Simulink.sdi.sendWorkerRunToClient

Setup

This example runs several simulations of the vdp model, varying the value of the Gain block, Mu. To set up for the parallel simulation, define a vector of Mu values and configure the Simulation Data Inspector for manual Parallel Computing Toolbox support.

MuVals = [0.1 0.2 0.3 0.4];
Simulink.sdi.enablePCTSupport("manual");

Initialize Parallel Workers

Use parpool (Parallel Computing Toolbox) to start a pool of four parallel workers. This example calls parpool inside an if statement so you only create a parallel pool if you do not already have one.

p = gcp("nocreate");
if isempty(p)
    parpool(4);
end

You can use spmd (Parallel Computing Toolbox) to run initialization code common to all workers. For example, load the vdp model and Simulink.sdi.markSignalForStreaming function to select signals to log to the Simulation Data Inspector. To avoid data concurrency issues when simulating with sim in parfor, create a temporary directory on each worker.

spmd
    load_system("vdp")
    Simulink.sdi.markSignalForStreaming("vdp/x1",1,"on")
    Simulink.sdi.markSignalForStreaming("vdp/x2",1,"on")
    
    workDir = pwd;
    addpath(workDir)
    tempDir = tempname;
    mkdir(tempDir)
    cd(tempDir)
end

Run Parallel Simulations with parfor

To stream data from parallel workers to the Simulation Data Inspector, run parallel simulations using parfor (Parallel Computing Toolbox). Each worker runs a vdp simulation with a different value of Mu. The software cannot access the contents of the parfor loop, so the variable MuVal is defined in the worker's workspace, where the vdp model can see it, using assignin.

parfor (index = 1:4)
    assignin("base","MuVal",MuVals(index));
    set_param("vdp/Mu","Gain","MuVal")
    sim("vdp");

Access Data and Send Run to Client MATLAB

You can use the Simulation Data Inspector programmatic interface on the worker the same way you would in the client MATLAB. This example creates a Simulink.sdi.Run object and attaches the value of Mu used in the simulation with the Tag property.

    IDs = Simulink.sdi.getAllRunIDs;
    lastIndex = length(IDs);
    runID = Simulink.sdi.getRunIDByIndex(lastIndex);
    parRun = Simulink.sdi.getRun(runID);
    parRun.Tag = strcat("Mu = ",num2str(MuVals(index)));
    
    Simulink.sdi.sendWorkerRunToClient   
end

Close Temporary Directories and View Runs in the Simulation Data Inspector

Use another spmd section to delete the temporary directories created on the workers once the simulations complete.

spmd
    cd(workDir)
    rmdir(tempDir,"s")
    rmpath(workDir)
end

In each simulation, the Simulink.sdi.sendWorkerRunToClient function imported runs from all the workers into the Simulation Data Inspector. You can view the data and check the run properties to see the value of Mu used during simulation.

Simulink.sdi.view