dsp.MatFileWriter

R2026b

Write MAT file

Description

The dsp.MatFileWriter System object™ writes data to a V7.3 MAT file.

To write data to a V7.3 MAT file:

1. Create the dsp.MatFileWriter 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?

Creation

Syntax

mfw = dsp.MatFileWriter

mfw = dsp.MatFileWriter(fname,vname)

mfw = dsp.MatFileWriter(PropertyName=Value)

Description

mfw = dsp.MatFileWriter returns a MAT file writer System object, mfw, that writes data to a V7.3 MAT file.

mfw = dsp.MatFileWriter(fname,vname) returns a MAT file writer System object with the Filename property set to fname and the VariableName property set to vname.

mfw = dsp.MatFileWriter(PropertyName=Value) returns a MAT file writer System object with each specified property set to the specified value. Unspecified properties have default values. For example, to specify the variable name to write to "y", set VariableName to "y".

Properties

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.

Filename — Name of MAT file to write

"Untitled.mat" (default) | character vector | string scalar

Specify the name of a MAT file 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.

VariableName — Name of variable to write

"x" (default) | character vector | string scalar

Name of the variable to which to write, returned as a character vector or a string scalar. This variable is stored in the MAT file. You cannot overwrite a variable that is already in an existing MAT file.

Usage

Syntax

mfw(data)

Description

mfw(data) writes one frame of data to the variable stored in the MAT file. The variable is assumed to be N-dimensional and a MATLAB built-in data type. The data is written to the file by concatenating along the first dimension.

Input Arguments

data — Data to be written to MAT file

scalar | vector | matrix

Data to be written to the MAT file, specified 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)

Common to All System Objects

step	Run System object algorithm
release	Release resources and allow changes to System object property values and input characteristics
reset	Reset internal states of System object

Examples

Write Data Into a MAT File

First, create a variable name.

filename = [tempname '.mat'];

Next, write that variable to a MAT-file.

mfw = dsp.MatFileWriter(filename,VariableName="originalData");
for i = 1:10
    originalData = rand(4,2);
    mfw(originalData);
end
release(mfw); % This will close the MAT file

Finally, load the variable back into MATLAB.

data = load(filename,"originalData");

Plot the data.

plot(data.originalData);

Version History

Introduced in R2012b