Main Content

Add Interactive Controls to a Live Script

You can add sliders, drop-downs, check boxes, edit fields, and buttons to your live scripts to control variable values interactively. Adding interactive controls to a script is useful when you want to share the script with others. Use interactive controls to set and change the values of variables in your live script using familiar user interface components.

Insert Controls

To insert a control into a live script, go to the Live Editor tab, and in the Code section, click Control. Then, select from the available options. To replace an existing value with a control, select the value and then insert the control. The Control menu only shows options available for the selected value.

The table below shows the list of available controls:

ControlDescriptionConfiguration Details

Numeric Slider

Use numeric sliders to interactively change the value of a variable by moving the slider thumb to the desired numeric value.

The value to the left of the slider is its current value.

In the Values section, specify a Min, Max, and Step value or select a workspace variable from the drop-down list.

For more information about specifying the slider values using variables, see Link Variables to Controls.

Drop-Down List

Use drop-down lists to interactively change the value of a variable by selecting from a list of values.

Hover over the text displayed in the drop-down list to see its current value.

In the Items > Item Labels field, specify the text that you want to display for each item in the drop-down list.

In the Items > Item Values field, specify the values for each item in the drop-down line. Make sure to enclose text values in quotes or double quotes, because the Live Editor interprets each item in the list as code.

You also can populate the items in the drop-down list using values stores in a variable. For more information, see Link Variables to Controls.

Check Box

Use check boxes to interactively set the value of a variable to either the logical value 1 (true) or the logical value 0 (false).

The displayed state of the check box (checked or not checked) determines its current value.

N/A

Edit Field

Use edit fields to interactively set the value of a variable to any typed input.

The text displayed in the edit field and the selected data type determines its current value.

In the Type section, in the Data type field, select from the available options to specify the data type of the text in the edit field.

Button

Use button controls to interactively run code on button click.

When using button controls, consider setting the Run field for all other controls in the live script to None. Then, the code only runs when the user clicks the button control. This can be useful when the live script requires multiple control values to be set before running the code.

To change the label displayed on the button, in the Label section, enter a label name.

Modify Control Labels

You can hide the code in a live script and only display labeled controls, output, and formatted text. Hiding the code is useful when sharing and exporting live scripts. To hide the code, click the hide code button to the right of the live script. You also can go to the View tab, and in the View section, click Hide Code. To show the code again, click the output inline button or the output on right button.

When the code is hidden, labels display next to the control. To modify the label for a control, right-click the control and select Configure Control. Then, in the Label section, enter a label name. This is also the text that displays on button controls in all views. Press Tab or Enter, or click outside of the control configuration menu to return to the live script.

Link Variables to Controls

You can link variables to slider values and drop-down items to create dynamic controls.

To specify the minimum, maximum, and step values for a slider using variables, right-click the control and select Configure Control. Then, in the Values section, select a workspace variable for Min, Max, and Step. Only variables with numeric values appear in the drop-down list. If the variables that you want to select are not listed, try running the live script first to create the variables and add them to the workspace. Changes to the variables are automatically reflected in the numeric slider.

To populate the items in a drop-down list using the values stored in a variable, right-click the control and select Configure Control. Then, in the Items section, select a workspace variable from the Variable list. The variable must be a string array to appear in the list. If the variable that you want to select is not listed, try running the live script first to create the variable and add it to the workspace. Changes to the variable are automatically reflected in the drop-down list.

For example, create a live script and define the variable lastnames containing a list of last names.

lastnames = ["Houston","Vega","Obrien","Potter","Rivera","Hanson","Fowler","Tran","Briggs"];

Run the live script to create lastnames and add it to the workspace. Then, go to the Live Editor tab, and in the Code section, select Control > Drop Down. In the Items section of the control configuration menu, select lastnames as the Variable.

Drop-down list configuration menu with the lastnames variable selected and the lists of item labels and item values populated with the variable values

Close the configuration menu to return to the live script. The drop-down list now contains the last names defined in lastnames.

Drop-down list containing 9 last names

If you add, remove, or edit the values in lastnames, MATLAB® updates the items in the drop-down list accordingly.

Note

If the items in a drop-down list are linked to a variable, and one or more of the values in the variable are deleted while MATLAB is running, an error can occur if one of the deleted values was the selected list item. To prevent the error from occurring, avoid deleting values from a linked variable while the live script is running.

