# Math

Execute and test PHP functions with an mathmatic background. These functions use and except only float and integer values.

### abs

Returns the absolute value of \$number.

### acos

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.

### acosh

Returns the inverse hyperbolic cosine of \$arg, i.e. the value whose hyperbolic cosine is \$arg.

### asin

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.

### asinh

Returns the inverse hyperbolic sine of \$arg, i.e. the value whose hyperbolic sine is \$arg.

### atan2

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).

### atan

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.

### atanh

Returns the inverse hyperbolic tangent of \$arg, i.e. the value whose hyperbolic tangent is \$arg.

### base_convert

Returns a string containing \$number represented in base \$tobase. The base in which \$number is given is specified in \$frombase. Both \$frombase and \$tobase have to be between 2 and 36, inclusive. Digits in numbers with a base higher than 10 will be represented with the letters a-z, with a meaning 10, b meaning 11 and z meaning 35.

### bindec

Returns the decimal equivalent of the binary number represented by the \$binaryString argument.

### calculate

This function calculates a mathmatic formula. It is somewhat like a calculator, but without an usable frontend. Often you have the problem, that you just want write down the complete formular, but on GUI-based calculators you can't, here you can! Allowed are the usual operators (+, -, *, /, %) and the following functions:

• exp(\$arg) (exp(1) = 2,718...)
• log(\$arg, \$basis) (log(2, 8) = 1/3)
• pow(\$basis, \$exponent) (pow(4, 2) = 16)
• sqrt(\$arg) (sqrt(16) = 4)

Attention: The comma (,) is reserved to devide the parameters of function. The comma in this way is represented by the dot (.).

### ceil

Returns the next highest integer value by rounding up \$value if necessary.

### cos

cos() returns the cosine of the \$arg parameter. The arg parameter is in radians.

### cosh

Returns the hyperbolic cosine of \$arg, defined as (exp(arg) + exp(-arg))/2.

### decbin

Returns a string containing a binary representation of the given \$number argument. The largest number that can be converted is 4294967295 in decimal resulting to a string of 32 1's.

### dechex

Returns a string containing a hexadecimal representation of the given \$number argument. The largest number that can be converted is 4294967295 in decimal resulting to "ffffffff".

### decoct

Returns a string containing an octal representation of the given \$number argument. The largest number that can be converted is 4294967295 in decimal resulting to "37777777777".

This function converts \$number from degrees to the radian equivalent.

### exp

Returns e raised to the power of \$arg.

### expm1

expm1() returns the equivalent to 'exp(\$arg) - 1' computed in a way that is accurate even if the value of \$arg is near zero, a case where 'exp(\$arg) - 1' would be inaccurate due to subtraction of two numbers that are nearly equal.

### floor

Returns the next lowest integer value by rounding down \$value if necessary.

### fmod

Returns the floating point remainder of dividing the dividend (\$x) by the divisor (\$y). The reminder (r) is defined as: \$x = i * \$y + r, for some integer i. If \$y is non-zero, r has the same sign as \$x and a magnitude less than the magnitude of \$y.

### hexdec

Returns the decimal equivalent of the hexadecimal number represented by the \$hexString argument. hexdec() converts a hexadecimal string to a decimal number.

### hypot

hypot() returns the length of the hypotenuse of a right-angle triangle with sides of length \$x and \$y, or the distance of the point (\$x, \$y) from the origin. This is equivalent to sqrt(\$x*\$x + \$y*\$y).

### is_finite

Checks whether \$val is a legal finite on this platform.

### is_infinite

Returns TRUE if \$val is infinite (positive or negative), like the result of log(0) or any value too big to fit into a float on this platform.

### is_nan

Checks whether \$nval is 'not a number', like the result of acos(1.01).

### log10

Returns the base-10 logarithm of \$arg.

### log1p

log1p() returns log(1 + \$number) computed in a way that is accurate even when the value of \$number is close to zero. log() might only return log(1) in this case due to lack of precision.

### log

If the optional base parameter is specified, log() returns logbase \$arg, otherwise log() returns the natural logarithm of \$arg.

### max

If the first and only parameter is an array, max() returns the highest value in that array. If at least two parameters are provided, max() returns the biggest of these values.

### min

If the first and only parameter is an array, min() returns the lowest value in that array. If at least two parameters are provided, min() returns the smallest of these values.

### mt_rand

Many random number generators of older libcs have dubious or unknown characteristics and are slow. By default, PHP uses the libc random number generator with the rand() function. The mt_rand() function is a drop-in replacement for this. It uses a random number generator with known characteristics using the « Mersenne Twister », which will produce random numbers four times faster than what the average libc rand() provides.

If called without the optional \$min, \$max arguments mt_rand() returns a pseudo-random value between 0 and mt_getrandmax(). If you want a random number between 10 and 100 (inclusive), for example, use mt_rand(10, 100).

### octdec

Returns the decimal equivalent of the octal number represented by the \$octalString argument.

### pow

Returns \$base raised to the power of \$exp.

This function converts \$number from radian to degrees.

### rand

If called without the optional \$min, \$max arguments rand() returns a pseudo-random integer between 0 and getrandmax(). If you want a random number between 5 and 15 (inclusive), for example, use rand(5, 15).

### round

Returns the rounded value of \$val to specified \$precision (number of digits after the decimal point). \$precision can also be negative or zero (default).

### sin

sin() returns the sine of the \$arg parameter. The \$arg parameter is in radians.

### sinh

Returns the hyperbolic sine of \$arg, defined as (exp(\$arg) - exp(-\$arg))/2.

### sqrt

Returns the square root of \$arg.

### tan

tan() returns the tangent of the \$arg parameter. The \$arg parameter is in radians.

### tanh

Returns the hyperbolic tangent of \$arg, defined as sinh(\$arg)/cosh(\$arg).