Unstack Table Variables

Distribute values from one table variable to multiple table variables in the Live Editor

Description

The Unstack Table Variables task lets you interactively unstack, or distribute, values in a table or timetable from one variable to multiple variables. The task also automatically generates MATLAB^® code for your live script.

To unstack variables means to distribute values from specified variables into multiple variables of the output. You must specify that one input variable is the indicator variable, whose unique values indicate the corresponding variables of the output. Other variables of the input can be grouping variables or constant variables, whose values determine the rows of the output. The diagram shows the result of unstacking a table using indicator and grouping variables.

For more information on Live Editor tasks, see Add Interactive Tasks to a Live Script.

Related Functions

Unstack Table Variables generates code that uses the unstack function.

Open the Task

To add the Unstack Table Variables task to a live script in the MATLAB Editor:

• On the Live Editor tab, select Task > Unstack Table Variables.

• Or, in a code block in the script, type a relevant keyword, such as unstack. Select Unstack Table Variables from the suggested command completions.

Examples

Unstack Table Variable Using Live Editor Task

This example shows how to unstack values from one variable in an input table and distribute them to multiple variables in an output table by using the Unstack Table Variables Live Editor task.

First, load a table from a sample file that lists the number of power company customers who experienced electric power outages. The table lists the number of customers by month and by region of the United States.

load customersOutage.mat
customersOutage

customersOutage=18×3 table
        Month         Region      CustomersOutage
    _____________    _________    _______________

     October-2023    NorthEast          3492     
     October-2023    MidWest             565     
     October-2023    SouthEast          1027     
    November-2023    NorthEast          2944     
    November-2023    MidWest            1293     
    November-2023    SouthEast           834     
    December-2023    NorthEast          2559     
    December-2023    MidWest             936     
    December-2023    SouthEast          1412     
     January-2024    NorthEast         12045     
     January-2024    MidWest           50117     
     January-2024    SouthEast             0     
    February-2024    NorthEast          4931     
    February-2024    MidWest            1089     
    February-2024    SouthEast           137     
       March-2024    NorthEast          3018     
      ⋮

Add the Unstack Table Variables task to your live script. Unstack the CustomersOutage variable so that the output table has variables named NorthEast, MidWest, and SouthEast.

• To group the data by month, select the Group by menu item below the Month variable in the task.

• To select the names of the output variables, click the radio button Names of new table variables above the Region variable. For each unique value in Region, there is a corresponding variable in the output table.

• To distribute values from the CustomersOutage variable into the NorthEast, Midwest, and SouthEast variables in the output, click the radio button Values in new table variables above CustomersOutage.

unstackedTable=6×4 table
        Month        NorthEast    MidWest    SouthEast
    _____________    _________    _______    _________

     October-2023       3492         565       1027   
    November-2023       2944        1293        834   
    December-2023       2559         936       1412   
     January-2024      12045       50117          0   
    February-2024       4931        1089        137   
       March-2024       3018         942        870   

Related Examples

• Add Interactive Tasks to a Live Script

Parameters

Input table — Name of table or timetable

drop-down list item

Specify the name of the input table or timetable from the list of all the nonempty tables and timetables that are in the workspace.

Names of new table variables — Input variable that has names of output variables

radio button

Specify the names of new table variables in the output by clicking the radio button for a variable in the input. For each unique value in the input variable, there is a corresponding variable in the output.

Values in new table variables — Input table variable that provides values to output table variables

radio button

Specify the values in new table variables in the output by clicking the radio button for a variable in the input. The values in the selected input variable are aggregated using the selected aggregator function. Then the aggregated values are distributed into the variables in the output.

Aggregator for new table variable values — Function that aggregates values in input variables

drop-down list item

Specify the function that aggregates values from the selected input variable from the list of functions.

Version History

Introduced in R2020a

R2024a: Generate template code for custom aggregation function

When you select the Custom function option for the Aggregator for new table variable values method, you can generate template code that can help you write your own custom aggregation function.

1. Select Custom function.

2. Select Local function from the next menu.

3. Click New to add a new local function to the script.

4. Select the name of the new local function from the next menu.

The live task generates template code and places it within the live script. To customize this code, edit it in the live script.

R2022a: Live Editor task does not run automatically if inputs have more than 1 million elements

This Live Editor task does not run automatically if the inputs have more than 1 million elements. In previous releases, the task always ran automatically for inputs of any size. If the inputs have a large number of elements, then the code generated by this task can take a noticeable amount of time to run (more than a few seconds).

When a task does not run automatically, the Autorun indicator is disabled. You can either run the task manually when needed or choose to enable the task to run automatically.