std/math

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Constructive mathematics is naturally typed. -- Simon Thompson

Basic math routines for Nim.

Note that the trigonometric functions naturally operate on radians. The helper functions degToRad and radToDeg provide conversion between radians and degrees.

Example:

import std/math
from std/fenv import epsilon
from std/random import rand

proc generateGaussianNoise(mu: float = 0.0, sigma: float = 1.0): (float, float) =
  # Generates values from a normal distribution.
  # Translated from https://en.wikipedia.org/wiki/Box%E2%80%93Muller_transform#Implementation.
  var u1: float
  var u2: float
  while true:
    u1 = rand(1.0)
    u2 = rand(1.0)
    if u1 > epsilon(float): break
  let mag = sigma * sqrt(-2 * ln(u1))
  let z0 = mag * cos(2 * PI * u2) + mu
  let z1 = mag * sin(2 * PI * u2) + mu
  (z0, z1)

echo generateGaussianNoise()
This module is available for the JavaScript target.

See also

  • complex module for complex numbers and their mathematical operations
  • rationals module for rational numbers and their mathematical operations
  • fenv module for handling of floating-point rounding and exceptions (overflow, zero-divide, etc.)
  • random module for a fast and tiny random number generator
  • stats module for statistical analysis
  • strformat module for formatting floats for printing
  • system module for some very basic and trivial math operators (shr, shl, xor, clamp, etc.)

Types

FloatClass = enum
  fcNormal,                 ## value is an ordinary nonzero floating point value
  fcSubnormal,              ## value is a subnormal (a very small) floating point value
  fcZero,                   ## value is zero
  fcNegZero,                ## value is the negative zero
  fcNan,                    ## value is Not a Number (NaN)
  fcInf,                    ## value is positive infinity
  fcNegInf                   ## value is negative infinity
Describes the class a floating point value belongs to. This is the type that is returned by the classify func. Source   Edit  

Consts

E = 2.718281828459045
Euler's number. Source   Edit  
MaxFloat32Precision = 8
Maximum number of meaningful digits after the decimal point for Nim's float32 type. Source   Edit  
MaxFloat64Precision = 16
Maximum number of meaningful digits after the decimal point for Nim's float64 type. Source   Edit  
MaxFloatPrecision = 16
Maximum number of meaningful digits after the decimal point for Nim's float type. Source   Edit  
MinFloatNormal = 2.225073858507201e-308
Smallest normal number for Nim's float type (= 2^-1022). Source   Edit  
PI = 3.141592653589793
The circle constant PI (Ludolph's number). Source   Edit  
TAU = 6.283185307179586
The circle constant TAU (= 2 * PI). Source   Edit  

Procs

func `^`[T: SomeNumber](x: T; y: Natural): T

Computes x to the power of y.

The exponent y must be non-negative, use pow for negative exponents.

See also:

Example:

doAssert -3 ^ 0 == 1
doAssert -3 ^ 1 == -3
doAssert -3 ^ 2 == 9
Source   Edit  
func almostEqual[T: SomeFloat](x, y: T; unitsInLastPlace: Natural = 4): bool {.
    inline.}

Checks if two float values are almost equal, using the machine epsilon.

unitsInLastPlace is the max number of units in the last place difference tolerated when comparing two numbers. The larger the value, the more error is allowed. A 0 value means that two numbers must be exactly the same to be considered equal.

The machine epsilon has to be scaled to the magnitude of the values used and multiplied by the desired precision in ULPs unless the difference is subnormal.

Example:

doAssert almostEqual(PI, 3.14159265358979)
doAssert almostEqual(Inf, Inf)
doAssert not almostEqual(NaN, NaN)
Source   Edit  
func arccos(x: float32): float32 {.importc: "acosf", header: "<math.h>",
                                   ...raises: [], tags: [], forbids: [].}
Source   Edit  
func arccos(x: float64): float64 {.importc: "acos", header: "<math.h>",
                                   ...raises: [], tags: [], forbids: [].}

Computes the arc cosine of x.

