cdflib.getVarData

Single value from record in variable

Syntax

datum = cdflib.getVarData(cdfId,varNum,recNum,indices) datum = cdflib.getVarData(cdfId,varNum,recNum)

datum = cdflib.getVarData(cdfId,varNum,recNum,indices) returns a single value from a variable in a Common Data Format (CDF) file.

datum = cdflib.getVarData(cdfId,varNum,recNum) returns a single value from a variable with no dimensions in a Common Data Format (CDF) file.

`cdfId`	Identifier of a CDF file, returned by a call to `cdflib.create` or `cdflib.open`.
`varNum`	Numeric value identifying the variable containing the datum. Variable numbers are zero-based.
`recNum`	Numeric value identifying the location of the datum in the variable. In CDF terminology, this is called the record number. Record numbers are zero-based.
`indices`	Array of dimension indices within the record. Dimension indices are zero-based. If the variable has no dimensions, you can omit this parameter.

datum

Value of the specified record.

Open the example CDF file and retrieve data associated with a variable:

cdfId = cdflib.open("example.cdf");

% Determine how many variables are in the file
info = cdflib.inquire(cdfId);
numVars = info.numVars

numVars =

     6

% Determine if the first variable has dimensions
varnum = 0;
varinfo = cdflib.inquireVar(cdfId,varnum);
vardims = varinfo.dims

vardims =

     []

% Get first data record from variable, without specifying dimensions
recnum = 0;
datum = cdflib.getVarData(cdfId,varnum,recnum)

datum =

   6.3146e+13

% Get dimensions of another variable in file
varnum = 3;
varinfo = cdflib.inquireVar(cdfId,varnum);
vardims = varinfo.dims

vardims =

     4     2     2

% Retrieve the first datum in the record (indices are zero-based)
datum = cdflib.getVarData(cdfId,varnum,recnum,[0 0 0])

datum =

    30

% Clean up
cdflib.close(cdfId)
clear cdfId

This function corresponds to the CDF library C API routine CDFgetzVarData.
To use this function, you must be familiar with the CDF C interface. You can access the CDF documentation at the CDF website.

You can read CDF_INT8 and CDF_TIME_TT2000 variables.