LOG — Natural logarithm function

Description

LOG(X) computes the natural logarithm of X, i.e. the logarithm to the base e.

Syntax

RESULT = LOG(X)

Arguments

X The type shall be REAL or COMPLEX.

Return value

The return value is of type REAL or COMPLEX. The kind type parameter is the same as X. If X is COMPLEX, the imaginary part \omega is in the range -\pi < \omega \leq \pi.

Example


program test_log
  real(8) :: x = 2.7182818284590451_8
  complex :: z = (1.0, 2.0)
  x = log(x) ! will yield (approximately) 1
  z = log(z)
end program test_log

Specific names

Name Argument Return type Standard
ALOG(X) REAL(4) X REAL(4) f95, gnu
DLOG(X) REAL(8) X REAL(8) f95, gnu
CLOG(X) COMPLEX(4) X COMPLEX(4) f95, gnu
ZLOG(X) COMPLEX(8) X COMPLEX(8) f95, gnu
CDLOG(X) COMPLEX(8) X COMPLEX(8) f95, gnu

Standard

Fortran 77 and later

Class

Elemental function