model (Simulink Reference)

Execute a particular phase of the simulation of a model

Syntax

```
[sys,x0,str,ts] = model(t,x,u,flag);
```

Description

The model command executes a specific phase of the simulation of a Simulink model whose name is model. Use the command's flag argument to indicate the phase of the simulation to be executed. See Simulating Dynamic Systems for a description of the steps that Simulink uses to simulate a model.

This command is intended to allow linear analysis and other M-file program-based tools to run a simulation step by step, gathering information about the model's states and outputs at each step. It is not intended for interactive use, for example, to debug a model.

Use this command if you want to write an M-file program that needs to examine intermediate results of a simulation. Use the sim command if the program does not need to examine intermediate results. Use the Simulink debugger if you need to examine intermediate results to debug a model.

Arguments

sys
Vector of model size data:
sys(1) = number of continuous states

sys(2) = number of discrete states

sys(3) = number of inputs

sys(4) = number of outputs

sys(5) = reserved

sys(6) = direct-feedthrough flag (1 = yes, 0 = no)

sys(7) = number of sample times (= number of rows in ts)

x0
Vector that returns the initial condition of each of the system's states

str
State-ordering strings

ts
An m-by-2 matrix containing the sample time (period, offset) information

t
Time step

x
State vector

u
Inputs

flag
String that indicates the simulation phase to be executed:
'sizes' executes the size computation phase of the simulation. This phase determines the sizes of the model's inputs, outputs, state vector, etc.

'compile' executes the compilation phase of the simulation. The compilation phase propagates signal and sample time attributes. It is equivalent to selecting the Update Diagram (Ctrl-D) option from the Simulink Edit menu.

'update' computes the states of the model's blocks at time t.

'outputs' computes the outputs of the model's blocks at time t.

'deriv' computes the state derivatives of the model's block at time step t.

'term' causes Simulink to terminate simulation of the model.

`sys`	Vector of model size data: `sys(1)` = number of continuous states `sys(2)` = number of discrete states `sys(3)` = number of inputs `sys(4)` = number of outputs `sys(5)` = reserved `sys(6)` = direct-feedthrough flag (1 = yes, 0 = no) `sys(7)` = number of sample times (= number of rows in `ts`)
`x0`	Vector that returns the initial condition of each of the system's states
`str`	State-ordering strings
`ts`	An `m`-by-`2` matrix containing the sample time (period, offset) information
`t`	Time step
`x`	State vector
`u`	Inputs
`flag`	String that indicates the simulation phase to be executed: `'sizes'` executes the size computation phase of the simulation. This phase determines the sizes of the model's inputs, outputs, state vector, etc. `'compile'` executes the compilation phase of the simulation. The compilation phase propagates signal and sample time attributes. It is equivalent to selecting the Update Diagram (Ctrl-D) option from the Simulink Edit menu. `'update'` computes the states of the model's blocks at time `t`. `'outputs'` computes the outputs of the model's blocks at time `t`. `'deriv'` computes the state derivatives of the model's block at time step `t`. `'term'` causes Simulink to terminate simulation of the model.

Examples

This command executes the compilation phase of the vdp model that comes with Simulink.

```
vdp([], [], [], 'compile')
```

The following command terminates the simulation initiated in the previous example.

```
vdp([], [], [], 'term')
```

Note You must always terminate simulation of the model by invoking the model command with the 'term' command. Simulink does not let you close the model until you have terminated the simulation.

See Also

sim

Simulation Commands sim