logBase -package:clash-prelude

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

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.

Calculate the integer logarithm for an arbitrary base. The base must be greater than 1, the second argument, the number whose logarithm is sought, shall be positive, otherwise the result is meaningless. The following property holds

base ^ integerLogBase# base m <= m < base ^(integerLogBase# base m + 1)

for base > 1 and m > 0. Note: Internally uses integerLog2# for base 2