PHP log1p() Function – Accurate Computation of log(1 + number)

The log1p() function in PHP returns log(1 + number), providing accurate results even when the input number is close to zero, where the standard log() may lose precision.

Signature: float log1p(float $number) Parameter: $number – the number to be processed.

Return value: The natural logarithm of 1 + $number.

Example:

<?php
echo log1p(2.7183)."<br>";
echo log1p(2)."<br>";
echo log1p(1)."<br>";
echo log1p(0);
?>

Output:

1.3132665745863
1.0986122886681
0.69314718055995
0