sim

R2026b

Run and script programmatic simulations of Simulink models

collapse all in page

Syntax

out = sim(simin)
out = sim(simin,Name=Value)
out = sim(mdl)
out = sim(mdl,Name=Value)
out = sim(mdl,params)
out = sim(mdl,configset)

Description

Simulink.SimulationInput Object Syntax

out = sim(simin) runs one or more simulations of a Simulink® model according to the properties defined on one or more Simulink.SimulationInput objects.

  • If simin is a scalar Simulink.SimulationInput object, then out is a scalar Simulink.SimulationOutput object.

  • If simin is a vector, matrix, or array of Simulink.SimulationInput objects, then out is a vector, matrix, or array of Simulink.SimulationOutput objects with the same dimensions as simin.

You can use a Simulink.SimulationInput object to configure options and inputs for simulations, including:

  • The model to simulate

  • Source variables or files for external input data

  • Block parameter values to use for the simulation

  • Model configuration parameter values to use for the simulation

When a property of the Simulink.SimulationInput object modifies a model or block parameter value, the value is modified during simulation and reverted at the end of the simulation.

When you configure programmatic simulations using Simulink.SimulationInput objects, you can transition from using the sim function to using other functions, such as parsim and batchsim.

For more information, see Run Simulations Programmatically.

example

out = sim(simin,Name=Value) runs the simulations with additional options specified using one or more name-value arguments.

For a list of name-value arguments supported by the Simulink.SimulationInput syntax, see Simulink.SimulationInput Object Syntax.

example

Model Syntax

out = sim(mdl) simulates the model mdl using the current configuration parameter and block parameter values specified in the model.

example

out = sim(mdl,Name=Value) simulates the model with options specified using one or more name-value arguments. For example, you can modify a model configuration parameter value for the simulation by specifying the parameter name and value as a name-value argument.

When you modify model configuration parameters by providing inputs to the sim function, the changes are applied during simulation and reverted at the end of the simulation.

For a list of name-value arguments supported for the model syntax, see Model Syntax.

out = sim(mdl,params) simulates the model using the model configuration parameter values specified by the structure params.

example

out = sim(mdl,configset) simulates the model using model configuration parameter values in the configuration set configset.

example

Examples

collapse all

Suppose you have a model named IntegrateSine that integrates the output of a Sine Wave block and logs the result using an Outport block. A Scope block displays the sine wave input and the integrated output. You open the model and want to simulate the model using the parameter values saved in the model.

Block diagram of the model IntegrateSine.

Simulate the model by specifying the name of the model as input to the sim function.

out = sim(mdl);

The simulation runs using the current model configuration parameters and block parameters specified in the model. In this case, the model has a stop time of 10 seconds, and the amplitude of the Sine Wave block is 1.

The sine wave input and integrated output displayed on a Scope block.

To modify parameters in a model for simulation without dirtying the model, use a Simulink.SimulationInput object to configure the simulation. When you configure simulations using Simulink.SimulationInput objects, you can configure model configuration parameter, block parameter, and variable values. The sim function applies the configuration specified on the Simulink.SimulationInput object during the simulation and reverts changes to the model when the simulation completes.

Suppose you want to simulate the model IntegrateSine described in Run Simulations Using Current Parameter Values for different amplitudes of the sine wave input.

Block diagram of the model IntegrateSine.

To parameterize the model, specify the value of the Sine Wave block Amplitude parameter as a variable. Open the model. Then, define the variable in the base workspace and specify the value of the block parameter in the model as the variable.

mdl = "IntegrateSine";
open_system(mdl)
a = 1;
set_param(mdl + "/Sine Wave",Amplitude="a")

Create a Simulink.SimulationInput object to store the simulation configuration. Specify parameter and variable values on the Simulink.SimulationInput object to configure a simulation that:

  • Uses the solver ode45

  • Runs through a stop time of 20 seconds

  • Sets the amplitude of the simulated sine wave input to 2

mdl = "IntegrateSine";
simin = Simulink.SimulationInput(mdl);
simin = setModelParameter(simin,Solver="ode45",StopTime="20");
simin = setVariable(simin,"a",2);

Simulate the model by specifying the Simulink.SimulationInput object as input to the sim function.

out = sim(simin);

The model simulates for 20 seconds, using the solver ode45 and a sine wave amplitude of 2.

