconstantCesiumMath.EPSILON6 :Number

0.000001
Source: Core/Math.js, line 62

staticconstantCesiumMath.EPSILON7 :Number

0.0000001
Source: Core/Math.js, line 69

staticconstantCesiumMath.EPSILON8 :Number

0.00000001
Source: Core/Math.js, line 76

staticconstantCesiumMath.EPSILON9 :Number

0.000000001
Source: Core/Math.js, line 83

staticconstantCesiumMath.EPSILON10 :Number

0.0000000001
Source: Core/Math.js, line 90

staticconstantCesiumMath.EPSILON11 :Number

0.00000000001
Source: Core/Math.js, line 97

staticconstantCesiumMath.EPSILON12 :Number

0.000000000001
Source: Core/Math.js, line 104

staticconstantCesiumMath.EPSILON13 :Number

0.0000000000001
Source: Core/Math.js, line 111

staticconstantCesiumMath.EPSILON14 :Number

0.00000000000001
Source: Core/Math.js, line 118

staticconstantCesiumMath.EPSILON15 :Number

0.000000000000001
Source: Core/Math.js, line 125

staticconstantCesiumMath.EPSILON16 :Number

0.0000000000000001
Source: Core/Math.js, line 132

staticconstantCesiumMath.EPSILON17 :Number

0.00000000000000001
Source: Core/Math.js, line 139

staticconstantCesiumMath.EPSILON18 :Number

0.000000000000000001
Source: Core/Math.js, line 146

staticconstantCesiumMath.EPSILON19 :Number

0.0000000000000000001
Source: Core/Math.js, line 153

staticconstantCesiumMath.EPSILON20 :Number

0.00000000000000000001
Source: Core/Math.js, line 160

staticconstantCesiumMath.GRAVITATIONALPARAMETER :Number

3.986004418e14
Source: Core/Math.js, line 167

staticconstantCesiumMath.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.
Source: Core/Math.js, line 183

staticconstantCesiumMath.ONE_OVER_PI :Number

1/pi
Source: Core/Math.js, line 326

staticconstantCesiumMath.ONE_OVER_TWO_PI :Number

1/2pi
Source: Core/Math.js, line 382

staticconstantCesiumMath.PI :Number

pi
Source: Core/Math.js, line 318

staticconstantCesiumMath.PI_OVER_FOUR :Number

pi/4
Source: Core/Math.js, line 350

staticconstantCesiumMath.PI_OVER_SIX :Number

pi/6
Source: Core/Math.js, line 358

staticconstantCesiumMath.PI_OVER_THREE :Number

pi/3
Source: Core/Math.js, line 342

staticconstantCesiumMath.PI_OVER_TWO :Number

pi/2
Source: Core/Math.js, line 334

staticconstantCesiumMath.RADIANS_PER_ARCSECOND :Number

The number of radians in an arc second.
Default Value: CesiumMath.RADIANS_PER_DEGREE / 3600.0
Source: Core/Math.js, line 409

staticconstantCesiumMath.RADIANS_PER_DEGREE :Number

The number of radians in a degree.
Default Value: Math.PI / 180.0
Source: Core/Math.js, line 391

staticconstantCesiumMath.SIXTY_FOUR_KILOBYTES :Number

64 * 1024
Source: Core/Math.js, line 190

staticconstantCesiumMath.SOLAR_RADIUS :Number

Radius of the sun in meters: 6.955e8
Source: Core/Math.js, line 174

staticconstantCesiumMath.THREE_PI_OVER_TWO :Number

3pi/2
Source: Core/Math.js, line 366

staticconstantCesiumMath.TWO_PI :Number

2pi
Source: Core/Math.js, line 374

Methods

staticCesiumMath.acosClamped(value) → Number

Computes Math.acos(value), but first clamps value to the range [-1.0, 1.0] so that the function will never return NaN.
Name Type Description
value Number The value for which to compute acos.
Returns:
The acos of the value if the value is in the range [-1.0, 1.0], or the acos of -1.0 or 1.0, whichever is closer, if the value is outside the range.
Source: Core/Math.js, line 738

