MATLAB Programming

7 Working with Scientific Data Formats
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2 To read all of the data in the CDF file, use the cdfread function. The
function returns the data in a 24-by-5 cell array. The five columns of data
correspond to the five variables; the 24 rows correspond to the 24 records
associated with the Time variable and padding elements for the rows
associated with the other variables. The padding value used is specified
in the CDF file.
data = cdfread('example.cdf');
whos data
Name Size Bytes Class Attributes
data 24x5 14784 cell
3 To read the data associated with a particular variable, use the 'Variable'
parameter, specifying a cell array of variable names as the value of this
parameter. Variable names are case sensitive. For example, the following
code reads the Longitude and Latitude variables from the file. The return
value data is a 24-by-2 cell array, where each cell contains int8 data.
var_time = cdfread('example.cdf','Variable',{'Longitude','Latitude'});
whos var_time
Name Size Bytes Class Attributes
var_time 24x1 4608 cell
Speeding Up Read Operations
The cdfread function offers two ways to speed up read operations when
working with large data sets:
• Reducing the number of elements in the returned cell array
• Returning CDF epoch values as MATLAB serial date numbers rather than
as MATLAB cdfepoch objects
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