parsim

Simulate dynamic system multiple times in parallel or serial

Syntax

simOut = parsim(in)

simOut = parsim(in,'ShowSimulationManager','on')

simOut = parsim(in,Name,Value)

Description

simOut = parsim(in) simulates a model using the inputs specified in the SimulationInput object, in. The parsim command uses an array of SimulationInput objects to run multiple simulations.

simOut = parsim(in,'ShowSimulationManager','on') simulates a model in parallel using the inputs specified in the SimulationInput object and opens the Simulation Manager UI. For more information, see Simulation Manager.

simOut = parsim(in,Name,Value) simulates a model in parallel using the inputs specified in the SimulationInput object and the options specified as the Name,Value pair.

The parsim command uses the Parallel Computing Toolbox™ license to run the simulations in parallel. parsim runs the simulations in serial if a parallel pool cannot be created or if Parallel Computing Toolbox is not used.

Examples

Using parsim with Rapid Accelerator

Simulate the model, vdp, in rapid accelerator mode.

Load the model.

model = 'vdp';
load_system(model)

This step builds the Rapid Accelerator target

Simulink.BlockDiagram.buildRapidAcceleratorTarget(model);

Create a SimulationInput object and use setModelParameter method to set RapidAcceleratorUpToDateCheck to 'off'.

in = Simulink.SimulationInput(model);
in = in.setModelParameter('SimulationMode', 'rapid-accelerator');
in = in.setModelParameter('RapidAcceleratorUpToDateCheck', 'off');
 

Simulate the model.

out = parsim(in)

Simulate Model in Parallel with parsim

Simulate the model, CSTR, in parallel by sweeping over a variable. An array of SimulationInput objects is used to perform the sweep.

Specify sweep values.

FeedTempSweep = 250:10:300;

Create an array of SimulationInput objects.

for i = length(FeedTempSweep):-1:1
in(i) = Simulink.SimulationInput('CSTR');
in(i) = in(i).setVariable('FeedTemp0',FeedTempSweep(i));
end

Simulate the model in parallel.

out = parsim(in, 'ShowProgress', 'on')

[11-Dec-2020 09:14:55] Checking for availability of parallel pool...
Starting parallel pool (parpool) using the 'local' profile ...
Connected to the parallel pool (number of workers: 6).
[11-Dec-2020 09:15:43] Starting Simulink on parallel workers...
[11-Dec-2020 09:16:17] Configuring simulation cache folder on parallel workers...
[11-Dec-2020 09:16:17] Loading model on parallel workers...
[11-Dec-2020 09:16:25] Running simulations...
[11-Dec-2020 09:16:58] Completed 1 of 6 simulation runs
[11-Dec-2020 09:16:58] Completed 2 of 6 simulation runs
[11-Dec-2020 09:16:58] Completed 3 of 6 simulation runs
[11-Dec-2020 09:17:00] Completed 4 of 6 simulation runs
[11-Dec-2020 09:17:01] Completed 5 of 6 simulation runs
[11-Dec-2020 09:17:01] Completed 6 of 6 simulation runs
[11-Dec-2020 09:17:02] Cleaning up parallel workers...

out = 

1x6 Simulink.SimulationOutput array

Input Arguments

in — Simulink.SimulationInput object used to simulate the model

object, array

A Simulink.SimulationInput object or an array of Simulink.SimulationInput objects that is used to specify changes to the model for a simulation.

Example: in = Simulink.SimulationInput('vdp')

Name-Value Pair Arguments

Example: 'ShowProgress', 'on'

Note

All parameters passed to parsim command are unrelated to the parameters that are used with the sim command. To pass to the parsim command, use the list of following input arguments

Specify optional comma-separated pairs of Name,Value arguments. Name is the argument name and Value is the corresponding value. Name and Value must appear inside single quotes (' '). You can specify several name and value pair arguments in any order as Name1,Value1,...,NameN,ValueN.

'AttachedFiles' — Files to attach to parallel pool

cell array

Specified as a cell array of additional files to attach to the parallel pool.

'ShowProgress' — Show the progress of the simulations

'on'(default) | 'off'

Set to 'on', to see the progress of the simulations in the command window. The progress is hidden when set to 'off'.

Note

When the progress is shown, a message 'Cleaning up parallel workers..' may be displayed before the completion of the last few simulations. This message does not depend on the completion of the simulations. Simulations complete when the outputs are fetched from the future. For more information, see Simulink.Simulation.Future.

'RunInBackground' — Run simulations in background

'off' (default) | 'on'

Set to 'on' to run simulations asynchronously, keeping the MATLAB^® command prompt available for use.

'SetupFcn' — Function handle to run once per worker

function handle

Specify a function handle to 'SetupFcn' to run once per worker before the start of the simulations.

Example: 'SetupFcn',@()currentProject('Modelex/Model_example.prj')

Note

When buildRapidAcceleratorTarget is used in the SetupFcn and the model has external inputs specified,​ either set 'LoadExternalInput' to 'off' or ensure that the specified external input is available on the workers to prevent compilation error.

'CleanupFcn' — Function handle to run once per worker after running simulations

function handle

Specify a function handle to 'CleanupFcn' to run once per worker after the simulations are completed.

'ManageDependencies' — Manage model dependencies

'on' (default) | 'off'

When ManageDependencies is set to on, model dependencies are automatically sent to the parallel workers if required. If ManageDependencies is set to off, explicitly attach model dependencies to the parallel pool.

'UseFastRestart' — Use fast restart

'off' (default) | 'on'

When UseFastRestart is set to on, simulations run on the workers using fast restart.

When performing a parameter sweep varying properties of a Simscape™ component (e.g. mass and inertia of a Solid block in Simscape Multibody), specify the Simscape block parameter as run-time configurable. For more information, see About Simscape Run-Time Parameters (Simscape).

Note

When using parsim, use the UseFastRestart option and not the FastRestart option. See Get Started with Fast Restart for more information.

'TransferBaseWorkspaceVariables' — Transfer variables to the parallel workers

'off' (default) | 'on'

When TransferBaseWorkspaceVariables is set to on, variables used in the model and everything defined in the base workspace are transferred to the parallel workers.

'ShowSimulationManager' — Starts the Simulation Manager app

'off' (default) | 'on'

When 'ShowSimulationManager' is set to 'on', you can use the Simulation Manager App to monitor simulations.

'StopOnError' — Stop simulations on errors

'off' (default) | 'on'

Setting 'StopOnError' to 'on' stops the execution of simulations if an error is encountered.

Output Arguments

simOut — Simulation object containing logged simulation results

object

Array of Simulink.SimulationOutput objects that contains all of the logged simulation results. The size of the array is equal to the size of the array of Simulink.SimulationInput objects.

All simulation outputs (logged time, states, and signals) are returned in a single Simulink.SimulationOutput object. You define the model time, states, and output that is logged using the Data Import/Export pane of the Model Configuration Parameters dialog box. You can log signals using blocks such as the To Workspace and Scope blocks. The Signal & Scope Manager can directly log signals.

Extended Capabilities

Automatic Parallel Support

Accelerate code by automatically running computation in parallel using Parallel Computing Toolbox™.

If you have Parallel Computing Toolbox installed, then when you use parsim, MATLAB automatically opens a parallel pool of workers on your local machine. MATLAB runs the simulations across the available workers. Control parallel behavior with the parallel preferences, including scaling up to a cluster.

For details, see Run Multiple Simulations.