(PHP 4 >= 4.1.0, PHP 5)
expm1 -- Returns exp(number) - 1, computed in a way that is accurate even when the value of number is close to zero| Warning |
This function is EXPERIMENTAL. The behaviour of this function, the name of this function, and anything else documented about this function may change without notice in a future release of PHP. Use this function at your own risk. |
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.
Note: This function is not implemented on Windows platforms.