The sine wave input and integrated output displayed on a Scope block.

After the simulation completes, the variable in the workspace, the solver parameter, and the stop time parameter revert to their original values.

Fast restart speeds up parameter sweeps by compiling the model only once, before the execution phase of the first simulation. Each subsequent simulation reinitializes the model with specified parameter values without recompiling the model, which can significantly reduce the overall time required to run the parameter sweep. To enable fast restart for parameter sweeps run using a single call to the sim function, specify the UseFastRestart name-value argument as "on".

Suppose you want to simulate the model IntegrateSine described in Run Simulations Using Current Parameter Values for different amplitudes of the sine wave input.

Block diagram of the model IntegrateSine.

To parameterize the model, specify the value of the Sine Wave block Amplitude parameter as a variable. Open the model. Then, define the variable in the base workspace and specify the value of the block parameter in the model as the variable.

mdl = "IntegrateSine";
open_system(mdl)
a = 1;
set_param(mdl + "/Sine Wave",Amplitude="a")

Create a vector of the parameter values you want to simulate. Then, create an array of Simulink.SimulationInput objects that represent the configuration for each simulation in the parameter sweep. In a for loop, specify the value of the variable that defines the parameter on each Simulink.SimulationInput object.

mdl = "IntegrateSine";
amps = [1 2 3 4 5 6];
n = length(amps);
simin(1:n) = Simulink.SimulationInput(mdl);

for k = n:-1:1
    simin(k) = setVariable(simin(k),"a",amps(k));
end

Run the parameter sweep using a single call to the sim function that enables fast restart by specifying the UseFastRestart name-value argument as "on".

out = sim(simin,UseFastRestart="on");
[14-Apr-2026 17:31:23] Running simulations...
[14-Apr-2026 17:31:24] Completed 1 of 6 simulation runs
[14-Apr-2026 17:31:25] Completed 2 of 6 simulation runs
[14-Apr-2026 17:31:25] Completed 3 of 6 simulation runs
[14-Apr-2026 17:31:25] Completed 4 of 6 simulation runs
[14-Apr-2026 17:31:26] Completed 5 of 6 simulation runs
[14-Apr-2026 17:31:26] Completed 6 of 6 simulation runs

The sim function returns the simulation results as an array of Simulink.SimulationOutput objects. Each Simulink.SimulationOutput object in the array contains the results for the simulation configured using the Simulink.SimulationInput object with the same index in the input array. For example, the Simulink.SimulationOutput object at index 1 in the output array contains the results for the simulation run using the Simulink.SimulationInput object at index 1 in the input array.

Access the output data logged in the first simulation, which used an amplitude of 1.

yout1 = out(1).yout
yout1 = 
Simulink.SimulationData.Dataset 'yout' with 1 element

                         Name    BlockPath             
                         ______  _____________________ 
    1  [1x1 Signal]      output  IntegrateSine/Outport

  - Use braces { } to access, modify, or add elements using index.

To suppress the progress messages, specify the ShowProgress name-value argument as "off". To monitor progress using the Simulation Manager, specify the ShowSimulationManager name-value argument as "on". For more information, see Simulation Manager.

To configure simulations without dirtying the model, you can specify one or more name-value arguments. The sim function modifies the parameters during simulation and reverts changes to the model when the simulation completes. Name-value arguments can specify only model configuration parameters. To configure additional parameters, such as variable and block parameter values, use a Simulink.SimulationInput object instead.

Suppose you want to simulate the model IntegrateSine, described in Run Simulations Using Current Parameter Values, for 20 seconds using the solver ode45.

