VMS Help FORTRAN, Intrinsic Procedures, LOG  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  LOG (number)

  A function that returns the natural log (base e) of the argument.
  +------+---------+----------+------------+-------------+
  | Args | Generic | Specific |  Argument  | Result Type |
  +------+---------+----------+------------+-------------+
  |  1   |  LOG    | ALOG     | REAL*4     | REAL*4      |
  |      |         | DLOG     | REAL*8     | REAL*8      |
  |      |         | QLOG     | REAL*16    | REAL*16     |
  |      |         | CLOG     | COMPLEX*8  | COMPLEX*8   |
  |      |         | CDLOG    | COMPLEX*16 | COMPLEX*16  |
  |      |         | ZLOG     | COMPLEX*16 | COMPLEX*16  |
  +------+---------+----------+------------+-------------+
  The argument for ALOG and DLOG must be greater than zero.  The
  argument for CLOG and CDLOG must not be (0.,0.).