log(z) -> Float | Complex
log(z, b) -> Float | Complex
z の対数を返します。
例 require "cmath" CMath.log(Complex(0, 0)) # => -Infinity+0.0i CMath.log(0) # => -Infinity
require "cmath" CMath.log(Complex(0, 0)) # => -Infinity+0.0i CMath.log(0) # => -Infinity