Block diagram of the model IntegrateSine.

Simulate the model. Specify the Stop time and Solver parameters for the simulation using name-value arguments.

mdl = "IntegrateSine";
out = sim(mdl,StopTime="20",Solver="ode45");

To see the parameter values used in the simulation, check the simulation metadata returned with the simulation results.

slvr = out.SimulationMetadata.ModelInfo.SolverInfo.Solver
slvr =

    'ode45'
tstop = out.SimulationMetadata.ModelInfo.StopTime
tstop =

    20

To configure simulations without dirtying the model, you can specify a structure that defines the name and value of each parameter you want to modify. The sim function modifies the specified parameters during simulation and reverts changes to the model when the simulation completes. The structure can specify only model configuration parameters. To configure additional parameters, such as variable and block parameter values, use a Simulink.SimulationInput object instead.

Suppose you want to simulate the model IntegrateSine, described in Run Simulations Using Current Parameter Values, for 20 seconds using the solver ode45.

Block diagram of the model IntegrateSine.

Create a structure that contains the fields Solver and StopTime.

simconfig.Solver = "ode45";
simconfig.StopTime = "20";

Simulate the model using the parameter values specified in the structure.

mdl = "IntegrateSine";
out = sim(mdl,simconfig);

To see the parameter values used in the simulation, check the simulation metadata returned with the simulation results.

slvr = out.SimulationMetadata.ModelInfo.SolverInfo.Solver
slvr =

    'ode45'
tstop = out.SimulationMetadata.ModelInfo.StopTime
tstop =

    20

To apply a configuration set to a simulation without dirtying the model, configure the simulation using a Simulink.ConfigSet object. The sim function applies the configuration set to the model during simulation and reverts the change when the simulation completes. A configuration set specifies only model configuration parameter values. To specify additional values, such as variable and block parameter values, use a Simulink.SimulationInput object instead.

Suppose you want to simulate the model IntegrateSine, described in Run Simulations Using Current Parameter Values, for 20 seconds using the solver ode45.

Block diagram of the model IntegrateSine.

To specify the parameter values to use in the simulation, create and configure a Simulink.ConfigSet object. Open the model and get the current configuration set. Then, create a copy of the configuration set and specify the stop time and solver on the copy.

mdl = "IntegrateSine";
open_system(mdl)
mdlconfig = getActiveConfigSet(mdl);
simconfig = copy(mdlconfig);
set_param(simconfig,StopTime="20");
set_param(simconfig,Solver="ode45");

Simulate the model using the configuration set simconfig.

out = sim(mdl,simconfig);

To see the parameter values used in the simulation, check the simulation metadata returned with the simulation results.

slvr = out.SimulationMetadata.ModelInfo.SolverInfo.Solver
slvr =

    'ode45'
tstop = out.SimulationMetadata.ModelInfo.StopTime
tstop =

    20

Input Arguments

collapse all

Simulation inputs and configuration, specified as a Simulink.SimulationInput object or an array of Simulink.SimulationInput objects. The properties of the Simulink.SimulationInput object specify options and parameter values to use in the simulation, including:

  • The model to simulate

  • Source variables or files for external input data

  • Block parameter values to use for the simulation

  • Model configuration parameter values to use for the simulation

The values defined in the properties of the Simulink.SimulationInput object are applied to the model for the simulation and reverted at the end of simulation.

Model to simulate, specified as a string or a character vector that defines the name of the model or as a model handle (since R2024a).

Example: out = sim("vdp") simulates the model named vdp using the parameter values currently configured in the model.

Data Types: char | string

Model parameter values to use in simulation, specified as a structure. To specify a parameter value, add a field to the structure that matches the programmatic name of the model parameter. For example, to specify a start time of 5 seconds and a stop time of 10 seconds, create this structure:

params.StartTime = "5";
params.StopTime = "10";

Data Types: struct

Configuration set to use in simulation, specified as a Simulink.ConfigSet object.

