Parallel Simulation Error using parfor and parpool

Hello,

I try to perform a simulation using the parfor command. My Simulink file changes data every 0.04s up to 3.84s (96 times total). I try to make my simulation a bit faster using parfor and parpool using essentially a timestep of 0.04s. Yet an error, which I quite frankly cannot understand pops out. By the way the simulation without parallel works perfectly. This is the code I use:

% Define the time step and simulation end time
timeStep = 0.04; % Time step (in seconds)
endTime = 3.84;  % End time (in seconds)

% Create a parallel pool if not already available
if isempty(gcp('nocreate'))
    parpool; % Create a parallel pool
end

% Define a function for simulating the Simulink model for a given time range
simFunc = @(startTime, endTime) simulink_simulation(startTime, endTime);

% Perform parallel simulations
simTimes = 0:timeStep:endTime;
numSimulations = length(simTimes);

parfor i = 1:numSimulations
    startTime = simTimes(i);
    endTime = startTime + timeStep;
    
    fprintf('Simulation %d: %.2f to %.2f seconds\n', i, startTime, endTime);
    
    % Call the simulation function for the current time range
    simFunc(startTime, endTime);
end

% Define the simulink_simulation function
function simulink_simulation(startTime, endTime)
    % Load the Simulink model
    model = 'zigzag_example_matlab';
    load_system(model);

    % Set the simulation time range
    set_param(model, 'StartTime', num2str(startTime));
    set_param(model, 'StopTime', num2str(endTime));

    % Run the simulation
    simOut = sim(model);
end

And this is the error that pops during simulation:

Simulation 2: 0.04 to 0.08 seconds

Simulation 6: 0.20 to 0.24 seconds

Simulation 8: 0.28 to 0.32 seconds

Simulation 4: 0.12 to 0.16 seconds

Warning: The file containing block diagram 'zigzag_example_matlab' has been changed on disk since it was loaded.

Warning: The file containing block diagram 'zigzag_example_matlab' has been changed on disk since it was loaded.

Warning: The file containing block diagram 'zigzag_example_matlab' has been changed on disk since it was loaded.

### Build procedure for zigzag_example_matlab aborted due to an error.

Build Summary

Top model rapid accelerator targets built:

Model Action Rebuild Reason

=================================================================================

zigzag_example_matlab Failed Code generation information file does not exist.

0 of 1 models built (0 models already up to date)

Warning: The file containing block diagram 'zigzag_example_matlab' has been changed on disk since it was loaded.

### Build procedure for zigzag_example_matlab aborted due to an error.

Build Summary

Top model rapid accelerator targets built:

Model Action Rebuild Reason

=================================================================================

zigzag_example_matlab Failed Code generation information file does not exist.

0 of 1 models built (0 models already up to date)

### Build procedure for zigzag_example_matlab aborted due to an error.

Build Summary

Top model rapid accelerator targets built:

Model Action Rebuild Reason

=================================================================================

zigzag_example_matlab Failed Code generation information file does not exist.

0 of 1 models built (0 models already up to date)

Build duration: 0h 0m 16.512s

### Build procedure for zigzag_example_matlab aborted due to an error.

Build Summary

Top model rapid accelerator targets built:

Model Action Rebuild Reason

=================================================================================

zigzag_example_matlab Failed Code generation information file does not exist.

0 of 1 models built (0 models already up to date)

Analyzing and transferring files to the workers ...done.

Simulation 8: 0.28 to 0.32 seconds

Simulation 6: 0.20 to 0.24 seconds

Warning: The file containing block diagram 'zigzag_example_matlab' has been changed on disk since it was loaded.

Simulation 4: 0.12 to 0.16 seconds

Simulation 2: 0.04 to 0.08 seconds

Warning: The file containing block diagram 'zigzag_example_matlab' has been changed on disk since it was loaded.

### Build procedure for zigzag_example_matlab aborted due to an error.

Build Summary

Top model rapid accelerator targets built:

Model Action Rebuild Reason

=================================================================================

zigzag_example_matlab Failed Code generation information file does not exist.

0 of 1 models built (0 models already up to date)

Warning: The file containing block diagram 'zigzag_example_matlab' has been changed on disk since it was loaded.

Warning: The file containing block diagram 'zigzag_example_matlab' has been changed on disk since it was loaded.

### Build procedure for zigzag_example_matlab aborted due to an error.

Build Summary

Top model rapid accelerator targets built:

Model Action Rebuild Reason

=================================================================================

zigzag_example_matlab Failed Code generation information file does not exist.

0 of 1 models built (0 models already up to date)

### Build procedure for zigzag_example_matlab aborted due to an error.

Build Summary

Top model rapid accelerator targets built:

Model Action Rebuild Reason

=================================================================================

zigzag_example_matlab Failed Code generation information file does not exist.

0 of 1 models built (0 models already up to date)

Build duration: 0h 0m 3.7802s

### Build procedure for zigzag_example_matlab aborted due to an error.

Build Summary

Top model rapid accelerator targets built:

Model Action Rebuild Reason

=================================================================================

zigzag_example_matlab Failed Code generation information file does not exist.

