MATLAB Function Reference

cdfread

Read data from a CDF file

Syntax

• data = cdfread(file)
  data = cdfread(file, 'records', recnums, ...)
  data = cdfread(file, 'variables', varnames, ...)
  data = cdfread(file, 'slices', dimensionvalues, ...)
  [data, info] = cdfread(file, ...)
  

Description

data = cdfread(file) reads all of the variables from each record of the Common Data Format (CDF) file specified in the string, file. The return value, data, is a cell array in which each row contains a record and each column represents a variable.

data = cdfread(file, 'records', recnums, ...) reads only those records specified in the vector, recnums. The record numbers are zero-based. The return value, data, is a cell array having length(recnums) number of rows and as many columns as there are variables.

data = cdfread(file, 'variables', varnames, ...) reads only those variables specified in the 1-by-N or N-by-1 cell array of strings, varnames. The return alue, data, is returned in a cell array having length(varnames) number of columns and a row for each record requested.

data = cdfread(file, 'slices', dimensionvalues, ...) reads specific values from the records of one variable in the CDF file. The N-by-3 matrix, dimensionvalues, indicates which records are to be read by specifying start, interval, and count parameters for each of the N dimensions of the variable. The start parameter is zero-based.

The number of rows in dimensionvalues must be less than or equal to the number of dimensions of the variable. Unspecified rows default to [0 1 N], where N is the total number of values in a record. This causes cdfread to read every value from those dimensions.

Because you can read just one variable at a time, you must also include a 'variables' parameter with this syntax.

[data, info] = cdfread(file, ...) also returns details about the CDF file in the info structure.

Examples

Read all of the data from the file.

• data = cdfread('example.cdf');
  

Read just the data from variable 'Time'.

• data = cdfread('example.cdf', 'Variable', {'Time'});
  

Read the first value in the first dimension, the second value in the second dimension, the first and third values in the third dimension, and all values in the remaining dimension of the variable 'multidimensional'.

• data = cdfread('example.cdf', 'Variable', ... 
  {'multidimensional'}, 'Slices', [0 1 1; 1 1 1; 0 2 2]);
  

This is similar to reading the whole variable into 'data', and then using the MATLAB command

• data{1}(1, 2, [1 3], :)
  

See Also

cdfinfo, cdfwrite, cdfepoch

cdfinfo

cdfwrite