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/GNU Fortran 7

9.175 LOG — Natural logarithm function

Description:

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

Standard:

Fortran 77 and later

Class:

Elemental function

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

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Licensed under the GNU Free Documentation License, Version 1.3.
https://gcc.gnu.org/onlinedocs/gcc-7.1.0/gfortran/LOG.html