(PHP 4, PHP 5, PHP 7)
log — Natural logarithm
$arg
[, float $base = M_E
] )
If the optional base parameter is specified,
log() returns logbase
arg, otherwise log()
returns the natural logarithm of arg.
argThe value to calculate the logarithm for
baseThe optional logarithmic base to use (defaults to 'e' and so to the natural logarithm).
The logarithm of arg to
base, if given, or the
natural logarithm.