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matlablabview

How to call a Matlab function from Labview

I’m struggling to understand how to call a Matlab function from Labview. I’m using Labview 2020 SP1 and I’ve created the following m file (saved to my desktop):

function A = test()
A{1,1}=ones(1,3);
A{1,2}=ones(1,4);
end

In Labview I’ve added a Matlab script node and imported the function. However when I click run I get the following error:

Error occurred while executing script. Error message from server: ??? Error: Function definition not supported in this context. Functions can only be created as local or nested functions in code files.

I was expecting the function to be able to run but do nothing as I’ve not added any outputs to the Matlab script node.

Can anyone point me to where I’m going wrong? I’ve looked through the Labview examples but they only seem to demonstrate calling a Matlab script not a function.

Solution

  • Firstly the function would need to be in MATLAB's path (which typically wouldn't include the current user's desktop). MATLAB's path is a list of file locations that MATLAB will search in to find a function definition.

    You can view/edit the current path by typing pathtool into MATLAB's interactive command window which will bring up a GUI.

    Then your MATLAB script node should be able to call the function as below - note I have added an output just to check the result of the call.

    A snippet of LabVIEW code which calls the test function

    This image is a "LabVIEW Snippet" so you should be able to drag and drop it directly into the block diagram of a new VI and then save and run the VI.