See also:

Example:

doAssert almostEqual(radToDeg(arccos(0.0)), 90.0)
doAssert almostEqual(radToDeg(arccos(1.0)), 0.0)
Source   Edit  
func arccosh(x: float32): float32 {.importc: "acoshf", header: "<math.h>",
                                    ...raises: [], tags: [], forbids: [].}
Source   Edit  
func arccosh(x: float64): float64 {.importc: "acosh", header: "<math.h>",
                                    ...raises: [], tags: [], forbids: [].}

Computes the inverse hyperbolic cosine of x.

See also:

Source   Edit  
func arccot[T: float32 | float64](x: T): T
Computes the inverse cotangent of x (arctan(1/x)). Source   Edit  
func arccoth[T: float32 | float64](x: T): T
Computes the inverse hyperbolic cotangent of x (arctanh(1/x)). Source   Edit  
func arccsc[T: float32 | float64](x: T): T
Computes the inverse cosecant of x (arcsin(1/x)). Source   Edit  
func arccsch[T: float32 | float64](x: T): T
Computes the inverse hyperbolic cosecant of x (arcsinh(1/x)). Source   Edit  
func arcsec[T: float32 | float64](x: T): T
Computes the inverse secant of x (arccos(1/x)). Source   Edit  
func arcsech[T: float32 | float64](x: T): T
Computes the inverse hyperbolic secant of x (arccosh(1/x)). Source   Edit  
func arcsin(x: float32): float32 {.importc: "asinf", header: "<math.h>",
                                   ...raises: [], tags: [], forbids: [].}
Source   Edit  
func arcsin(x: float64): float64 {.importc: "asin", header: "<math.h>",
                                   ...raises: [], tags: [], forbids: [].}

Computes the arc sine of x.

See also:

Example:

doAssert almostEqual(radToDeg(arcsin(0.0)), 0.0)
doAssert almostEqual(radToDeg(arcsin(1.0)), 90.0)
Source   Edit  
func arcsinh(x: float32): float32 {.importc: "asinhf", header: "<math.h>",
                                    ...raises: [], tags: [], forbids: [].}
Source   Edit  
func arcsinh(x: float64): float64 {.importc: "asinh", header: "<math.h>",
                                    ...raises: [], tags: [], forbids: [].}

Computes the inverse hyperbolic sine of x.

See also:

Source   Edit  
func arctan(x: float32): float32 {.importc: "atanf", header: "<math.h>",
                                   ...raises: [], tags: [], forbids: [].}
Source   Edit  
func arctan(x: float64): float64 {.importc: "atan", header: "<math.h>",
                                   ...raises: [], tags: [], forbids: [].}

Calculate the arc tangent of x.

See also:

Example:

doAssert almostEqual(arctan(1.0), 0.7853981633974483)
doAssert almostEqual(radToDeg(arctan(1.0)), 45.0)
Source   Edit  
func arctan2(y, x: float32): float32 {.importc: "atan2f", header: "<math.h>",
                                       ...raises: [], tags: [], forbids: [].}
Source   Edit  
func arctan2(y, x: float64): float64 {.importc: "atan2", header: "<math.h>",
                                       ...raises: [], tags: [], forbids: [].}

Calculate the arc tangent of y/x.

It produces correct results even when the resulting angle is near PI/2 or -PI/2 (x near 0).

See also:

Example:

doAssert almostEqual(arctan2(1.0, 0.0), PI / 2.0)
doAssert almostEqual(radToDeg(arctan2(1.0, 0.0)), 90.0)
Source   Edit  
func arctanh(x: float32): float32 {.importc: "atanhf", header: "<math.h>",
                                    ...raises: [], tags: [], forbids: [].}
Source   Edit  
func arctanh(x: float64): float64 {.importc: "atanh", header: "<math.h>",
                                    ...raises: [], tags: [], forbids: [].}

Computes the inverse hyperbolic tangent of x.

See also:

Source   Edit  
func binom(n, k: int): int {....raises: [], tags: [], forbids: [].}
Computes the binomial coefficient.