Name-Value Arguments

expand all

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Example: out = sim(simin,UseFastRestart="on") runs a set of simulations using fast restart.

Example: out = sim(mdl,FastRestart="on") enables fast restart and runs a simulation of the model mdl.

Note

The sim function supports different name-value arguments depending on whether you specify the first input as one or more Simulink.SimulationInput objects or as the name or handle of the model to simulate.

Simulink.SimulationInput Object Syntax

expand all

Option to enable fast restart, specified as "off" or "on". Fast restart reduces the time required to run a set of simulations by compiling the model only once, before the execution phase of the first simulation. For more information, see How Fast Restart Improves Iterative Simulations.

Consider using fast restart when you run multiple simulations of a model by specifying an array of Simulink.SimulationInput objects. For more information, see Script Iterative or Batch Simulations Using Fast Restart.

This argument is supported only when you specify the first input to the sim function as one or more Simulink.SimulationInput objects.

This argument has no effect when you specify a scalar Simulink.SimulationInput object. To enable fast restart, specify the FastRestart parameter on the Simulink.SimulationInput object using the setModelParameter function. When you enable fast restart using a scalar Simulink.SimulationInput object, fast restart remains enabled in the model after the simulation completes.

Example: out = sim(simin,UseFastRestart="on");

Data Types: char | string

Option to skip subsequent simulations if simulation error occurs, specified as "off" or "on".

  • "off" — If a simulation error occurs, the software captures the error in the simulation output and continues to run any subsequent simulations.

    For example, suppose you run five simulations using an array of Simulink.SimulationInput objects. An error occurs during the second simulation. The sim function captures the error in the output for the second simulation and continues to run the third, fourth, and fifth simulations.

  • "on" — If a simulation error occurs, the software captures the error in the simulation output and does not run any subsequent simulations.

    For example, suppose you run five simulations using an array of five Simulink.SimulationInput objects. An error occurs during the second simulation. The software captures the error in the output for the second simulation and does not run the third, fourth, and fifth simulations. The sim function returns an empty Simulink.SimulationOutput object for each simulation that does not run.

This argument has no effect when you specify the first input to the sim function as a scalar Simulink.SimulationInput object. (since R2024a)

This argument is supported only when you specify the first input to the sim function as one or more Simulink.SimulationInput objects.

Example: out = sim(simin,StopOnError="on");

Tips

  • When the first input is an array of Simulink.SimulationInput objects, the sim function always enables CaptureErrors for each simulation.

  • View information about captured errors in the simulation output and metadata.

    • The sim function captures the error in the ErrorMessage property of the Simulink.SimulationOutput object.

      msg = out.ErrorMessage;

    • To view the error message in the Diagnostic Viewer, use the sldiagviewer.reportSimulationMetadataDiagnostics function.

      sldiagviewer.reportSimulationMetadataDiagnostics(out)

    • The Simulink.SimulationMetadata object returned by the simulation contains additional information about the error, such as the simulation phase in which the error occurred. The error information is stored in the ErrorDiagnostic field of the ExecutionInfo property.

      e = out.SimulationMetadata.ExecutionInfo.ErrorDiagnostic;

Data Types: char | string

Option to indicate simulation progress, specified as "off" or "on".

  • "off" — Simulations run without displaying progress messages.

  • "on" — Progress updates are displayed as simulations run.

The default value for this parameter depends on the dimensions of the first input to the sim function:

  • When the first input is a scalar Simulink.SimulationInput object, the default value is "off".

  • When the first input is an array of Simulink.SimulationInput objects, the default value is "on".

This argument is supported only when you specify the first input to the sim function as one or more Simulink.SimulationInput objects.

Example: out = sim(simin,ShowProgress="on");

Option to monitor progress using Simulation Manager, specified as "off" or "on". Consider using the Simulation Manager when you run multiple simulations using a single call to the sim function.

