LOG (number)

  Class:  Elemental function - Generic

  Returns the natural log (base e) of a real or complex argument.

  If the argument is real, its value must be greater than zero.  If
  the argument is complex, its value must not be (0.,0.).
  +------+---------+----------+------------+-------------+
  | 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  |
  |      |         | CQLOG    | COMPLEX*32 | COMPLEX*32  |
  +------+---------+----------+------------+-------------+

  Note: The setting of compiler options specifying real
        size can affect ALOG and CLOG.