function complexLog (c) {
    return c.log()
  }
Calculate the logarithm of a value.

To avoid confusion with the matrix logarithm, this function does not
apply to matrices.

Syntax:

   math.log(x)
   math.log(x, base)

Examples:

   math.log(3.5)                  // returns 1.252762968495368
   math.exp(math.log(2.4))        // returns 2.4

   math.pow(10, 4)                // returns 10000
   math.log(10000, 10)            // returns 4
   math.log(10000) / math.log(10) // returns 4

   math.log(1024, 2)              // returns 10
   math.pow(2, 10)                // returns 1024

See also:

   exp, log2, log10, log1p

@param {number | BigNumber | Fraction | Complex} x
           Value for which to calculate the logarithm.
@param {number | BigNumber | Fraction | Complex} [base=e]
           Optional base for the logarithm. If not provided, the natural
           logarithm of `x` is calculated.
@return {number | BigNumber | Fraction | Complex}
           Returns the logarithm of `x`