This argument is supported only when you specify the first input to the sim function as one or more Simulink.SimulationInput objects.

Example: out = sim(simin,ShowSimulationManager="on");

Model Syntax

expand all

Model configuration parameter value to use in simulation, specified as a name-value argument that consists of the programmatic name of the configuration parameter and the parameter value.

For example, to configure the Stop time parameter, specify the name-value argument using the name StopTime and the parameter value. These commands run a 100-second simulation of a model named MyModel.

mdl = "MyModel";
out = sim(mdl,StopTime="100");

You can use a name-value argument to specify the value for any model configuration parameter in simulations you run using the sim function. The configuration parameter values you specify are applied for the simulation and revert when the simulation ends. When you simulate a model hierarchy, the configuration parameter values you specify apply to the top model.

Specifying model configuration parameter values as name-value arguments is supported only when you specify the first input to the sim function as the name or handle of the model to simulate.

Example: out = sim("MyModel",SaveOutput="on");

Tips

  • To specify configuration parameter values on a Simulink.SimulationInput object, use the setModelParameter function.

    simin = Simulink.SimulationInput("MyModel");
simin = setModelParameter(simin,StopTime="100");

  • To get a list of model configuration parameters, use the getActiveConfigSet function and the get_param function.

    configSet = getActiveConfigSet("vdp");
configSetNames = get_param(configSet,"ObjectParameters")

    The get_param function returns a list of all the model configuration parameters, such as StopTime, SaveTime, SaveState, SaveOutput, and SignalLogging.

Option to enable fast restart for individual simulations, specified as "on" or "off". Fast restart saves time in iterative simulation workflows by skipping compilation and termination after compiling the model for the first simulation you run after enabling fast restart.

  • "on" — The simulation enables the FastRestart parameter in the model and runs using fast restart. After the simulation ends, the FastRestart parameter remains enabled in the model.

    If the model is not already initialized in fast restart, the software compiles the model before running the simulation. At the end of the simulation, the model remains initialized in fast restart. To terminate the simulation, disable fast restart. For more information, see Script Iterative or Batch Simulations Using Fast Restart.

  • "off" — The simulation disables the FastRestart parameter in the model and runs without using fast restart. The model compiles for each simulation.

    If the model is already initialized in fast restart, the sim function terminates the previous simulation before compiling the model.

By default, fast restart is disabled in models, and simulations you run using the sim function do not enable fast restart. If you do not specify this argument, the sim function uses the value of the parameter in the model.

This argument is supported only when you specify the first input to the sim function as a model name or handle.

Example: out = sim("MyModel",FastRestart="on");

Tips

  • To specify this parameter on a Simulink.SimulationInput object, use the setModelParameter function. (since R2024a)

    simin = Simulink.SimulationInput("MyModel");
simin = setModelParameter(simin,FastRestart="on");

  • To run a set of simulations using fast restart, specify the first input argument as an array of Simulink.SimulationInput objects and use the UseFastRestart name-value argument instead.

  • If you enable fast restart using the Simulink Editor or the set_param function, simulations you run using the sim function use fast restart even if you do not specify this argument.

  • Fast restart simulations return results as a single Simulink.SimulationOutput object, even if the Single simulation output configuration parameter is disabled.

Data Types: char | string

Simulation mode, specified as "normal", "accelerator", or "rapid-accelerator". If you do not specify this argument, the simulation uses the simulation mode specified in the model.

ValueDescription
"normal"

Run simulation using normal mode.

Normal mode simulations use the full model representation and provide the best support for interacting with the model during simulation.

Use normal mode for workflows that involve modifying the structure of your model between simulations. For best results, use normal mode for debugging simulations.

"accelerator"

Run simulation using accelerator mode.

Accelerator mode simulations generate an optimized representation of the model, called a simulation target, to use in simulation. The optimizations that improve the simulation performance can reduce the ability to interact with the model during simulation. Modifying the model between accelerator mode simulations can require regenerating the simulation target.

