expm1
(PHP 4 >= 4.0.7, PHP 5)
expm1 — Returns exp(number) - 1, computed in a way that is accurate even when the value of number is close to zero
Description
float expm1
( float $arg
)
Warning
這個函數是實驗性質的。這個函數的行為、名稱、和關於此函數的任何其他文件在未來PHP的發行中可能會在不通知的情況下改變。 使用此延伸需自行承擔風險。
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: 此函數不適用於 Windows 平台。
Parameters
- arg
-
The argument to process
Return Values
'e' to the power of arg minus one