(PHP 4 >= 4.1.0, PHP 5, PHP 7) Inverse hyperbolic tangent float atanh ( float $arg ) Returns the inverse hyperbolic tangent of arg, i.e. the value whose hyperbolic tangent is arg. Parameters: arg The argument to process Returns: Inverse hyperbolic tangent of arg Changelog: 5.3.0 This fun

(PHP 4, PHP 5, PHP 7) Arc tangent float atan ( float $arg ) Returns the arc tangent of arg in radians. atan() is the complementary function of tan(), which means that a==tan(atan(a)) for every value of a that is within atan()'s range. Parameters: arg The argument to process Returns: The arc tangent of arg in radians.

(PHP 4, PHP 5, PHP 7) Arc tangent of two variables float atan2 ( float $y, float $x ) This function calculates the arc tangent of the two variables x and y. It is similar to calculating the arc tangent of y / x, except that the signs of both arguments are used to determine the quadrant of the result. The function returns the result in radians, which is between -PI and PI (inclusive). Parameters:

(PHP 4 >= 4.1.0, PHP 5, PHP 7) Inverse hyperbolic sine float asinh ( float $arg ) Returns the inverse hyperbolic sine of arg, i.e. the value whose hyperbolic sine is arg. Parameters: arg The argument to process Returns: The inverse hyperbolic sine of arg Changelog: 5.3.0 This function is

(PHP 4, PHP 5, PHP 7) Arc sine float asin ( float $arg ) Returns the arc sine of arg in radians. asin() is the complementary function of sin(), which means that a==sin(asin(a)) for every value of a that is within asin()'s range. Parameters: arg The argument to process Returns: The arc sine of arg in radians

(PHP 4 >= 4.1.0, PHP 5, PHP 7) Inverse hyperbolic cosine float acosh ( float $arg ) Returns the inverse hyperbolic cosine of arg, i.e. the value whose hyperbolic cosine is arg. Parameters: arg The value to process Returns: The inverse hyperbolic cosine of arg Changelog: 5.3.0 This functi

(PHP 4, PHP 5, PHP 7) Arc cosine float acos ( float $arg ) Returns the arc cosine of arg in radians. acos() is the complementary function of cos(), which means that a==cos(acos(a)) for every value of a that is within acos()' range. Parameters: arg The argument to process Returns: The arc cosine of arg in radians.

(PHP 4, PHP 5, PHP 7) Absolute value number abs ( mixed $number ) Returns the absolute value of number. Parameters: number The numeric value to process Returns: The absolute value of number. If the argument number is of type float, the return type is also float, otherwise it is integer (as float usually has a bigger value range than integer).

(PECL lapack >= 0.1.0) Solve a system of linear equations public static array Lapack::solveLinearEquation ( array $a, array $b ) This function computes the solution to the system of linear equations with a square matrix A and multiple right-hand sides B. Solves A * X = B for multiple B. Parameters: a Square matrix of linear equations b

(PECL lapack >= 0.1.0) Calculated the singular values of a matrix public static array Lapack::singularValues ( array $a ) Calculate the singular values of the matrix A. Parameters: a The matrix to calculate the singular values for Returns: The singular values Examples: Using Lapack