dsp.MatFileReader

Read MAT file

Description

The dsp.MatFileReader System object™ reads V7.3 MAT files.

To read V7.3 MAT files:

  1. Create the dsp.MatFileReader object and set its properties.

  2. Call the object with arguments, as if it were a function.

To learn more about how System objects work, see What Are System Objects? (MATLAB).

Creation

Syntax

mfr = dsp.MatFileReader
mfr = dsp.MatFileReader(fname,vname,framesize)
mfr = dsp.MatFileReader(___,Name,Value)

Description

mfr = dsp.MatFileReader returns a System object, mfr, to read a stream of scalar data from a V7.3 MAT file.

mfr = dsp.MatFileReader(fname,vname,framesize) reads frames of MAT file data, using the specified file name, variable name, and frame size.

example

mfr = dsp.MatFileReader(___,Name,Value) reads MAT file data with each specified property set to the specified value.

Properties

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Unless otherwise indicated, properties are nontunable, which means you cannot change their values after calling the object. Objects lock when you call them, and the release function unlocks them.

If a property is tunable, you can change its value at any time.

For more information on changing property values, see System Design in MATLAB Using System Objects (MATLAB).

Name of the MAT file from which to read, specified as a character vector or a string scalar. Specify the full path for the file only if the file is not on the MATLAB® path.

Name of the variable to read from the MAT file, specified as a character vector or a string scalar.

Number of samples per output frame to read from the MAT file on each call to the object algorithm, specified as a positive, integer-valued scalar.

Usage

For versions earlier than R2016b, use the step function to run the System object algorithm. The arguments to step are the object you created, followed by the arguments shown in this section.

For example, y = step(obj,x) and y = obj(x) perform equivalent operations.

Syntax

data = mfr()

Description

example

data = mfr() reads data from a specified variable stored in a MAT-file. The variable is assumed to be N-dimensional and a MATLAB built-in data type. The data is read into MATLAB by reading along the first dimension.

Output Arguments

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Data read from the MAT file, returned as a scalar, vector, or a matrix. The data can be an N-dimensional array.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

Object Functions

To use an object function, specify the System object as the first input argument. For example, to release system resources of a System object named obj, use this syntax:

release(obj)

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isDoneEnd-of-data status
stepRun System object algorithm
releaseRelease resources and allow changes to System object property values and input characteristics
resetReset internal states of System object

Examples

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Note: This example runs only in R2016b or later. If you are using an earlier release, replace each call to the function with the equivalent step syntax. For example, myObject(x) becomes step(myObject,x).

Read a MAT file using the MatFileReader object.

filename = [tempname '.mat'];  % Create variable name
originalData = rand(40,2);
save(filename,'originalData','-v7.3'); % Write to MAT file
 
mfr = dsp.MatFileReader(filename,'VariableName',...
   'originalData','SamplesPerFrame', 4);  
while ~isDone(mfr)         % Stream data into MATLAB
    finalData = mfr();
end

Introduced in R2012b