Loading...
Searching...
No Matches

## dlaisnan()

logical function dlaisnan | ( | double precision, intent(in) | din1,
|  | double precision, intent(in) | din2 )

DLAISNAN tests input for NaN by comparing two arguments for inequality.

Download DLAISNAN + dependencies [TGZ] [ZIP] [TXT]

Purpose:

      !>
      !> This routine is not for general use.  It exists solely to avoid
      !> over-optimization in DISNAN.
      !>
      !> DLAISNAN checks for NaNs by comparing its two arguments for
      !> inequality.  NaN is the only floating-point value where NaN != NaN
      !> returns .TRUE.  To check for NaNs, pass the same variable as both
      !> arguments.
      !>
      !> A compiler must assume that the two arguments are
      !> not the same variable, and the test will not be optimized away.
      !> Interprocedural or whole-program optimization may delete this
      !> test.  The ISNAN functions will be replaced by the correct
      !> Fortran 03 intrinsic once the intrinsic is widely available.
      !>

Parameters

  [in]

  DIN1

      !>          DIN1 is DOUBLE PRECISION
      !>

  [in]

  DIN2

      !>          DIN2 is DOUBLE PRECISION
      !>          Two numbers to compare for inequality.
      !>

Author
  Univ. of Tennessee
  Univ. of California Berkeley
  Univ. of Colorado Denver
  NAG Ltd.