Lahey/GNU Fortran

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8.152 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 \leq \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) LF, 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