Math

Math()
Core/Math.js 13

Math functions.

Members

static constant Cesium.Math.DEGREES_PER_RADIAN : Number
Core/Math.js 426

The number of degrees in a radian.

static constant Cesium.Math.EPSILON1 : Number
Core/Math.js 20

0.1

static constant Cesium.Math.EPSILON2 : Number
Core/Math.js 27

0.01

static constant Cesium.Math.EPSILON3 : Number
Core/Math.js 34

0.001

static constant Cesium.Math.EPSILON4 : Number
Core/Math.js 41

0.0001

static constant Cesium.Math.EPSILON5 : Number
Core/Math.js 48

0.00001

static constant Cesium.Math.EPSILON6 : Number
Core/Math.js 55

0.000001

static constant Cesium.Math.EPSILON7 : Number
Core/Math.js 62

0.0000001

static constant Cesium.Math.EPSILON8 : Number
Core/Math.js 69

0.00000001

static constant Cesium.Math.EPSILON9 : Number
Core/Math.js 76

0.000000001

static constant Cesium.Math.EPSILON10 : Number
Core/Math.js 83

0.0000000001

static constant Cesium.Math.EPSILON11 : Number
Core/Math.js 90

0.00000000001

static constant Cesium.Math.EPSILON12 : Number
Core/Math.js 97

0.000000000001

static constant Cesium.Math.EPSILON13 : Number
Core/Math.js 104

0.0000000000001

static constant Cesium.Math.EPSILON14 : Number
Core/Math.js 111

0.00000000000001

static constant Cesium.Math.EPSILON15 : Number
Core/Math.js 118

0.000000000000001

static constant Cesium.Math.EPSILON16 : Number
Core/Math.js 125

0.0000000000000001

static constant Cesium.Math.EPSILON17 : Number
Core/Math.js 132

0.00000000000000001

static constant Cesium.Math.EPSILON18 : Number
Core/Math.js 139

0.000000000000000001

static constant Cesium.Math.EPSILON19 : Number
Core/Math.js 146

0.0000000000000000001

static constant Cesium.Math.EPSILON20 : Number
Core/Math.js 153

0.00000000000000000001

static constant Cesium.Math.EPSILON21 : Number
Core/Math.js 160

0.000000000000000000001

static constant Cesium.Math.FOUR_GIGABYTES : Number
Core/Math.js 198

4 * 1024 * 1024 * 1024

static constant Cesium.Math.GRAVITATIONALPARAMETER : Number
Core/Math.js 168

The gravitational parameter of the Earth in meters cubed per second squared as defined by the WGS84 model: 3.986004418e14

static constant Cesium.Math.LUNAR_RADIUS : Number
Core/Math.js 184

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 Cesium.Math.ONE_OVER_PI : Number
Core/Math.js 354

1/pi

static constant Cesium.Math.ONE_OVER_TWO_PI : Number
Core/Math.js 410

1/2pi

static constant Cesium.Math.PI : Number
Core/Math.js 346

pi

static constant Cesium.Math.PI_OVER_FOUR : Number
Core/Math.js 378

pi/4

static constant Cesium.Math.PI_OVER_SIX : Number
Core/Math.js 386

pi/6

static constant Cesium.Math.PI_OVER_THREE : Number
Core/Math.js 370

pi/3

static constant Cesium.Math.PI_OVER_TWO : Number
Core/Math.js 362

pi/2

static constant Cesium.Math.RADIANS_PER_ARCSECOND : Number
Core/Math.js 434

The number of radians in an arc second.

static constant Cesium.Math.RADIANS_PER_DEGREE : Number
Core/Math.js 418

The number of radians in a degree.

static constant Cesium.Math.SIXTY_FOUR_KILOBYTES : Number
Core/Math.js 191

64 * 1024

static constant Cesium.Math.SOLAR_RADIUS : Number
Core/Math.js 175

Radius of the sun in meters: 6.955e8

static constant Cesium.Math.THREE_PI_OVER_TWO : Number
Core/Math.js 394

3pi/2

static constant Cesium.Math.TWO_PI : Number
Core/Math.js 402

2pi

Methods

static Cesium.Math.acosClamped(value) → Number
Core/Math.js 970

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.

static Cesium.Math.asinClamped(value) → Number
Core/Math.js 987

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.

static Cesium.Math.cbrt(number) → Number
Core/Math.js 1043

Finds the cube root of a number. Returns NaN if number is not provided.
Name Type Description
number Number optional The number.
Returns:
The result.

static Cesium.Math.chordLength(angle, radius) → Number
Core/Math.js 1003

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.

static Cesium.Math.clamp(value, min, max) → Number
Core/Math.js 905

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.

