Hi,
As per my understanding, you are facing an undefined function error for DispatchInBackgroundDatastore while following the example Gesture Recognition using Videos and Deep Learning.
‘DispatchInBackgroundDatastore’ is not a MATLAB function, but is provided as a part of this example, as mentioned in ‘Specify Training Options’ subsection of ‘Train a Video Classifier for Gesture Recognition’ section. In order to avoid the undefined function error, you can open the example in MATLAB by typing the following in the Command Window,
openExample('deeplearning_shared/GestureRecognitionUsingSlowFastVideoClassificationExample')
This will add the ‘DispatchInBackgroundDatastore’ to the path.