math(3)

NAME
math - Mathematical functions.

DESCRIPTION

This module provides an interface to a number of mathematical functions.

FUNCTIONS

acos(X) -> float() when X :: number().

    Returns the arc cosine of X in radians.

  Examples

    1> math:acos(1.0).
    0.0
acosh(X) -> float() when X :: number().

    Returns the inverse hyperbolic cosine of X.

  Examples

    1> math:acosh(1.0).
    0.0
asin(X) -> float() when X :: number().

    Returns the arc cosine of X in radians.

  Examples

    1> math:asin(0.0).
    0.0
asinh(X) -> float() when X :: number().

    Returns the inverse hyperbolic sine of X.

  Examples

    1> math:asinh(0.0).
    0.0
atan(X) -> float() when X :: number().

    Returns the arc tangent of X in radians.

  Examples

    1> math:atan(0.0).
    0.0
atan2(Y, X) -> float() when Y :: number(), X :: number().

    Returns the arc tangent of Y/X in radians, using the signs of both arguments to determine the quadrant of the return value.

  Examples

    1> math:atan2(0.0, -10.0).
    3.141592653589793
atanh(X) -> float() when X :: number().

    Returns the inverse hyperbolic tangent of X.

  Examples

    1> math:atanh(0.0).
    0.0
ceil(X) -> float() when X :: number().

    Returns the ceiling of X.

  Examples

    1> math:ceil(7.5).
    8.0
    2> math:ceil(-5.5).
    -5.0
    3> math:ceil(1.0).
    1.0
cos(X) -> float() when X :: number().

    Returns the cosine of X in radians.

  Examples

    1> math:cos(0.0)
    1.0
cosh(X) -> float() when X :: number().

    Returns the hyperbolic cosine of X.

  Examples

    1> math:cosh(0.0)
    1.0
erf(X) -> float() when X :: number().

    Returns the error function of X.

    See Error function (Wikipedia).

  Examples

    1> math:erf(0.0).
    0.0
    2> math:erf(10.0).
    1.0
erfc(X) -> float() when X :: number().

    Returns 1.0 - erf(X), computed using methods that avoid cancellation for large X.

  Examples

    1> math:erfc(0.0).
    1.0
exp(X) -> float() when X :: number().

    Returns e raised to the power of X.

  Examples

    1> math:exp(0).
    1.0
    2> trunc(100 * math:exp(1)).
    271
floor(X) -> float() when X :: number().

    Returns the floor of X.

  Examples

    1> math:floor(9.1).
    9.0
    2> math:floor(-1.5).
    -2.0
    3> math:floor(1.0)
    1.0
fmod(X, Y) -> float() when X :: number(), Y :: number().

    Returns the floating point remainder X divided by Y.

  Examples

    1> math:fmod(10.5, 8.0).
    2.5
log(X) -> float() when X :: number().

    Returns the natural logarithm of X.

  Examples

    1> math:log(1.0).
    0.0
    2> math:log(2.718281828459045).
    1.0
log10(X) -> float() when X :: number().

    Returns logarithm of X to base 10.

  Examples

    1> math:log10(1.0).
    0.0
    2> math:log10(10.0).
    1.0
    3> math:log10(100).
    2.0
log2(X) -> float() when X :: number().

    Returns logarithm of X to base 2.

  Examples

    1> math:log2(1.0).
    0.0
    2> math:log2(2.0).
    1.0
    3> math:log2(64).
    6.0
pi() -> float().

    Returns the ratio of the circumference of a circle to its diameter.

  Examples

    1> math:pi().
    3.141592653589793
pow(X, N) -> float() when X :: number(), N :: number().

    Raise X to the power N.

  Examples

    1> math:pow(2, 6).
    64.0
    2> math:pow(10.0, 3.0).
    1000.0
sin(X) -> float() when X :: number().

    Returns the sine of X in radians.

  Examples

    1> math:sin(0.0)
    0.0
sinh(X) -> float() when X :: number().

    Returns the hyperbolic sine of X.

  Examples

    1> math:sinh(0.0)
    0.0
sqrt(X) -> float() when X :: number().

    Returns the non-negative square root of X.

  Examples

    1> math:sqrt(2).
    1.4142135623730951
    2> math:sqrt(100.0).
    10.0
tan(X) -> float() when X :: number().

    Returns the tangent of X in radians.

  Examples

    1> math:tan(0.0)
    0.0
tanh(X) -> float() when X :: number().

    Returns the hyperbolic tangent of X.

  Examples

    1> math:tan(0.0)
    0.0
tau() -> float().

    Returns the ratio of the circumference of a circle to its radius.

    This constant is equivalent to a full turn when described in radians.

  Examples

    1> math:tau().
    6.283185307179586
    2> math:tau() == 2 * math:pi().
    true