Logarithmic mean of two numbers

Calculates the logarithmic mean of two numbers.

Usage

logmean(a, b, base = exp(1))

Arguments

a

the first operand (must be non-negative)

b

the second operand (must be non-negative)

base

the base of the logarithm used in this calculation. (Default is exp(1).)

Value

0 if a = 0 or b = 0; x1 if a == b; and (a - b) / log(a/b, base = base)

for all other values of a and b

Details

This is an internal helper function for logarithmicmean_byname.

Examples

matsbyname:::logmean(0, 0) # 0
#> [1] 0
matsbyname:::logmean(0, 1) # 0
#> [1] 0
matsbyname:::logmean(1, 0) # 0
#> [1] 0
matsbyname:::logmean(1, 1) # 1
#> [1] 1
matsbyname:::logmean(2, 1)
#> [1] 1.442695
matsbyname:::logmean(1, 2) # commutative
#> [1] 1.442695
matsbyname:::logmean(1, 10) # base = exp(1), the default
#> [1] 3.90865
matsbyname:::logmean(1, 10, base = 10)
#> [1] 9