0 of 1 models built (0 models already up to date)

Build duration: 0h 0m 3.7551s

Build duration: 0h 0m 3.8837s

Build duration: 0h 0m 3.886s

Error using Parallel_Simulation_Script>simulink_simulation

Unable to build a standalone executable to simulate the model 'zigzag_example_matlab' in rapid accelerator mode.

Error in Parallel_Simulation_Script>@(startTime,endTime)simulink_simulation(startTime,endTime) (line 11)

simFunc = @(startTime, endTime) simulink_simulation(startTime, endTime);

Error in Parallel_Simulation_Script (line 17)

parfor i = 1:numSimulations

Caused by:

Error using Parallel_Simulation_Script>simulink_simulation

Error due to multiple causes.

Error using Parallel_Simulation_Script>simulink_simulation

Invalid setting in 'zigzag_example_matlab/Branch1' for parameter 'SampleTime'.

Error using Parallel_Simulation_Script>simulink_simulation

Error evaluating parameter 'SampleTime' in 'zigzag_example_matlab/Branch1'

Error using Parallel_Simulation_Script>simulink_simulation

Unrecognized function or variable 'time'.

Error using Parallel_Simulation_Script>simulink_simulation

Variable 'time' has been deleted from base workspace.

Error using Parallel_Simulation_Script>simulink_simulation

Invalid setting in 'zigzag_example_matlab/Branch2' for parameter 'SampleTime'.

Error using Parallel_Simulation_Script>simulink_simulation

Error evaluating parameter 'SampleTime' in 'zigzag_example_matlab/Branch2'

Error using Parallel_Simulation_Script>simulink_simulation

Unrecognized function or variable 'time'.

Error using Parallel_Simulation_Script>simulink_simulation

Variable 'time' has been deleted from base workspace.

Error using Parallel_Simulation_Script>simulink_simulation

Invalid setting in 'zigzag_example_matlab/Branch3' for parameter 'SampleTime'.

Error using Parallel_Simulation_Script>simulink_simulation

Error evaluating parameter 'SampleTime' in 'zigzag_example_matlab/Branch3'

Error using Parallel_Simulation_Script>simulink_simulation

Unrecognized function or variable 'time'.

Error using Parallel_Simulation_Script>simulink_simulation

Variable 'time' has been deleted from base workspace.

Error using Parallel_Simulation_Script>simulink_simulation

Invalid setting in 'zigzag_example_matlab/Branch4' for parameter 'SampleTime'.

Error using Parallel_Simulation_Script>simulink_simulation

Error evaluating parameter 'SampleTime' in 'zigzag_example_matlab/Branch4'

Error using Parallel_Simulation_Script>simulink_simulation

Unrecognized function or variable 'time'.

Error using Parallel_Simulation_Script>simulink_simulation

Variable 'time' has been deleted from base workspace.

Error using Parallel_Simulation_Script>simulink_simulation

Invalid setting in 'zigzag_example_matlab/Branch5' for parameter 'SampleTime'.

Error using Parallel_Simulation_Script>simulink_simulation

Error evaluating parameter 'SampleTime' in 'zigzag_example_matlab/Branch5'

Error using Parallel_Simulation_Script>simulink_simulation

Unrecognized function or variable 'time'.

Error using Parallel_Simulation_Script>simulink_simulation

Variable 'time' has been deleted from base workspace.

Error using Parallel_Simulation_Script>simulink_simulation

Invalid setting in 'zigzag_example_matlab/From Workspace' for parameter 'VariableName'.

Error using Parallel_Simulation_Script>simulink_simulation

Error evaluating parameter 'VariableName' in 'zigzag_example_matlab/From Workspace'

Error using Parallel_Simulation_Script>simulink_simulation

Unrecognized function or variable 'SR888700131'.

Error using Parallel_Simulation_Script>simulink_simulation

Variable 'SR888700131' has been deleted from base workspace.

Error using Parallel_Simulation_Script>simulink_simulation

Invalid setting in 'zigzag_example_matlab/From Workspace1' for parameter 'VariableName'.

Error using Parallel_Simulation_Script>simulink_simulation

Error evaluating parameter 'VariableName' in 'zigzag_example_matlab/From Workspace1'

Error using Parallel_Simulation_Script>simulink_simulation

Unrecognized function or variable 'SA888700131'.

Error using Parallel_Simulation_Script>simulink_simulation

Variable 'SA888700131' has been deleted from base workspace.

Error using Parallel_Simulation_Script>simulink_simulation

Invalid setting in 'zigzag_example_matlab/From Workspace10' for parameter 'VariableName'.

Error using Parallel_Simulation_Script>simulink_simulation

Error evaluating parameter 'VariableName' in 'zigzag_example_matlab/From Workspace10'

Error using Parallel_Simulation_Script>simulink_simulation

Unrecognized function or variable 'R888700022'.

Error using Parallel_Simulation_Script>simulink_simulation

Variable 'R888700022' has been deleted from base workspace.

