Function:     FBLANK

Purpose:      Logical function returning whether argument is a universal
              BLANK (undefined).

Category:     DATA

File:         floating.c

Author:       K.G. Begeman

Use:          LOGICAL FBLANK( DATA )     Input   REAL

              DATA        Data value to check upon.

Notes:        - Each application routine which reads in data must check
                before doing its operation whether a datum has the
                blank value.
              - It is faster to do a direct compare in your application
                routine. The universal BLANK can be obtained with
                subroutine SETFBLANK.

Example:      REAL  BLANK
              CALL SETFBLANK( BLANK )
              FOR I = 1, N
                 IF (BLANK .EQ. DATA(I))
                 THEN
                    CALL SETFBLANK(RESULT(I))
                 ELSE
                    RESULT(I) = 2.0 * DATA(I) + 3.1456
                 CIF
              CFOR

Warning:      This routine is system dependent!

Updates:      Oct 24, 1988: KGB, Document created.
              Apr 23, 1991: KGB, Implemented for HP 9000.
              May 16, 1991: KGB, Incorporated in floating.c.