Example:

doAssert binom(6, 2) == 15
doAssert binom(-6, 2) == 1
doAssert binom(6, 0) == 1
Source   Edit  
func cbrt(x: float32): float32 {.importc: "cbrtf", header: "<math.h>",
                                 ...raises: [], tags: [], forbids: [].}
Source   Edit  
func cbrt(x: float64): float64 {.importc: "cbrt", header: "<math.h>",
                                 ...raises: [], tags: [], forbids: [].}

Computes the cube root of x.

See also:

Example:

doAssert almostEqual(cbrt(8.0), 2.0)
doAssert almostEqual(cbrt(2.197), 1.3)
doAssert almostEqual(cbrt(-27.0), -3.0)
Source   Edit  
func ceil(x: float32): float32 {.importc: "ceilf", header: "<math.h>",
                                 ...raises: [], tags: [], forbids: [].}
Source   Edit  
func ceil(x: float64): float64 {.importc: "ceil", header: "<math.h>",
                                 ...raises: [], tags: [], forbids: [].}

Computes the ceiling function (i.e. the smallest integer not smaller than x).

See also:

Example:

doAssert ceil(2.1)  == 3.0
doAssert ceil(2.9)  == 3.0
doAssert ceil(-2.1) == -2.0
Source   Edit  
func ceilDiv[T: SomeInteger](x, y: T): T {.inline.}

Ceil division is conceptually defined as ceil(x / y).

Assumes x >= 0 and y > 0 (and x + y - 1 <= high(T) if T is SomeUnsignedInt).

This is different from the system.div operator, which works like trunc(x / y). That is, div rounds towards 0 and ceilDiv rounds up.

This function has the above input limitation, because that allows the compiler to generate faster code and it is rarely used with negative values or unsigned integers close to high(T)/2. If you need a ceilDiv that works with any input, see: https://github.com/demotomohiro/divmath.

See also:

Example:

assert ceilDiv(12, 3) ==  4
assert ceilDiv(13, 3) ==  5
Source   Edit  
func clamp[T](val: T; bounds: Slice[T]): T {.inline.}
Like system.clamp, but takes a slice, so you can easily clamp within a range.

Example:

assert clamp(10, 1 .. 5) == 5
assert clamp(1, 1 .. 3) == 1
type A = enum a0, a1, a2, a3, a4, a5
assert a1.clamp(a2..a4) == a2
assert clamp((3, 0), (1, 0) .. (2, 9)) == (2, 9)
doAssertRaises(AssertionDefect): discard clamp(1, 3..2) # invalid bounds
Source   Edit  
func classify(x: float): FloatClass {....raises: [], tags: [], forbids: [].}

Classifies a floating point value.

Returns x's class as specified by the FloatClass enum. Doesn't work with --passc:-ffast-math.

Example:

doAssert classify(0.3) == fcNormal
doAssert classify(0.0) == fcZero
doAssert classify(0.3 / 0.0) == fcInf
doAssert classify(-0.3 / 0.0) == fcNegInf
doAssert classify(5.0e-324) == fcSubnormal
Source   Edit  
func copySign[T: SomeFloat](x, y: T): T {.inline.}
Returns a value with the magnitude of x and the sign of y; this works even if x or y are NaN, infinity or zero, all of which can carry a sign.

Example:

doAssert copySign(10.0, 1.0) == 10.0
doAssert copySign(10.0, -1.0) == -10.0
doAssert copySign(-Inf, -0.0) == -Inf
doAssert copySign(NaN, 1.0).isNaN
doAssert copySign(1.0, copySign(NaN, -1.0)) == -1.0
Source   Edit  
func cos(x: float32): float32 {.importc: "cosf", header: "<math.h>", ...raises: [],
                                tags: [], forbids: [].}
Source   Edit  
func cos(x: float64): float64 {.importc: "cos", header: "<math.h>", ...raises: [],
                                tags: [], forbids: [].}

Computes the cosine of x.

