expm1

Returns exp(number) - 1, computed in a way that is accurate even when the value of number is close to zero (PHP 4 >= 4.0.7, PHP 5)
float expm1 ( float arg )

Code Examples / Notes » expm1

hagen

Compare this to log1p (which is its inverse). Also, You may have to use a similar workaraound in case the underlying C library does not support expm1: function expm1($x) { return ($x>-1.0e-6 && $x<1.0e-6) ? ($x + $x*$x/2) : (exp($x)-1); }

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expm1

Returns exp(number) - 1, computed in a way that is accurate even when the value of number is close to zero (PHP 4 >= 4.0.7, PHP 5) float expm1 ( float arg )

Code Examples / Notes » expm1

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Returns exp(number) - 1, computed in a way that is accurate even when the value of number is close to zero (PHP 4 >= 4.0.7, PHP 5)
float expm1 ( float arg )