staticCesiumMath.asinClamped(value) → Number

Computes Math.asin(value), but first clamps value to the range [-1.0, 1.0] so that the function will never return NaN.
Name Type Description
value Number The value for which to compute asin.
Returns:
The asin of the value if the value is in the range [-1.0, 1.0], or the asin of -1.0 or 1.0, whichever is closer, if the value is outside the range.
Source: Core/Math.js, line 755

staticCesiumMath.chordLength(angle, radius) → Number

Finds the chord length between two points given the circle's radius and the angle between the points.
Name Type Description
angle Number The angle between the two points.
radius Number The radius of the circle.
Returns:
The chord length.
Source: Core/Math.js, line 771

staticCesiumMath.clamp(value, min, max) → Number

Constraint a value to lie between two values.
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.
Source: Core/Math.js, line 684

staticCesiumMath.convertLongitudeRange(angle) → Number

Converts a longitude value, in radians, to the range [-Math.PI, Math.PI).
Name Type Description
angle Number The longitude value, in radians, to convert to the range [-Math.PI, Math.PI).
Returns:
The equivalent longitude value in the range [-Math.PI, Math.PI).
Example:
// Convert 270 degrees to -90 degrees longitude
var longitude = Cesium.Math.convertLongitudeRange(Cesium.Math.toRadians(270.0));
Source: Core/Math.js, line 449

staticCesiumMath.cosh(value)

Returns the hyperbolic cosine of a number. The hyperbolic cosine of value is defined to be (ex + 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 1.0.

Name Type Description
value Number The number whose hyperbolic cosine is to be returned.
Returns:
The hyperbolic cosine of value.
Source: Core/Math.js, line 290

staticCesiumMath.equalsEpsilon(left, right, relativeEpsilon, absoluteEpsilon) → Boolean

Determines if two values are equal using an absolute or relative tolerance test. This is useful to avoid problems due to roundoff error when comparing floating-point values directly. The values are first compared using an absolute tolerance test. If that fails, a relative tolerance test is performed. Use this test if you are unsure of the magnitudes of left and right.
Name Type Default Description
left Number The first value to compare.
right Number The other value to compare.
relativeEpsilon Number The maximum inclusive delta between left and right for the relative tolerance test.
absoluteEpsilon Number relativeEpsilon optional The maximum inclusive delta between left and right for the absolute tolerance test.
Returns:
true if the values are equal within the epsilon; otherwise, false.
Example:
var a = Cesium.Math.equalsEpsilon(0.0, 0.01, Cesium.Math.EPSILON2); // true
var b = Cesium.Math.equalsEpsilon(0.0, 0.1, Cesium.Math.EPSILON2);  // false
var c = Cesium.Math.equalsEpsilon(3699175.1634344, 3699175.2, Cesium.Math.EPSILON7); // true
var d = Cesium.Math.equalsEpsilon(3699175.1634344, 3699175.2, Cesium.Math.EPSILON9); // false
Source: Core/Math.js, line 540

staticCesiumMath.factorial(n) → Number

Computes the factorial of the provided number.
Name Type Description
n Number The number whose factorial is to be computed.
Returns:
The factorial of the provided number or undefined if the number is less than 0.
Throws:
Example:
//Compute 7!, which is equal to 5040
var computedFactorial = Cesium.Math.factorial(7);
See:
Source: Core/Math.js, line 573

staticCesiumMath.fromSNorm(value) → Number

Converts a SNORM value in the range [0, 255] to a scalar in the range [-1.0, 1.0].
Name Type Description
value Number SNORM value in the range [0, 255]
Returns:
Scalar in the range [-1.0, 1.0].
See:
Source: Core/Math.js, line 239

staticCesiumMath.incrementWrap(n, maximumValue, minimumValue) → Number

Increments a number with a wrapping to a minimum value if the number exceeds the maximum value.
Name Type 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 0.0 optional The number reset to after the maximum value has been exceeded.
Returns:
The incremented number.
Throws:
Example:
var n = Cesium.Math.incrementWrap(5, 10, 0); // returns 6
var n = Cesium.Math.incrementWrap(10, 10, 0); // returns 0
Source: Core/Math.js, line 604

