Why Matlab throw an "Unrecognized function or variable 'splitEachLabel" error?

I'm making a custom loop for training a neural network. When I was trying to use the "splitEachLabel" function for splitting the datastore, I got an error:

[imdsTrain, imdsVal] = splitEachLabel(imds,0.8,'randomize');

"Unrecognized function or variable 'splitEachLabel'."

I checked if I have toolboxes that are needed for the project and if this function exists .

>> ver
-----------------------------------------------------------------------------------------------------
MATLAB Version: 25.2.0.2998904 (R2025b)
Operating System: Microsoft Windows 10 Home Version 10.0 (Build 19045)
Java Version: Java 1.8.0_202-b08 with Oracle Corporation Java HotSpot(TM) 64-Bit Server VM mixed mode
-----------------------------------------------------------------------------------------------------
MATLAB                                                Version 25.2        (R2025b)
Simulink                                              Version 25.2        (R2025b)
Computer Vision Toolbox                               Version 25.2        (R2025b)
Control System Toolbox                                Version 25.2        (R2025b)
Deep Learning HDL Toolbox                             Version 25.2        (R2025b)
Deep Learning Toolbox                                 Version 25.2        (R2025b)
Embedded Coder                                        Version 25.2        (R2025b)
Image Processing Toolbox                              Version 25.2        (R2025b)
MATLAB Coder                                          Version 25.2        (R2025b)
Parallel Computing Toolbox                            Version 25.2        (R2025b)
Statistics and Machine Learning Toolbox               Version 25.2        (R2025b)
Symbolic Math Toolbox                                 Version 25.2        (R2025b)
>> which splitEachLabel -all
'splitEachLabel' not found.

I also run in command line:

run restoredefaultpath; rehash toolboxcache

because that was suggested by Copilot. That didn't help.

[Torsten]

My guess is that you need the Audio Toolbox to use the function:

which splitEachLabel

/MATLAB/toolbox/audio/audio/@audioDatastore/splitEachLabel.m  % audioDatastore method

[~, products] = matlab.codetools.requiredFilesAndProducts('splitEachLabel.m')

products = 1×2 struct array with fields:
    Name
    Version
    ProductNumber
    Certain

products.Name

ans = 'MATLAB'

ans = 'Audio Toolbox'

[Haelee]

If you are using an ImageDatastore object for the first parameter, you should be able to use the "splitEachLabel" function regardless of Audio Toolbox because it is a built-in object function.

May I ask you if you're unable to run this example also?

imds = imageDatastore(fullfile(matlabroot, 'toolbox', 'matlab', {'demos'}),...

'LabelSource', 'foldernames', 'FileExtensions', {'.jpg', '.png', '.tif'});

imds.Labels

[imds60, imds40] = splitEachLabel(imds,0.6,'Include','demos')