alter_sds_values.f

      program  alter_data

      implicit none

C

C     Parameter declaration.

C

      character*7  FILE_NAME

      integer      DFACC_WRITE

      parameter   (FILE_NAME = 'SDS.hdf',

     +             DFACC_WRITE = 2)

C

C     Function declaration.

C

      integer sfstart, sfselect, sfwdata, sfendacc, sfend

C

C**** Variable declaration *******************************************

C

      integer sd_id, sds_id, sds_index

      integer start(2), edges(2), stride(2)

      integer status

      integer new_data(2) 

C

C**** End of variable declaration ************************************

C

C

C     Open the file and initialize the SD interface.

C

      sd_id = sfstart(FILE_NAME, DFACC_WRITE)

C

C     Select the first data set.

C     

      sds_index = 0

      sds_id = sfselect(sd_id, sds_index)

C

C     Initialize the start, edge, and stride parameters to write 

C     two elements into 2nd row, 10th column and 11th column places.

C     

C     Specify 2nd row.

C

      start(1) = 1 

C

C     Specify 10th column.

C

      start(2) = 9 

      edges(1) = 1 

C

C     Two elements are written along 2nd row.

C

      edges(2) = 2 

      stride(1) = 1

      stride(2) = 1

C

C     Initialize the new values to be written.

C

      new_data(1) = 1000

      new_data(2) = 1000

C

C     Write the new values. 

C

      status = sfwdata(sds_id, start, stride, edges, new_data)

C

C     Terminate access to the data set.

C

      status = sfendacc(sds_id)

C

C     Terminate access to the SD interface and close the file.

C

      status = sfend(sd_id)

      end