MATLAB Programming

Hierarchical Data Format (HDF4) Files
• Name of the SD API routine, endaccess in this case
• HDF4 SD data set identifier (sds_id) returnedbySDselect
Forexample,thiscodeclosesthedataset:
stat = hdfsd('endaccess',sds_id);
You must close access to all the data sets in an HDF4 file before closing it.
Step 8: Closing the HDF4 File. After writing data to a data set and closing
the data set, you must also close the HDF4 file. In the HDF4 SD API, you
use the SDend routine. In MATLAB, use the hdfsd function, specifying as
arguments:
• Name of the SD API routine, end in this case
• HDF4 SD file identifier (sd_id) returnedbySDstart
Forexample,thiscodeclosesthedataset:
stat = hdfsd('end',sd_id);
Example: Exporting Data Using the HDF4 SD API Functions
The following sections provide a step-by-step example of how to export data
from the MATLAB workspace to an HDF4 file using Scientific Data (SD)
API functions.
• “Step 1: Creating an HDF4 File” on page 7-64
• “Step 2: Creating an HDF4 Data Set” on page 7-64
• “Step 3: Writing MATLAB Data to an HDF4 File” on page 7-66
• “Step 4: Writing Metadata to an HDF4 File” on page 7-68
• “Step 5: Closing HDF4 Data Sets” on page 7-69
• “Step 6: Closing an HDF4 File” on page 7-70
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