Error using Parallel_Simulation_Script>simulink_simulation

Invalid setting in 'zigzag_example_matlab/From Workspace11' for parameter 'VariableName'.

Error using Parallel_Simulation_Script>simulink_simulation

Error evaluating parameter 'VariableName' in 'zigzag_example_matlab/From Workspace11'

Error using Parallel_Simulation_Script>simulink_simulation

Unrecognized function or variable 'Load888700022'.

Error using Parallel_Simulation_Script>simulink_simulation

Variable 'Load888700022' has been deleted from base workspace.

Error using Parallel_Simulation_Script>simulink_simulation

Invalid setting in 'zigzag_example_matlab/From Workspace2' for parameter 'VariableName'.

Error using Parallel_Simulation_Script>simulink_simulation

Error evaluating parameter 'VariableName' in 'zigzag_example_matlab/From Workspace2'

Error using Parallel_Simulation_Script>simulink_simulation

Unrecognized function or variable 'R888700021'.

Error using Parallel_Simulation_Script>simulink_simulation

Variable 'R888700021' has been deleted from base workspace.

Error using Parallel_Simulation_Script>simulink_simulation

Invalid setting in 'zigzag_example_matlab/From Workspace3' for parameter 'VariableName'.

Error using Parallel_Simulation_Script>simulink_simulation

Error evaluating parameter 'VariableName' in 'zigzag_example_matlab/From Workspace3'

Error using Parallel_Simulation_Script>simulink_simulation

Unrecognized function or variable 'Load888700021'.

Error using Parallel_Simulation_Script>simulink_simulation

Variable 'Load888700021' has been deleted from base workspace.

Error using Parallel_Simulation_Script>simulink_simulation

Invalid setting in 'zigzag_example_matlab/From Workspace4' for parameter 'VariableName'.

Error using Parallel_Simulation_Script>simulink_simulation

Error evaluating parameter 'VariableName' in 'zigzag_example_matlab/From Workspace4'

Error using Parallel_Simulation_Script>simulink_simulation

Unrecognized function or variable 'R888700024'.

Error using Parallel_Simulation_Script>simulink_simulation

Variable 'R888700024' has been deleted from base workspace.

Error using Parallel_Simulation_Script>simulink_simulation

Invalid setting in 'zigzag_example_matlab/From Workspace5' for parameter 'VariableName'.

Error using Parallel_Simulation_Script>simulink_simulation

Error evaluating parameter 'VariableName' in 'zigzag_example_matlab/From Workspace5'

Error using Parallel_Simulation_Script>simulink_simulation

Unrecognized function or variable 'Load888700024'.

Error using Parallel_Simulation_Script>simulink_simulation

Variable 'Load888700024' has been deleted from base workspace.

Error using Parallel_Simulation_Script>simulink_simulation

Invalid setting in 'zigzag_example_matlab/From Workspace6' for parameter 'VariableName'.

Error using Parallel_Simulation_Script>simulink_simulation

Error evaluating parameter 'VariableName' in 'zigzag_example_matlab/From Workspace6'

Error using Parallel_Simulation_Script>simulink_simulation

Unrecognized function or variable 'R888700103'.

Error using Parallel_Simulation_Script>simulink_simulation

Variable 'R888700103' has been deleted from base workspace.

Error using Parallel_Simulation_Script>simulink_simulation

Invalid setting in 'zigzag_example_matlab/From Workspace7' for parameter 'VariableName'.

Error using Parallel_Simulation_Script>simulink_simulation

Error evaluating parameter 'VariableName' in 'zigzag_example_matlab/From Workspace7'

Error using Parallel_Simulation_Script>simulink_simulation

Unrecognized function or variable 'Load888700103'.

Error using Parallel_Simulation_Script>simulink_simulation

Variable 'Load888700103' has been deleted from base workspace.

Error using Parallel_Simulation_Script>simulink_simulation

Invalid setting in 'zigzag_example_matlab/From Workspace8' for parameter 'VariableName'.

Error using Parallel_Simulation_Script>simulink_simulation

Error evaluating parameter 'VariableName' in 'zigzag_example_matlab/From Workspace8'

Error using Parallel_Simulation_Script>simulink_simulation

Unrecognized function or variable 'R888700026'.

Error using Parallel_Simulation_Script>simulink_simulation

Variable 'R888700026' has been deleted from base workspace.

Error using Parallel_Simulation_Script>simulink_simulation

Invalid setting in 'zigzag_example_matlab/From Workspace9' for parameter 'VariableName'.

Error using Parallel_Simulation_Script>simulink_simulation

Error evaluating parameter 'VariableName' in 'zigzag_example_matlab/From Workspace9'

Error using Parallel_Simulation_Script>simulink_simulation

Unrecognized function or variable 'Load888700026'.

Error using Parallel_Simulation_Script>simulink_simulation

Variable 'Load888700026' has been deleted from base workspace.

Does anyone have any idea what I need to do in order to fix it?

Answer 1

[Raymond Norris]

Rather than parfor, you might consider looking at parsim.

[Dimosthenis Michaloudis]

Using parsim also provided me with errors, that as I tried to fix went on and on.