Use accelerator mode to speed up simulations in workflows that do not involve making structural changes to the model between simulations.

"rapid-accelerator"

Run simulation using rapid accelerator mode.

Rapid accelerator mode simulations generate a simulation target to use for simulation. The simulation target provides minimal support for interacting with the model during simulation. Modifying the model between rapid accelerator simulations can require rebuilding the simulation target.

Use rapid accelerator mode for the fastest simulation execution when you modify the model between simulations only by tuning variable and parameter values. Tuning certain parameter values can require rebuilding the simulation target.

For more information, see Choosing a Simulation Mode and Code Regeneration in Accelerated Models.

This argument is supported only when you specify the first input to the sim function as a model name or handle.

Example: out = sim("MyModel",SimulationMode="accelerator");

Tips

  • To specify the simulation mode on a Simulink.SimulationInput object, use the setModelParameter function.

    simin = Simulink.SimulationInput("MyModel");
simin = setModelParameter(simin,SimulationMode="accelerator");

  • Visualization blocks update during simulation when you run simulations from a UI, such as the Simulink Editor, but do not update during simulation when you run rapid accelerator simulations programmatically.

  • To prevent rebuilding the simulation target, you can disable the rapid accelerator up-to-date check by specifying the RapidAcceleratorUpToDateCheck parameter value as "off". With the up-to-date check disabled, changes you make that would require rebuilding the simulation target are ignored.

  • To simulate using rapid accelerator mode, you can specify "rapid" as a partial match for "rapid-accelerator". For more information about name-value arguments in MATLAB®, see Validate Name-Value Arguments.

Data Types: char | string

Option to capture errors and return simulation output if simulation error occurs, specified as "off" or "on".

BehaviorCaptureErrors="off" (default)CaptureErrors="on"
Issuing exceptions for simulation errors

The software issues exceptions for simulation errors.

The exception stops both the simulation in which the error occurred and the script or function that invoked the simulation, if applicable.

The software does not issue exceptions for simulation errors.

If a script or another function invoked the simulation, the error stops the simulation but does not stop the execution of the script or function.

Error reporting

Errors that occur during simulation are reported in the MATLAB Command Window.

Information about the simulation errors, including the message and the simulation phase in which the error occurred, is captured in the simulation output.

Simulation results

Issuing an exception stops the simulation immediately. The sim function does not return simulation results.

The sim function returns simulation results and metadata up to the simulation time at which the error occurred.

This argument is supported only when you specify the first input to the sim function as a model name or handle.

Example: out = sim("MyModel",CaptureErrors="on");

Tips

  • This option is not supported for software-in-the-loop (SIL) and processor-in-the-loop (PIL) simulations.

  • To specify this parameter on a Simulink.SimulationInput object, use the setModelParameter function. (since R2024a)

    simin = Simulink.SimulationInput("MyModel");
simin = setModelParameter(simin,CaptureErrors="on");

  • View information about captured errors in the simulation output and metadata.

    • The sim function captures the error in the ErrorMessage property of the Simulink.SimulationOutput object.

      msg = out.ErrorMessage;

    • To view the error message in the Diagnostic Viewer, use the sldiagviewer.reportSimulationMetadataDiagnostics function.

      sldiagviewer.reportSimulationMetadataDiagnostics(out)

    • The Simulink.SimulationMetadata object returned by the simulation contains additional information about the error, such as the simulation phase in which the error occurred. The error information is stored in the ErrorDiagnostic field of the ExecutionInfo property.

      e = out.SimulationMetadata.ExecutionInfo.ErrorDiagnostic;

Data Types: char | string

Option to start programmatic simulation debugging session, specified as "off" or "on".

This argument is supported only when you specify the first input to the sim function as a model name or handle.

Example: out = sim("MyModel",Debug="on");

Data Types: char | string

Option to disable rebuilding rapid accelerator target, specified as "on" or "off".

