LOG — Natural logarithm function#
-
LOG(X)#
LOG(X)
computes the natural logarithm ofX
, i.e. the logarithm to the base e.- Parameters
X – The type shall be
REAL
orCOMPLEX
.- Returns
The return value is of type
REAL
orCOMPLEX
. The kind type parameter is the same asX
. IfX
isCOMPLEX
, the imaginary part omega is in the range -pi < omega leq pi.
- Standard:
Fortran 77 and later, has GNU extensions
- Class:
Elemental function
- Syntax:
RESULT = LOG(X)
- 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)
Fortran 77 or later
DLOG(X)
REAL(8) X
REAL(8)
Fortran 77 or later
CLOG(X)
COMPLEX(4) X
COMPLEX(4)
Fortran 77 or later
ZLOG(X)
COMPLEX(8) X
COMPLEX(8)
GNU extension
CDLOG(X)
COMPLEX(8) X
COMPLEX(8)
GNU extension