matlab log

log: Natural logarithm
Syntax: Y = log(X)
Description:
The log function operates element-wise on arrays. Its domain includes
complex and negative numbers, which may lead to unexpected results if
used unintentionally.
Y = log(X) returns the natural logarithm of the elements of X. For
complex or negative , where , the complex logarithm is returned.
log(z) = log(abs(z)) + i*atan2(y,x)
Examples
The statement abs(log(-1)) is a clever way to generate .
ans =
3.1416