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c
c In this example we will (1) open an HDF file, (2) create the swath
c interface within the file and (3) define the swath field dimensions.
c
program setupswath
integer status, swdefdim, swdefmap, swdefimap
integer swdetach, swclose
integer*4 swfid, swid, swopen, swcreate
integer*4 indx(12) /0,1,3,6,7,8,11,12,14,24,32,39/
integer DFACC_CREATE
parameter (DFACC_CREATE=4)
integer SD_UNLIMITED
parameter (SD_UNLIMITED=0)
c
c We first open the HDF swath file, "SwathFile.hdf". Because this
c file does not already exist, we use the DFACC_CREATE access
c code in the open statement. The SWopen routine returns the swath
c file id, swfid, which is used to identify the file in subsequent
c routines in the library.
c
swfid = swopen("SwathFile_created_with_hadeos_sample_file_write"//
1"r_of_HDFEOS2_version_219_or_higher_release.hdf",DFACC_CREATE)
c
c The first of these, SWcreate, creates the swath, "Swath1", within the
c file designated by the file id, swfid. It returns the swath id, SWid,
c which identifies the swath in subsequent routines. We will show how
c to define, write and read field swaths in later programs.
c
swid = swcreate(swfid, "Swath1")
c
c Typically, many fields within a swath share the same dimension. The
c swath interface therefore provides a way of defining dimensions that
c will then be used to define swath fields. A dimension is defined with
c a name and a size and is connected to the particular swath through the
c swath id. In this example, we define the geo- location track and
c cross track dimensions with size 20 and 10 respectively and two
c dimensions corresponding to these but with twice the resolution.
c We also define a dimension corresponding to a number of spectral
c bands.
status = swdefdim(swid, "GeoTrack", 20)
status = swdefdim(swid, "GeoXtrack", 10)
status = swdefdim(swid, "Res2tr", 40)
status = swdefdim(swid, "Res2xtr", 20)
status = swdefdim(swid, "Bands", 15)
status = swdefdim(swid, "IndxTrack", 12)
c Define Unlimited (appendable) dimension
status = swdefdim(swid, "Unlim", SD_UNLIMITED)
c
c Once the dimensions are defined, the relationship (mapping)between the
c geolocation dimensions, such as track and cross track, and the data
c dimensions, must be established. This is done through the SWdefdimmap
c routine. It takes as input the swath id, the names of the dimensions
c designating the geolocation and data dimensions, respectively, and the
c offset and increment defining the relation.
c
c In the first example we relate the "GeoTrack" and "Res2tr" dimensions
c with an offset of 0 and an increment of 2. Thus the ith element of
c "Geotrack" corresponds to the 2 * ith element of "Res2tr".
c
c In the second example, the ith element of "GeoXtrack" corresponds to the
c 2 * ith + 1 element of "Res2xtr".
c
status = swdefmap(swid, "GeoTrack", "Res2tr", 0, 2)
status = swdefmap(swid, "GeoXtrack", "Res2xt", 1, 2)
status = swdefimap(swid, "IndxTrack", "Res2tr", indx)
c
c We now close the swath interface with the SWdetach routine. This step
c is necessary to properly store the swath information within the file.
c
status = swdetach(swid)
c
c Finally, we close the swath file using the SWclose routine. This will
c release the swath file handles established by SWopen.
c
status = swclose(swfid)
stop
end
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