static Cesium.Math.clampToLatitudeRange(angle) → Number
Core/Math.js 505

Convenience function that clamps a latitude value, in radians, to the range [-Math.PI/2, Math.PI/2). Useful for sanitizing data before use in objects requiring correct range.
Name Type Description
angle Number The latitude value, in radians, to clamp to the range [-Math.PI/2, Math.PI/2).
Returns:
The latitude value clamped to the range [-Math.PI/2, Math.PI/2).
Example:
// Clamp 108 degrees latitude to 90 degrees latitude
const latitude = Cesium.Math.clampToLatitudeRange(Cesium.Math.toRadians(108.0));

static Cesium.Math.convertLongitudeRange(angle) → Number
Core/Math.js 474

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
const longitude = Cesium.Math.convertLongitudeRange(Cesium.Math.toRadians(270.0));

static Cesium.Math.cosh(value) → Number
Core/Math.js 321

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.

static Cesium.Math.equalsEpsilon(left, right, relativeEpsilon, absoluteEpsilon) → Boolean
Core/Math.js 612

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 0 optional 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:
const a = Cesium.Math.equalsEpsilon(0.0, 0.01, Cesium.Math.EPSILON2); // true
const b = Cesium.Math.equalsEpsilon(0.0, 0.1, Cesium.Math.EPSILON2);  // false
const c = Cesium.Math.equalsEpsilon(3699175.1634344, 3699175.2, Cesium.Math.EPSILON7); // true
const d = Cesium.Math.equalsEpsilon(3699175.1634344, 3699175.2, Cesium.Math.EPSILON9); // false

static Cesium.Math.factorial(n) → Number
Core/Math.js 755

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
const computedFactorial = Cesium.Math.factorial(7);
See:

static Cesium.Math.fastApproximateAtan(x) → Number
Core/Math.js 1079

Computes a fast approximation of Atan for input in the range [-1, 1]. Based on Michal Drobot's approximation from ShaderFastLibs, which in turn is based on "Efficient approximations for the arctangent function," Rajan, S. Sichun Wang Inkol, R. Joyal, A., May 2006. Adapted from ShaderFastLibs under MIT License.
Name Type Description
x Number An input number in the range [-1, 1]
Returns:
An approximation of atan(x)

static Cesium.Math.fastApproximateAtan2(x, y) → Number
Core/Math.js 1096

Computes a fast approximation of Atan2(x, y) for arbitrary input scalars. Range reduction math based on nvidia's cg reference implementation: http://developer.download.nvidia.com/cg/atan2.html
Name Type Description
x Number An input number that isn't zero if y is zero.
y Number An input number that isn't zero if x is zero.
Returns:
An approximation of atan2(x, y)

static Cesium.Math.fromSNorm(value, rangeMaximum) → Number
Core/Math.js 252

Converts a SNORM value in the range [0, rangeMaximum] to a scalar in the range [-1.0, 1.0].
Name Type Default Description
value Number SNORM value in the range [0, rangeMaximum]
rangeMaximum Number 255 optional The maximum value in the SNORM range, 255 by default.
Returns:
Scalar in the range [-1.0, 1.0].
See:
  • CesiumMath.toSNorm

static Cesium.Math.greaterThan(left, right, absoluteEpsilon) → Boolean
Core/Math.js 698

Determines if the left value is greater the right value. If the two values are within absoluteEpsilon of each other, they are considered equal and this function returns false.
Name Type Description
left Number The first number to compare.
right Number The second number to compare.
absoluteEpsilon Number The absolute epsilon to use in comparison.
Returns:
true if left is greater than right by more than absoluteEpsilon. false if left is less or if the two values are nearly equal.

static Cesium.Math.greaterThanOrEquals(left, right, absoluteEpsilon) → Boolean
Core/Math.js 723

Determines if the left value is greater than or equal to the right value. If the two values are within absoluteEpsilon of each other, they are considered equal and this function returns true.
Name Type Description
left Number The first number to compare.
right Number The second number to compare.
absoluteEpsilon Number The absolute epsilon to use in comparison.
Returns:
true if left is greater than right or if the the values are nearly equal.

static Cesium.Math.incrementWrap(n, maximumValue, minimumValue) → Number
Core/Math.js 790

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:
const n = Cesium.Math.incrementWrap(5, 10, 0); // returns 6
const m = Cesium.Math.incrementWrap(10, 10, 0); // returns 0

static Cesium.Math.isPowerOfTwo(n) → Boolean
Core/Math.js 822

Determines if a non-negative integer is a power of two. The maximum allowed input is (2^32)-1 due to 32-bit bitwise operator limitation in Javascript.
Name Type Description
n Number The integer to test in the range [0, (2^32)-1].
Returns:
true if the number if a power of two; otherwise, false.
Throws:
Example:
const t = Cesium.Math.isPowerOfTwo(16); // true
const f = Cesium.Math.isPowerOfTwo(20); // false

static Cesium.Math.lerp(p, q, time) → Number
Core/Math.js 336

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:
const n = Cesium.Math.lerp(0.0, 2.0, 0.5); // returns 1.0

static Cesium.Math.lessThan(left, right, absoluteEpsilon) → Boolean
Core/Math.js 647