See also:

Example:

doAssert almostEqual(cos(2 * PI), 1.0)
doAssert almostEqual(cos(degToRad(60.0)), 0.5)
Source   Edit  
func cosh(x: float32): float32 {.importc: "coshf", header: "<math.h>",
                                 ...raises: [], tags: [], forbids: [].}
Source   Edit  
func cosh(x: float64): float64 {.importc: "cosh", header: "<math.h>",
                                 ...raises: [], tags: [], forbids: [].}

Computes the hyperbolic cosine of x.

See also:

Example:

doAssert almostEqual(cosh(0.0), 1.0)
doAssert almostEqual(cosh(1.0), 1.543080634815244)
Source   Edit  
func cot[T: float32 | float64](x: T): T
Computes the cotangent of x (1/tan(x)). Source   Edit  
func coth[T: float32 | float64](x: T): T
Computes the hyperbolic cotangent of x (1/tanh(x)). Source   Edit  
func csc[T: float32 | float64](x: T): T
Computes the cosecant of x (1/sin(x)). Source   Edit  
func csch[T: float32 | float64](x: T): T
Computes the hyperbolic cosecant of x (1/sinh(x)). Source   Edit  
func cumsum[T](x: var openArray[T])

Transforms x in-place (must be declared as var) into its cumulative (aka prefix) summation.

See also:

Example:

var a = [1, 2, 3, 4]
cumsum(a)
doAssert a == @[1, 3, 6, 10]
Source   Edit  
func cumsummed[T](x: openArray[T]): seq[T]

Returns the cumulative (aka prefix) summation of x.

If x is empty, @[] is returned.

See also:

Example:

doAssert cumsummed([1, 2, 3, 4]) == @[1, 3, 6, 10]
Source   Edit  
func degToRad[T: float32 | float64](d: T): T {.inline.}

Converts from degrees to radians.

See also:

Example:

doAssert almostEqual(degToRad(180.0), PI)
Source   Edit  
func divmod[T: SomeInteger](x, y: T): (T, T) {.inline.}
Specialized instructions for computing both division and modulus. Return structure is: (quotient, remainder)

Example:

doAssert divmod(5, 2) == (2, 1)
doAssert divmod(5, -3) == (-1, 2)
Source   Edit  
func erf(x: float32): float32 {.importc: "erff", header: "<math.h>", ...raises: [],
                                tags: [], forbids: [].}
Source   Edit  
func erf(x: float64): float64 {.importc: "erf", header: "<math.h>", ...raises: [],
                                tags: [], forbids: [].}

Computes the error function for x.

Note: Not available for the JS backend.

Source   Edit  
func erfc(x: float32): float32 {.importc: "erfcf", header: "<math.h>",
                                 ...raises: [], tags: [], forbids: [].}
Source   Edit  
func erfc(x: float64): float64 {.importc: "erfc", header: "<math.h>",
                                 ...raises: [], tags: [], forbids: [].}

Computes the complementary error function for x.

Note: Not available for the JS backend.

Source   Edit  
func euclDiv[T: SomeInteger](x, y: T): T
Returns euclidean division of x by y.

Example:

doAssert euclDiv(13, 3) == 4
doAssert euclDiv(-13, 3) == -5
doAssert euclDiv(13, -3) == -4
doAssert euclDiv(-13, -3) == 5
Source   Edit  
func euclMod[T: SomeNumber](x, y: T): T
Returns euclidean modulo of x by y. euclMod(x, y) is non-negative.

Example:

doAssert euclMod(13, 3) == 1
doAssert euclMod(-13, 3) == 2
doAssert euclMod(13, -3) == 1
doAssert euclMod(-13, -3) == 2
Source   Edit  
func exp(x: float32): float32 {.importc: "expf", header: "<math.h>", ...raises: [],
                                tags: [], forbids: [].}
Source   Edit  
func exp(x: float64): float64 {.importc: "exp", header: "<math.h>", ...raises: [],
                                tags: [], forbids: [].}

Computes the exponential function of x (e^x).

