Subroutine:   MINMAX2

Purpose:      Finds the minimum and maximum value in a data
              array of reals, counting the BLANK values.

File:         minmax.c

Author:       K.G. Begeman

Use:          CALL MINMAX2( DATA   ,  Input      REAL ARRAY
                            NDAT   ,  Input      INTEGER
                            AMIN   ,  Output     REAL
                            AMAX   ,  Output     REAL
                            NBLANK )  Output     INTEGER

              DATA          Data array to operate on.
              NDAT          Number of data points in DATA array.
              AMIN          Minimum value in DATA array.
              AMAX          Maximum value in DATA array.
              NBLANK        Number of blanks in DATA array.

Note:         If all values in the data array have the BLANK value,
              the minimum and maximum will also be set to BLANK.

Updates:      Jul 22, 1989: KGB, Document created.
              AUg  8, 1990: KGB, Bug in loop counter fixed