Determines if the left value is less than the right value. If the two values are within absoluteEpsilon of each other, they are considered equal and this function returns false.
Name Type Description
left Number The first number to compare.
right Number The second number to compare.
absoluteEpsilon Number The absolute epsilon to use in comparison.
Returns:
true if left is less than right by more than absoluteEpsilon. false if left is greater or if the two values are nearly equal.

static Cesium.Math.lessThanOrEquals(left, right, absoluteEpsilon) → Boolean
Core/Math.js 672

Determines if the left value is less than or equal to the right value. If the two values are within absoluteEpsilon of each other, they are considered equal and this function returns true.
Name Type Description
left Number The first number to compare.
right Number The second number to compare.
absoluteEpsilon Number The absolute epsilon to use in comparison.
Returns:
true if left is less than right or if the the values are nearly equal.

static Cesium.Math.log2(number) → Number
Core/Math.js 1056

Finds the base 2 logarithm of a number.
Name Type Description
number Number The number.
Returns:
The result.

static Cesium.Math.logBase(number, base) → Number
Core/Math.js 1022

Finds the logarithm of a number to a base.
Name Type Description
number Number The number.
base Number The base.
Returns:
The result.

static Cesium.Math.mod(m, n) → Number
Core/Math.js 573

The modulo operation that also works for negative dividends.
Name Type Description
m Number The dividend.
n Number The divisor.
Returns:
The remainder.

static Cesium.Math.negativePiToPi(angle) → Number
Core/Math.js 525

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].

static Cesium.Math.nextPowerOfTwo(n) → Number
Core/Math.js 845

Computes the next power-of-two integer greater than or equal to the provided non-negative integer. The maximum allowed input is 2^31 due to 32-bit bitwise operator limitation in Javascript.
Name Type Description
n Number The integer to test in the range [0, 2^31].
Returns:
The next power-of-two integer.
Throws:
Example:
const n = Cesium.Math.nextPowerOfTwo(29); // 32
const m = Cesium.Math.nextPowerOfTwo(32); // 32

static Cesium.Math.nextRandomNumber() → Number
Core/Math.js 947

Generates a random floating point 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:

static Cesium.Math.normalize(value, rangeMinimum, rangeMaximum) → Number
Core/Math.js 266

Converts a scalar value in the range [rangeMinimum, rangeMaximum] to a scalar in the range [0.0, 1.0]
Name Type Description
value Number The scalar value in the range [rangeMinimum, rangeMaximum]
rangeMinimum Number The minimum value in the mapped range.
rangeMaximum Number The maximum value in the mapped range.
Returns:
A scalar value, where rangeMinimum maps to 0.0 and rangeMaximum maps to 1.0.

static Cesium.Math.previousPowerOfTwo(n) → Number
Core/Math.js 877

Computes the previous power-of-two integer less than or equal to the provided non-negative integer. The maximum allowed input is (2^32)-1 due to 32-bit bitwise operator limitation in Javascript.
Name Type Description
n Number The integer to test in the range [0, (2^32)-1].
Returns:
The previous power-of-two integer.
Throws:
Example:
const n = Cesium.Math.previousPowerOfTwo(29); // 16
const m = Cesium.Math.previousPowerOfTwo(32); // 32

static Cesium.Math.randomBetween(min, max) → Number
Core/Math.js 958

Generates a random number between two numbers.
Name Type Description
min Number The minimum value.
max Number The maximum value.
Returns:
A random number between the min and max.

static Cesium.Math.setRandomNumberSeed(seed)
Core/Math.js 928

Sets the seed used by the random number generator in CesiumMath#nextRandomNumber.
Name Type Description
seed Number An integer used as the seed.

static Cesium.Math.sign(value) → Number
Core/Math.js 209

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.

static Cesium.Math.signNotZero(value) → Number
Core/Math.js 225

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.

static Cesium.Math.sinh(value) → Number
Core/Math.js 296

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.

static Cesium.Math.toDegrees(radians) → Number
Core/Math.js 455

Converts radians to degrees.
Name Type Description
radians Number The angle to convert in radians.
Returns:
The corresponding angle in degrees.

static Cesium.Math.toRadians(degrees) → Number
Core/Math.js 441

Converts degrees to radians.
Name Type Description
degrees Number The angle to convert in degrees.
Returns:
The corresponding angle in radians.

static Cesium.Math.toSNorm(value, rangeMaximum) → Number
Core/Math.js 237

Converts a scalar value in the range [-1.0, 1.0] to a SNORM in the range [0, rangeMaximum]
Name Type Default Description
value Number The scalar value in the range [-1.0, 1.0]
rangeMaximum Number 255 optional The maximum value in the mapped range, 255 by default.
Returns:
A SNORM value, where 0 maps to -1.0 and rangeMaximum maps to 1.0.
See:
  • CesiumMath.fromSNorm

static Cesium.Math.zeroToTwoPi(angle) → Number
Core/Math.js 545

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].