See also:

Example:

doAssert almostEqual(exp(1.0), E)
doAssert almostEqual(ln(exp(4.0)), 4.0)
doAssert almostEqual(exp(0.0), 1.0)
Source   Edit  
func fac(n: int): int {....raises: [], tags: [], forbids: [].}

Computes the factorial of a non-negative integer n.

See also:

Example:

doAssert fac(0) == 1
doAssert fac(4) == 24
doAssert fac(10) == 3628800
Source   Edit  
func floor(x: float32): float32 {.importc: "floorf", header: "<math.h>",
                                  ...raises: [], tags: [], forbids: [].}
Source   Edit  
func floor(x: float64): float64 {.importc: "floor", header: "<math.h>",
                                  ...raises: [], tags: [], forbids: [].}

Computes the floor function (i.e. the largest integer not greater than x).

See also:

Example:

doAssert floor(2.1)  == 2.0
doAssert floor(2.9)  == 2.0
doAssert floor(-3.5) == -4.0
Source   Edit  
func floorDiv[T: SomeInteger](x, y: T): T

Floor division is conceptually defined as floor(x / y).

This is different from the system.div operator, which is defined as trunc(x / y). That is, div rounds towards 0 and floorDiv rounds down.

See also:

Example:

doAssert floorDiv( 13,  3) ==  4
doAssert floorDiv(-13,  3) == -5
doAssert floorDiv( 13, -3) == -5
doAssert floorDiv(-13, -3) ==  4
Source   Edit  
func floorMod[T: SomeNumber](x, y: T): T

Floor modulo is conceptually defined as x - (floorDiv(x, y) * y).

This func behaves the same as the % operator in Python.

See also:

Example:

doAssert floorMod( 13,  3) ==  1
doAssert floorMod(-13,  3) ==  2
doAssert floorMod( 13, -3) == -2
doAssert floorMod(-13, -3) == -1
Source   Edit  
func frexp[T: float32 | float64](x: T): tuple[frac: T, exp: int] {.inline.}
Splits x into a normalized fraction frac and an integral power of 2 exp, such that abs(frac) in 0.5..<1 and x == frac * 2 ^ exp, except for special cases shown below.

Example:

doAssert frexp(8.0) == (0.5, 4)
doAssert frexp(-8.0) == (-0.5, 4)
doAssert frexp(0.0) == (0.0, 0)

# special cases:
when sizeof(int) == 8:
  doAssert frexp(-0.0).frac.signbit # signbit preserved for +-0
  doAssert frexp(Inf).frac == Inf # +- Inf preserved
  doAssert frexp(NaN).frac.isNaN
Source   Edit  
func frexp[T: float32 | float64](x: T; exponent: var int): T {.inline.}
Overload of frexp that calls (result, exponent) = frexp(x).

Example:

var x: int
doAssert frexp(5.0, x) == 0.625
doAssert x == 3
Source   Edit  
func gamma(x: float32): float32 {.importc: "tgammaf", header: "<math.h>",
                                  ...raises: [], tags: [], forbids: [].}
Source   Edit  
func gamma(x: float64): float64 {.importc: "tgamma", header: "<math.h>",
                                  ...raises: [], tags: [], forbids: [].}

Computes the gamma function for x.

Note: Not available for the JS backend.

See also:

  • lgamma func for the natural logarithm of the gamma function

Example:

doAssert almostEqual(gamma(1.0), 1.0)
doAssert almostEqual(gamma(4.0), 6.0)
doAssert almostEqual(gamma(11.0), 3628800.0)
Source   Edit  
func gcd(x, y: SomeInteger): SomeInteger

Computes the greatest common (positive) divisor of x and y, using the binary GCD (aka Stein's) algorithm.

See also:

Example:

doAssert gcd(12, 8) == 4
doAssert gcd(17, 63) == 1
Source   Edit  
func gcd[T](x, y: T): T

Computes the greatest common (positive) divisor of x and y.

Note that for floats, the result cannot always be interpreted as "greatest decimal z such that z*N == x and z*M == y where N and M are positive integers".

