logBase

log to the base of

>>> logBase 2 8
2.9999999999999996

Takes the logarithm of the second argument in the base of the first.

>>> logBase _2 _8
3.0

Natural logarithm differentiable function.

Examples of usage

>>> import Prelude (Float)

>>> import InfBackprop (call, derivative)

>>> call logBase (2, 8) :: Float
3.0

>>> import Debug.SimpleExpr.Expr (variable)

>>> x = variable "x"

>>> n = variable "n"

>>> derivative logBase (n, x)
((1·(-(log(x))·(1/(log(n)·log(n)))))·(1/n),(1·(1/log(n)))·(1/x))

Apply logarithm to each element of the array where the base is in the same cell in the second array.

logBaseA arr1 arr2 == zipWith logBase arr1 arr2

• Partial Throws an error when arrays do not have matching sizes

Exact integer logarithm of a natural number NB: Only works when the argument is a power of the base

Op for logBase

Safe logBase with default values returned on exception.

>>> logBaseOr "d" "base" "val" :: SymAlgReal
(ite (= base 1.0) d (fdiv (log val) (log base)))

Safe logBase with 0 returned on exception.

Safe logBase with default values returned on exception.