staticCesiumMath.isPowerOfTwo(n) → Boolean

Determines if a positive integer is a power of two.
Name Type Description
n Number The positive integer to test.
Returns:
true if the number if a power of two; otherwise, false.
Throws:
Example:
var t = Cesium.Math.isPowerOfTwo(16); // true
var f = Cesium.Math.isPowerOfTwo(20); // false
Source: Core/Math.js, line 635

staticCesiumMath.lerp(p, q, time) → Number

Computes the linear interpolation of two values.
Name Type Description
p Number The start value to interpolate.
q Number The end value to interpolate.
time Number The time of interpolation generally in the range [0.0, 1.0].
Returns:
The linearly interpolated value.
Example:
var n = Cesium.Math.lerp(0.0, 2.0, 0.5); // returns 1.0
Source: Core/Math.js, line 308

staticCesiumMath.mod(m, n) → Number

The modulo operation that also works for negative dividends.
Name Type Description
m Number The dividend.
n Number The divisor.
Returns:
The remainder.
Source: Core/Math.js, line 510

staticCesiumMath.negativePiToPi(angle) → Number

Produces an angle in the range -Pi <= angle <= Pi which is equivalent to the provided angle.
Name Type Description
angle Number in radians
Returns:
The angle in the range [-CesiumMath.PI, CesiumMath.PI].
Source: Core/Math.js, line 475

staticCesiumMath.nextPowerOfTwo(n) → Number

Computes the next power-of-two integer greater than or equal to the provided positive integer.
Name Type Description
n Number The positive integer to test.
Returns:
The next power-of-two integer.
Throws:
Example:
var n = Cesium.Math.nextPowerOfTwo(29); // 32
var m = Cesium.Math.nextPowerOfTwo(32); // 32
Source: Core/Math.js, line 657

staticCesiumMath.nextRandomNumber() → Number

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:
Source: Core/Math.js, line 726

staticCesiumMath.setRandomNumberSeed(seed)

Sets the seed used by the random number generator in CesiumMath#nextRandomNumber.
Name Type Description
seed Number An integer used as the seed.
Source: Core/Math.js, line 707

staticCesiumMath.sign(value) → Number

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.
Name Type Description
value Number The value to return the sign of.
Returns:
The sign of value.
Source: Core/Math.js, line 199

staticCesiumMath.signNotZero(value) → Number

Returns 1.0 if the given value is positive or zero, and -1.0 if it is negative. This is similar to CesiumMath#sign except that returns 1.0 instead of 0.0 when the input value is 0.0.
Name Type Description
value Number The value to return the sign of.
Returns:
The sign of value.
Source: Core/Math.js, line 217

staticCesiumMath.sinh(value)

Returns the hyperbolic sine of a number. The hyperbolic sine of value is defined to be (ex - 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.

Name Type Description
value Number The number whose hyperbolic sine is to be returned.
Returns:
The hyperbolic sine of value.
Source: Core/Math.js, line 264

staticCesiumMath.toDegrees(radians) → Number

Converts radians to degrees.
Name Type Description
radians Number The angle to convert in radians.
Returns:
The corresponding angle in degrees.
Source: Core/Math.js, line 430

staticCesiumMath.toRadians(degrees) → Number

Converts degrees to radians.
Name Type Description
degrees Number The angle to convert in degrees.
Returns:
The corresponding angle in radians.
Source: Core/Math.js, line 416

staticCesiumMath.toSNorm(value) → Number

Converts a scalar value in the range [-1.0, 1.0] to a 8-bit 2's complement number.
Name Type Description
value Number The scalar value in the range [-1.0, 1.0]
Returns:
The 8-bit 2's complement number, where 0 maps to -1.0 and 255 maps to 1.0.
See:
Source: Core/Math.js, line 228

staticCesiumMath.zeroToTwoPi(angle) → Number

Produces an angle in the range 0 <= angle <= 2Pi which is equivalent to the provided angle.
Name Type Description
angle Number in radians
Returns:
The angle in the range [0, CesiumMath.TWO_PI].
Source: Core/Math.js, line 490