MAT file save and load in MATLAB

Introduction

Saving data to a MAT file lets you keep your work safe and load it later. It helps you reuse variables without running the whole program again.

You want to save your workspace variables after a long calculation.

You need to share data with a friend or colleague who uses MATLAB.

You want to pause your work and continue later without losing data.

You want to load example data for testing your program.

You want to save results from a simulation to analyze later.

Syntax

MATLAB

save('filename.mat', 'var1', 'var2', ...)
load('filename.mat')

The save command stores variables into a file with .mat extension.

The load command reads variables back into the workspace.

Examples

This saves variables a and b into mydata.mat.

MATLAB

a = 5;
b = [1, 2, 3];
save('mydata.mat', 'a', 'b')

This clears variables and then loads them back from the file.

MATLAB

clear a b
load('mydata.mat')

This saves all workspace variables into allvars.mat.

MATLAB

save('allvars.mat')

This loads the file into a structure data and accesses variable a.

MATLAB

data = load('mydata.mat');
a = data.a;

Sample Program

This program saves variables x and y to a file, clears them from memory, then loads them back and displays their values.

MATLAB

x = 10;
y = [4, 5, 6];
save('example.mat', 'x', 'y')
clear x y
load('example.mat')
disp(x)
disp(y)

Important Notes

If you save without specifying variables, MATLAB saves all workspace variables.

Loading a MAT file restores variables with their original names.

You can also load into a structure to avoid overwriting existing variables.

Summary

Use save to store variables in a MAT file.

Use load to bring variables back into your workspace.

This helps keep your data safe and reuse it anytime.