  • "on" — Before each simulation, the software checks whether any changes to the model require rebuilding the rapid accelerator target. If a change requires rebuilding the rapid accelerator target, the software rebuilds the target before running the simulation.

  • "off" — The software does not check whether changes to the model require rebuilding the rapid accelerator target and always runs the simulation without rebuilding the target. Changes to the model that require rebuilding the rapid accelerator target are ignored and are not reflected in the simulation.

This argument is supported only when you specify the first input to the sim function as a model name or handle.

Example: out = sim("MyModel",RapidAcceleratorUpToDateCheck="off");

Tips

To specify this option on a Simulink.SimulationInput object, use the setModelParameter function.

simin = Simulink.SimulationInput("MyModel");
simin = setModelParameter(simin,RapidAcceleratorUpToDateCheck="off");

Data Types: char | string

Maximum simulation run time, specified as a positive scalar. Specify the time, in seconds, to allow the simulation to run. If the simulation runs for longer than the value you specify, the software issues a warning and stops the simulation. For example, if you specify Timeout as 30, the software stops the simulation and issues a warning if computing simulation results takes more than 30 seconds.

The Timeout parameter specifies a limit on the amount of clock time for a simulation to run. To specify the maximum time value to simulate, use the Stop time parameter.

This argument is supported only when you specify the first input to the sim function as a model name or handle.

Example: out = sim("MyModel",Timeout=60); runs a simulation with a 60-second timeout.

Tips

  • Consider specifying a timeout when you use a variable-step solver. If simulation conditions constrain the step size, the solver starts taking very small time steps, which slows down the simulation.

  • To specify this option on a Simulink.SimulationInput object, use the setModelParameter function.

    simin = Simulink.SimulationInput("MyModel");
simin = setModelParameter(simin,Timeout=60);

Option to display summary of parameters before starting simulation, specified as "siminfo".

This argument is supported only when you specify the first input to the sim function as a model name or handle.

Example: out = sim("MyModel",Trace="siminfo");

Data Types: char | string

Output Arguments

collapse all

Simulation results and metadata, returned as a Simulink.SimulationOutput object, an array of Simulink.SimulationOutput objects, or a vector. The Simulink.SimulationOutput object contains all data logged from simulation and metadata, such as timing information and diagnostics.

To ensure sim returns results in a consistent format for any syntax, save the model with the Single simulation output configuration parameter enabled.

The sim function returns a vector of the simulation time steps if all of these conditions are met:

  • The only input argument is the name of the model.

  • The Single simulation output parameter is disabled.

  • Fast restart is disabled.

Tips

  • To return results in the same format for every syntax, save the model with the Single simulation output parameter enabled. Returning all simulation data and metadata in a single object facilitates analyzing results from multiple simulations.

  • To control execution and tune parameter values during scripted simulations, use the Simulation object. (since R2024a) For more information, see Run Simulations Programmatically.

  • To interact with simulations using both the MATLAB Command Window and the Simulink Editor, issue simulation commands using the set_param function. For more information, see Run Simulations Programmatically.

  • When you run a simulation using the sim function, the simulation runs until an error occurs or the simulation reaches the specified stop time.

  • When you simulate a model with infinite stop time, stop the simulation from the MATLAB Command Window by pressing Ctrl+C. The simulation stops, and simulation results are not saved in the MATLAB workspace.

  • Results of programmatic simulations are not available when the StopFcn model callback executes. To process simulation results, use the PostSimFcn callback of the Simulink.SimulationInput object instead.

  • Configure logging for time, states, and outputs using the Configuration Parameters dialog box. On the Modeling tab, under Setup, click Model Settings. Then, in the Configuration Parameters dialog box, select Data Import/Export.

  • To log signals throughout a model, use signal logging or logging blocks, such as the To Workspace block or the Record block. For more information, see Save Signal Data Using Signal Logging.

Version History

Introduced before R2006a

expand all

See Also

Functions

Objects

Model Settings

Topics