See also:

Example:

doAssert gcd(13.5, 9.0) == 4.5
Source   Edit  
func gcd[T](x: openArray[T]): T

Computes the greatest common (positive) divisor of the elements of x.

See also:

  • gcd func for a version with two arguments

Example:

doAssert gcd(@[13.5, 9.0]) == 4.5
Source   Edit  
func hypot(x, y: float32): float32 {.importc: "hypotf", header: "<math.h>",
                                     ...raises: [], tags: [], forbids: [].}
Source   Edit  
func hypot(x, y: float64): float64 {.importc: "hypot", header: "<math.h>",
                                     ...raises: [], tags: [], forbids: [].}
Computes the length of the hypotenuse of a right-angle triangle with x as its base and y as its height. Equivalent to sqrt(x*x + y*y).

Example:

doAssert almostEqual(hypot(3.0, 4.0), 5.0)
Source   Edit  
func isNaN(x: SomeFloat): bool {.inline.}
Returns whether x is a NaN, more efficiently than via classify(x) == fcNan. Works even with --passc:-ffast-math.

Example:

doAssert NaN.isNaN
doAssert not Inf.isNaN
doAssert not isNaN(3.1415926)
Source   Edit  
func isPowerOfTwo(x: int): bool {....raises: [], tags: [], forbids: [].}

Returns true, if x is a power of two, false otherwise.

Zero and negative numbers are not a power of two.

See also:

Example:

doAssert isPowerOfTwo(16)
doAssert not isPowerOfTwo(5)
doAssert not isPowerOfTwo(0)
doAssert not isPowerOfTwo(-16)
Source   Edit  
func lcm[T](x, y: T): T

Computes the least common multiple of x and y.

See also:

Example:

doAssert lcm(24, 30) == 120
doAssert lcm(13, 39) == 39
Source   Edit  
func lcm[T](x: openArray[T]): T

Computes the least common multiple of the elements of x.

See also:

  • lcm func for a version with two arguments

Example:

doAssert lcm(@[24, 30]) == 120
Source   Edit  
func lgamma(x: float32): float32 {.importc: "lgammaf", header: "<math.h>",
                                   ...raises: [], tags: [], forbids: [].}
Source   Edit  
func lgamma(x: float64): float64 {.importc: "lgamma", header: "<math.h>",
                                   ...raises: [], tags: [], forbids: [].}

Computes the natural logarithm of the gamma function for x.

Note: Not available for the JS backend.

See also:

Source   Edit  
func ln(x: float32): float32 {.importc: "logf", header: "<math.h>", ...raises: [],
                               tags: [], forbids: [].}
Source   Edit  
func ln(x: float64): float64 {.importc: "log", header: "<math.h>", ...raises: [],
                               tags: [], forbids: [].}

Computes the natural logarithm of x.

See also:

Example:

doAssert almostEqual(ln(exp(4.0)), 4.0)
doAssert almostEqual(ln(1.0), 0.0)
doAssert almostEqual(ln(0.0), -Inf)
doAssert ln(-7.0).isNaN
Source   Edit  
func log[T: SomeFloat](x, base: T): T

Computes the logarithm of x to base base.

See also:

Example:

doAssert almostEqual(log(9.0, 3.0), 2.0)
doAssert almostEqual(log(0.0, 2.0), -Inf)
doAssert log(-7.0, 4.0).isNaN
doAssert log(8.0, -2.0).isNaN
Source   Edit  
func log2(x: float32): float32 {.importc: "log2f", header: "<math.h>",
                                 ...raises: [], tags: [], forbids: [].}
Source   Edit  
func log2(x: float64): float64 {.importc: "log2", header: "<math.h>",
                                 ...raises: [], tags: [], forbids: [].}

Computes the binary logarithm (base 2) of x.

See also:

Example:

doAssert almostEqual(log2(8.0), 3.0)
doAssert almostEqual(log2(1.0), 0.0)
doAssert almostEqual(log2(0.0), -Inf)
doAssert log2(-2.0).isNaN
Source   Edit  
func log10(x: float32): float32 {.importc: "log10f", header: "<math.h>",
                                  ...raises: [], tags: [], forbids: [].}
Source   Edit  
func log10(x: float64): float64 {.importc: "log10", header: "<math.h>",
                                  ...raises: [], tags: [], forbids: [].}

Computes the common logarithm (base 10) of x.

