Documentation

Simulate the vdp model with parameter values specified as consecutive name-value pairs.

simOut = sim('vdp','SimulationMode','normal','AbsTol','1e-5',...
            'SaveState','on','StateSaveName','xout',...
            'SaveOutput','on','OutputSaveName','yout',...
 'SaveFormat', 'Dataset');
outputs = simOut.get('yout')

outputs = 

  Simulink.SimulationData.Dataset
  Package: Simulink.SimulationData

  Characteristics:
              Name: 'yout'
    Total Elements: 2

  Elements:
    1 : 'x1'
    2 : 'x2'

  -Use get or getElement to access elements by index or name.
  -Use addElement or setElement to add or modify elements.

You simulate the model in Normal mode, specifying an absolute tolerance for solver error. The sim function returns SimOut, a single Simulink.SimulationOutput object that contains all of the simulation outputs (logged time, states, and signals). The sim function does not return simulation values to the workspace.

Plot the output signal values against time.

x1=(outputs.get('x1').Values);
x2=(outputs.get('x2').Values);
plot(x1); hold on;
plot(x2);
title('VDP States')
xlabel('Time'); legend('x1','x2')

Example syntax and resulting output for capturing errors with sim is:

simOut = sim('my_model', 'CaptureErrors', 'on');
simOut.getSimulationMetadata.ExecutionInfo

ans = 

  struct with fields:

               StopEvent: 'DiagnosticError'
         StopEventSource: []
    StopEventDescription: 'Division by zero in 'my_model/Divide''
         ErrorDiagnostic: [1×1 struct]
      WarningDiagnostics: [0×1 struct]

Another advantage of this approach is that the simulation error does not also cause sim to stop. Therefore, if you are using sim in a for loop for example, subsequent iterations of the loop will still run.

This example simulates the model with parameter values specifies as name-value pairs. Run the simulation.

simOut = sim('vdp','SimulationMode','normal','AbsTol','1e-5',...
            'SaveState','on','StateSaveName','xoutNew',...
            'SaveOutput','on','OutputSaveName','youtNew',...
 'SaveFormat', 'StructureWithTime');

Access the ModelInfo property, which has some basic information about the model and solver.

simOut.getSimulationMetadata.ModelInfo

ans = 

  struct with fields:

                  ModelName: 'vdp'
               ModelVersion: '1.6'
              ModelFilePath: 'C:\MyWork'
                     UserID: 'User'
                MachineName: 'MyMachine'
                   Platform: 'PCWIN64'
    ModelStructuralChecksum: [4×1 uint32]
             SimulationMode: 'normal'
                  StartTime: 0
                   StopTime: 20
                 SolverInfo: [1×1 struct]
            SimulinkVersion: [1×1 struct]
                LoggingInfo: [1×1 struct]

Inspect the solver information.

simOut.getSimulationMetadata.ModelInfo.SolverInfo

ans = 

  struct with fields:

           Type: 'Variable-Step'
         Solver: 'ode45'
    MaxStepSize: 0.4000

Review timing information for your simulation, such as when your simulation started and finished, and the time the simulation took to initialize, execute, and terminate.

simOut.getSimulationMetadata.TimingInfo

ans = 

  struct with fields:

          WallClockTimestampStart: '2016-06-17 10:26:58.433686'
           WallClockTimestampStop: '2016-06-17 10:26:58.620687'
    InitializationElapsedWallTime: 0.1830
         ExecutionElapsedWallTime: 1.0000e-03
       TerminationElapsedWallTime: 0.0030
             TotalElapsedWallTime: 0.1870

Add notes to your simulation.

simOut=simOut.setUserString('Results from simulation 1 of 10');
simOut.getSimulationMetadata

ans = 

  SimulationMetadata with properties:

        ModelInfo: [1×1 struct]
       TimingInfo: [1×1 struct]
    ExecutionInfo: [1×1 struct]
       UserString: 'Results from simulation 1 of 10'
         UserData: []

You can also add your own custom data using the UserData property.

Start a simulation.

set_param('vdp','SimulationCommand','start')

When you start a simulation using set_param and the 'start' argument, you must use the 'stop' argument to stop it.

Pause, continue, and stop a simulation.

set_param('vdp','SimulationCommand','pause')
set_param('vdp','SimulationCommand','continue')
set_param('vdp','SimulationCommand','stop')

When you use set_param to pause or stop a simulation, the commands are requests for such actions and the simulation doesn’t execute them immediately. You can use set_param to start a simulation after the stop command and to continue a simulation after the pause command. Simulink^® first completes uninterruptable work, such as solver steps and other commands that preceded the set_param command. Then, simulation starts, pauses, continues or stops as specified by the set_param command.

Check the status of a simulation.

get_param('vdp','SimulationStatus')

The software returns 'stopped', 'initializing', 'running', 'paused', 'compiled', 'updating', 'terminating', or 'external' (used with the Simulink Coder™ product).

To update the changed workspace variables dynamically while a simulation is running, use the update command.

set_param('vdp','SimulationCommand','update')

Write all data-logging variables to the base workspace.

set_param('vdp','SimulationCommand','WriteDataLogs')

Write a MATLAB script that finds Scope blocks in your model and opens them in the foreground when you simulate the model. Save the script in the current folder.

% openscopes.m 
% Brings scopes to forefront at beginning of simulation.

blocks = find_system(bdroot,'BlockType','Scope');

% Finds all of the scope blocks in the top level of your
	% model. To find scopes in subsystems, provide the subsystem
	% names. Type help find_system for more on this command.

for i = 1:length(blocks)
  set_param(blocks{i},'Open','on')
end

% Loops through all of the scope blocks and brings them
	% to the forefront.

Set the StartFcn parameter for the model to call the openscopes script.

set_param('my_model','StartFcn','openscopes')