Create and Edit Variables - MATLAB & Simulink (original) (raw)

Create Variables

The MATLAB® workspace consists of the variables you create and store in memory during a MATLAB session. You can create new variables in the workspace by running MATLAB code or using existing variables.

To create a new variable, enter the variable name in the Command Window, followed by an equal sign (=) and the value you want to assign to the variable. For example, if you run these statements, MATLAB adds four variables to the workspace.

x = 5.71; A = [1 2 3; 4 5 6; 7 8 9]; I = besseli(x,A); C = {A A A};

You do not have to declare variables before assigning values to them.

If you do not end the assignment statement with a semicolon (;), MATLAB displays the result in the Command Window. The Workspace panel displays the result of assigning a scalar value to a variable.

If you do not explicitly assign the output of a statement to a variable, MATLAB generally assigns the result to the reserved wordans. The value of ans changes with every statement that returns an output value that is not assigned to a variable. For example, call a function and do not assign the output to a variable.

View Workspace Contents

To view a list of variables in your base workspace, use the Workspace panel. For example, open the Workspace panel using the workspace function and display the name, value, size, and class of variables in your workspace.

Workspace panel showing the name, value, size, and class of four variables

You also can use the who command in the Command Window to view a list of variables. To list information about size and class, use thewhos command. For example, use thewho and whos commands to view your workspace contents.

Your variables are:

A C I x

Name Size Bytes Class Attributes

A 3x3 72 double C 1x3 576 cell I 3x3 72 double x 1x1 8 double

View Variable Contents

You can view the contents of a variable by entering the variable name at the command prompt. For example, view the contents of a scalar variable.

You can also view the contents of a variable in the Variables editor. For example, open a matrix in the Variables editor using the openvar function and view the contents of the matrix.

Variables editor showing a 2-by-2 matrix of type double with values [1 3; 2 4]

Edit Variable Contents

You can edit the contents of scalar and small vector or matrix variables in the Workspace panel. Click the variable value to select it, and then enter a new value to overwrite the existing value. You can also press Enter to edit the existing value. For example, change the value of an element in a small matrix using the Workspace panel.

Workspace panel with an edit field in the Value column for the variable A

To edit the contents of other kinds of variables, use the Variables editor. For example, change the value of an element in a table variable using the Variables editor.

Variables editor with edit an field for the first element in the first variable

You can also navigate, resize, or visualize data and generate code using the Variables editor. For information about other editing actions, see Variables editor.

See Also

Variables Editor | Workspace Panel

Topics