See also:

Example:

doAssert almostEqual(log10(100.0) , 2.0)
doAssert almostEqual(log10(0.0), -Inf)
doAssert log10(-100.0).isNaN
Source   Edit  
func `mod`(x, y: float32): float32 {.importc: "fmodf", header: "<math.h>",
                                     ...raises: [], tags: [], forbids: [].}
Source   Edit  
func `mod`(x, y: float64): float64 {.importc: "fmod", header: "<math.h>",
                                     ...raises: [], tags: [], forbids: [].}

Computes the modulo operation for float values (the remainder of x divided by y).

See also:

Example:

doAssert  6.5 mod  2.5 ==  1.5
doAssert -6.5 mod  2.5 == -1.5
doAssert  6.5 mod -2.5 ==  1.5
doAssert -6.5 mod -2.5 == -1.5
Source   Edit  
func nextPowerOfTwo(x: int): int {....raises: [], tags: [], forbids: [].}

Returns x rounded up to the nearest power of two.

Zero and negative numbers get rounded up to 1.

See also:

Example:

doAssert nextPowerOfTwo(16) == 16
doAssert nextPowerOfTwo(5) == 8
doAssert nextPowerOfTwo(0) == 1
doAssert nextPowerOfTwo(-16) == 1
Source   Edit  
func pow(x, y: float32): float32 {.importc: "powf", header: "<math.h>",
                                   ...raises: [], tags: [], forbids: [].}
Source   Edit  
func pow(x, y: float64): float64 {.importc: "pow", header: "<math.h>",
                                   ...raises: [], tags: [], forbids: [].}

Computes x raised to the power of y.

To compute the power between integers (e.g. 2^6), use the ^ func.

See also:

Example:

doAssert almostEqual(pow(100, 1.5), 1000.0)
doAssert almostEqual(pow(16.0, 0.5), 4.0)
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func prod[T](x: openArray[T]): T

Computes the product of the elements in x.

If x is empty, 1 is returned.

See also:

Example:

doAssert prod([1, 2, 3, 4]) == 24
doAssert prod([-4, 3, 5]) == -60
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func radToDeg[T: float32 | float64](d: T): T {.inline.}

Converts from radians to degrees.

See also:

Example:

doAssert almostEqual(radToDeg(2 * PI), 360.0)
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func round(x: float32): float32 {.importc: "roundf", header: "<math.h>",
                                  ...raises: [], tags: [], forbids: [].}
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func round(x: float64): float64 {.importc: "round", header: "<math.h>",
                                  ...raises: [], tags: [], forbids: [].}

Rounds a float to zero decimal places.

Used internally by the round func when the specified number of places is 0.

See also:

Example:

doAssert round(3.4) == 3.0
doAssert round(3.5) == 4.0
doAssert round(4.5) == 5.0
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func round[T: float32 | float64](x: T; places: int): T

Decimal rounding on a binary floating point number.

This function is NOT reliable. Floating point numbers cannot hold non integer decimals precisely. If places is 0 (or omitted), round to the nearest integral value following normal mathematical rounding rules (e.g. round(54.5) -> 55.0). If places is greater than 0, round to the given number of decimal places, e.g. round(54.346, 2) -> 54.350000000000001421…. If places is negative, round to the left of the decimal place, e.g. round(537.345, -1) -> 540.0.

Example:

doAssert round(PI, 2) == 3.14
doAssert round(PI, 4) == 3.1416
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func sec[T: float32 | float64](x: T): T
Computes the secant of x (1/cos(x)). Source   Edit  
func sech[T: float32 | float64](x: T): T
Computes the hyperbolic secant of x (1/cosh(x)). Source   Edit  
func sgn[T: SomeNumber](x: T): int {.inline.}

Sign function.

