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Specify reserve percentage for variable




cdflib.setVarReservePercent(cdfId,varNum,percent) specifies the compression reserve percentage for a variable in a Common Data Format (CDF) file.

Input Arguments


Identifier of a CDF file, returned by a call to cdflib.create or


Numeric value identifying a variable in the file. Variable identifiers (variable numbers) are zero-based.


Numeric value specifying the amount of extra space to allocate for a compressed variable, expressed as a percentage. You can specify values between0 (no extra space is reserved) and 100, or values greater than 100. The value specifies the percentage of the uncompressed size of the variable. If you specify a fractional reserve percentages, the library rounds the value down.


Create a CDF, create a variable, set the compression of the variable, and then set the reserve percent for the variable. To run this example, you must be in a writable folder.

cdfId = cdflib.create("your_file.cdf");

% Create a variable in the file
varNum = cdflib.createVar(cdfId,"Time","cdf_int1",1,[],true,[]);
% Set the compression of the variable
% Set the compression reserver percentage

%Clean up
clear cdfId

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reserve percentage

Specifies how much extra space to allocate for a compressed variable. This extra space allows the variable to expand when you write additional records to the variable. If you do not specify this room for growth, the library has to move the variable to the end of the file when the size expands and the space at the original location of the variable becomes wasted space.


This function corresponds to the CDF library C API routine CDFsetzVarReservePercent.

To use this function, you must be familiar with the CDF C interface. You can access the CDF documentation at the CDF website.