log() [2/2]

static double xtd::math::log ( double  a, double  new_base  )

static

Returns the logarithm of a specified number in a specified base.

Parameters

a	The number whose logarithm is to be found.
new_base	The base of the logarithm.

Returns

One of the values in the following table. (+Infinity denotes math::positive_infinity, -Infinity denotes math::negative_infinity, and math::NaN denotes math::NaN.)

a	new_base	Return value
a > 0	(0 < new_base < 1) -or- (new_base > 1)	log new_base (a)
a < 0	(any value)	xtd::math::NaN
(any value)	new_base < 0	xtd::math::NaN
a != 1	new_base = 0	xtd::math::NaN
a != 1	new_base = xtd::math::positive_infinity	xtd::math::NaN
a = xtd::math::NaN	(any value)	xtd::math::NaN
(any value)	new_base = xtd::math::NaN	xtd::math::NaN
(any value)	new_base = 1	xtd::math::NaN
a = 0	0 < new_base < 1	xtd::math::positive_infinity
a = 0	new_base > 1	xtd::math::negative_infinity
a = xtd::math::positive_infinity	0 < new_base < 1	xtd::math::negative_infinity
a = xtd::math::positive_infinity	new_base > 1	xtd::math::positive_infinity
a = 1	new_base = 0	0
a = 1	new_base = xtd::math::positive_infinity	0