Returns:

  • -1 for negative numbers and NegInf,
  • 1 for positive numbers and Inf,
  • 0 for positive zero, negative zero and NaN

Example:

doAssert sgn(5) == 1
doAssert sgn(0) == 0
doAssert sgn(-4.1) == -1
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proc signbit(x: SomeFloat): bool {.inline.}
Returns true if x is negative, false otherwise.

Example:

doAssert not signbit(0.0)
doAssert signbit(-0.0)
doAssert signbit(-0.1)
doAssert not signbit(0.1)
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func sin(x: float32): float32 {.importc: "sinf", header: "<math.h>", ...raises: [],
                                tags: [], forbids: [].}
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func sin(x: float64): float64 {.importc: "sin", header: "<math.h>", ...raises: [],
                                tags: [], forbids: [].}

Computes the sine of x.

See also:

Example:

doAssert almostEqual(sin(PI / 6), 0.5)
doAssert almostEqual(sin(degToRad(90.0)), 1.0)
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func sinh(x: float32): float32 {.importc: "sinhf", header: "<math.h>",
                                 ...raises: [], tags: [], forbids: [].}
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func sinh(x: float64): float64 {.importc: "sinh", header: "<math.h>",
                                 ...raises: [], tags: [], forbids: [].}

Computes the hyperbolic sine of x.

See also:

Example:

doAssert almostEqual(sinh(0.0), 0.0)
doAssert almostEqual(sinh(1.0), 1.175201193643801)
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func splitDecimal[T: float32 | float64](x: T): tuple[intpart: T, floatpart: T]

Breaks x into an integer and a fractional part.

Returns a tuple containing intpart and floatpart, representing the integer part and the fractional part, respectively.

Both parts have the same sign as x. Analogous to the modf function in C.

Example:

doAssert splitDecimal(5.25) == (intpart: 5.0, floatpart: 0.25)
doAssert splitDecimal(-2.73) == (intpart: -2.0, floatpart: -0.73)
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func sqrt(x: float32): float32 {.importc: "sqrtf", header: "<math.h>",
                                 ...raises: [], tags: [], forbids: [].}
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func sqrt(x: float64): float64 {.importc: "sqrt", header: "<math.h>",
                                 ...raises: [], tags: [], forbids: [].}

Computes the square root of x.

See also:

Example:

doAssert almostEqual(sqrt(4.0), 2.0)
doAssert almostEqual(sqrt(1.44), 1.2)
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func sum[T](x: openArray[T]): T

Computes the sum of the elements in x.

If x is empty, 0 is returned.

See also:

Example:

doAssert sum([1, 2, 3, 4]) == 10
doAssert sum([-4, 3, 5]) == 4
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func tan(x: float32): float32 {.importc: "tanf", header: "<math.h>", ...raises: [],
                                tags: [], forbids: [].}
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func tan(x: float64): float64 {.importc: "tan", header: "<math.h>", ...raises: [],
                                tags: [], forbids: [].}

Computes the tangent of x.

See also:

Example:

doAssert almostEqual(tan(degToRad(45.0)), 1.0)
doAssert almostEqual(tan(PI / 4), 1.0)
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func tanh(x: float32): float32 {.importc: "tanhf", header: "<math.h>",
                                 ...raises: [], tags: [], forbids: [].}
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func tanh(x: float64): float64 {.importc: "tanh", header: "<math.h>",
                                 ...raises: [], tags: [], forbids: [].}

Computes the hyperbolic tangent of x.

See also:

Example:

doAssert almostEqual(tanh(0.0), 0.0)
doAssert almostEqual(tanh(1.0), 0.7615941559557649)
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func trunc(x: float32): float32 {.importc: "truncf", header: "<math.h>",
                                  ...raises: [], tags: [], forbids: [].}
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func trunc(x: float64): float64 {.importc: "trunc", header: "<math.h>",
                                  ...raises: [], tags: [], forbids: [].}

Truncates x to the decimal point.

See also:

Example:

doAssert trunc(PI) == 3.0
doAssert trunc(-1.85) == -1.0
Source   Edit