expm1

(PHP 4 >= 4.1.0, PHP 5, PHP 7)

expm1 — Returns exp(number) - 1, computed in a way that is accurate even when the value of number is close to zero

Description

expm1 ( float $arg ) : float

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.

Parameters

arg

The argument to process

Return Values

'e' to the power of arg minus one

See Also

  • log1p() - Returns log(1 + number), computed in a way that is accurate even when the value of number is close to zero
  • exp() - Calculates the exponent of e

© 1997–2020 The PHP Documentation Group
Licensed under the Creative Commons Attribution License v3.0 or later.
https://www.php.net/manual/en/function.expm1.php