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resume

Continue paused simulation represented by Simulation object

Since R2024a

    Syntax

    Description

    example

    resume(s) continues the paused simulation represented by the Simulation object s.

    To advance the simulation by a specified amount, use the step function.

    Examples

    collapse all

    Open the model vdp.

    mdl = "vdp";
    open_system(mdl)

    The model vdp.

    Create a Simulation object to represent a simulation of the model.

    sm = simulation(mdl);

    The model vdp is small and simple and simulates very fast. Configure the simulation to run at a slower pace relative to real or wall clock time so the simulation runs long enough for you to interact with it. This code configures the simulation to run at a rate of approximately two simulation seconds per one second of real time.

    sm = setModelParameter(sm,EnablePacing="on");
    sm = setModelParameter(sm,PacingRate="2");

    Configure the simulation to run to a stop time of 40 seconds.

    sm = setModelParameter(sm,StopTime="40");

    Check the simulation status by using the Status property. Before you start or initialize the simulation, the simulation status is inactive.

    sm.Status
    ans = 
    "inactive"
    

    You can initialize the simulation without starting it. Initializing the simulation compiles the model and sets up resources, such as memory, for running the simulation. After you initialize the simulation, the simulation status is initialized. The Simulink® Editor locks to prevent modifications to the model or simulation by anything other than the Simulation object that controls the simulation.

    initialize(sm)
    sm.Status
    ans = 
    "initialized"
    

    Start the simulation and check the simulation status. Then, after a few seconds, pause the simulation and check the status. This code uses the MATLAB® pause function to pause the execution of the script and allow the simulation to run for five seconds before executing the call to the pause function for the Simulation object, which pauses the simulation.

    start(sm)
    sm.Status
    ans = 
    "running"
    
    pause(5) % pause script execution
    pause(sm) % pause simulation
    sm.Status
    ans = 
    "paused"
    

    The plot in the Scope block updates during the simulation. Logged data also streams to the Simulation Data Inspector.

    The plot in the Scope block shows the values computed for the signals named x1 and x2 in the first 10 seconds of the simulation. The status bar in the Scope window indicates that the simulation is paused at a simulation time of approximately 10 seconds.

    Check the simulation time. While the script was paused for five seconds, the simulation advanced to a simulation time of approximately 10 seconds. The simulation is not exactly 10 because:

    • The pacing rate of two simulation seconds per second of real time is approximate.

    • The variable-step solver determines the major time hits in the simulation.

    sm.Time
    ans = 10.0521
    

    Use the pause function to pause a running simulation on demand. To pause the simulation at or after a specific simulation time, use the step function with the PauseTime argument.

    For example, advance the simulation through a simulation time of 25 seconds.

    step(sm,PauseTime=25);

    Check the simulation time. The simulation pauses at the top of the first major time hit with a simulation time greater than or equal to the specified pause time.

    sm.Time
    ans = 25.4339
    

    Because the simulation pauses at the top of the major time hit, output values are not available for the current simulation time. Check the time of the last value in the simulation outputs.

    sm.SimulationOutput.yout{1}.Values.Time(end)
    ans = 24.8081
    

    The status bar in the Scope window and the status bar in the Simulink® Editor both indicate the time of the last output calculation.

    The plot in the Scope block shows the values computed for the signals named x1 and x2 through a simulation time of approximately 25 seconds.

    In the Simulink Editor, the asterisk next to the time indicates that the current simulation time is ahead of the time the status bar reports.

    The status bar shows that the simulation time T is 24.808 with an asterisk. Next to the simulation time, the progress bar shows the simulation progress and indicates that the simulation is currently paused.

    Advance the simulation through the current major time hit.

    step(sm);

    The output results are now available for the time step.

    sm.SimulationOutput.yout{1}.Values.Time(end)
    ans = 25.4339
    

    To continue the simulation, use the resume function.

    resume(sm)

    To stop the simulation before the simulation completes, use the stop function. This code uses the MATLAB pause function to pause the execution of the script so that the simulation can run for some time before the script executes the stop command.

    pause(5)
    out = stop(sm)
    out = 
      Simulink.SimulationOutput:
                       tout: [97x1 double] 
                       yout: [1x1 Simulink.SimulationData.Dataset] 
    
         SimulationMetadata: [1x1 Simulink.SimulationMetadata] 
               ErrorMessage: [0x0 char] 
    
    

    Check the simulation status. Because the simulation did not enable fast restart, stopping the simulation also terminates the simulation. After stopping, the simulation status is inactive.

    sm.Status
    ans = 
    "inactive"
    

    The stop function returns the Simulink.SimulationOutput object that contains the simulation results. You can also access the results from the SimulationOutput property of the Simulation object.

    outprop = sm.SimulationOutput
    outprop = 
      Simulink.SimulationOutput:
                       tout: [97x1 double] 
                       yout: [1x1 Simulink.SimulationData.Dataset] 
    
         SimulationMetadata: [1x1 Simulink.SimulationMetadata] 
               ErrorMessage: [0x0 char] 
    
    

    When you run another simulation using the Simulation object sm, the results from the current simulation ovrewrite the SimulationOutput property.

    Input Arguments

    collapse all

    Simulation to continue, specified as a Simulation object.

    Version History

    Introduced in R2024a