Specify Default Values

You can set the default value for sliders, drop-down lists, check boxes, and edit fields in live scripts.

To set the default value for a control, right-click the control and select Configure Control. Then, in the Defaults section, specify a default value by entering the value or by selecting a workspace variable from the list. The list shows only valid variables for the control. For drop-down lists, select the default value from the list of items.

To restore the default value for a control, right-click the control and select Restore Default Value.

Tip

To link the value of a control to a workspace variable, set the default value for the control to that variable. The control value is set to the default value and changes as the default value changes. The control value stays linked to the default value until the control value is changed manually, for example, by moving the slider thumb of a numeric slider.

Modify Control Execution

You can modify when and what code runs when the value of a control changes. By default, when the value of a control changes, the Live Editor runs the code in the current section. To configure this behavior, right-click the control and select Configure Control. Then, in the Execution section, modify the values of the fields described in the table below. Press Tab or Enter, or click outside of the control configuration menu to return to the live script.

FieldOptions
Run On (slider control only)

Select one of these options to specify when the code runs:

  • Value changing — Run the code while the value of the slider is changing.

  • Value changed — Run the code after the slider value is done changing (user has released the slider thumb).

Run

Select one of these options to specify what code runs when the value of the control changes:

  • Current section (Default) — Run the section that includes the control.

  • Current section and modified or not yet run sections above — Run the current section and any stale code above it when the control value changes. If the live script has not yet been run, changing the control value will run the current section and all sections before it.

  • Current section to end — Run the section that includes the control and any sections that follow.

  • All Sections — Run all sections in the live script.

  • Nothing — Do not run any code.

Tip

When using a button control in a live script, consider setting the Run field for all other controls in the live script to Nothing. Then, the code only runs when the user clicks the button control. This can be useful when the live script requires multiple control values to be set before running the code.

Create Live Script with Multiple Interactive Controls

This example shows how you can use interactive controls to visualize and investigate patient data in MATLAB®. The example plots the height versus the weight of either male or female patients, and highlights the patients over a specified height and weight.

To specify the gender of the patients to plot, insert a drop-down list and select the genderStrings variable to populate the items in the list. To specify a threshold height and weight, insert two numeric sliders and select the minHeight, maxHeight, minWeight, and maxWeight variables as the Min and Max values.

To view and interact with the controls, open this example in your browser or in MATLAB.

load patients
genderStrings = ["Female","Male"];

selectedGender = genderStrings(2);
minHeight = min(Height);
maxHeight = max(Height);
minWeight = min(Weight);
maxWeight = max(Weight);

thresholdHeight = 68;
thresholdWeight = 132;

overThresholdWeights = Weight(Gender==selectedGender & Weight>=thresholdWeight & Height>=thresholdHeight);
overThresholdHeights = Height(Gender==selectedGender & Weight>=thresholdWeight & Height>=thresholdHeight);

sp1 = scatter(Height(Gender==selectedGender),Weight(Gender==selectedGender),'blue');
hold on

sp2 = scatter(overThresholdHeights, overThresholdWeights,'red');
hold off

title('Height vs. Weight of ' + selectedGender + ' Patients')

legendText = sprintf('Patients over %d inches and %d pounds.',thresholdHeight,thresholdWeight);
legend(sp2,legendText,'Location','southoutside')

Figure contains an axes object. The axes object with title Height vs. Weight of Male Patients contains 2 objects of type scatter. This object represents Patients over 68 inches and 132 pounds..

Share Live Script

When the live script is complete, share it with others. Users can open the live script in MATLAB and experiment with using the controls interactively.

If you share the live script itself as an interactive document, consider hiding the code in the live script before sharing it. When the code is hidden, the Live Editor only displays labeled controls, output, and formatted text. To hide the code, click the hide code button to the right of the live script. You also can go to the View tab, and in the View section, click Hide Code.

If you share the live script as a static PDF, Microsoft® Word, HTML, or LaTeX document, the Live Editor saves the control as code. For example, in the live script shown here, the Live Editor replaces the slider controls with their current value (68 and 132) and replaces the drop-down control with the current value of the drop-down ("Female").

Related Topics