MATLAB Programming

7 Working with Scientific Data Formats
Common Data Format (CDF) Files
MATLAB includes functions that let you import and export data using the
Common Data Format (CDF). CDF was created by the National Space
Science Data Center (NSSDC) to provide a self-describing data storage
and manipulation format that matches the structure of scientific data and
applications (i.e., statistical and numerical methods, visualization, and
management). The MATLAB CDF functions are described in the following
sections:
• “Getting Information About CDF Files” on page 7-2
• “Importing Data from a CDF File” on page 7-3
• “Exporting Data to a CDF File” on page 7-6
Getting Information About CDF Files
To get information about the contents of a CDF file, use the cdfinfo function.
The cdfinfo function returns a structure containing general information
about the file and detailed information about the variables and attributes in
the file.
ThefollowingexamplereturnsinformationaboutthesampleCDFfile
included with MATLAB. To determine the variables contained in the file, view
the Variables field. This field contains a cell array that lists all the variables
in the file with information that describes the variable, such as name, size, and
data type. For an example, see “Importing Data from a CDF File” on page 7-3.
Note Because cdfinfo creates temporary files, make sure that your current
working directory is writable before attempting to use the function.
info = cdfinfo('example.cdf')
info =
Filename: 'example.cdf'
FileModDate: '09-Mar-2001 16:45:22'
FileSize: 1240
7-2