# linmodv5

Extract continuous-time linear state-space model around operating point using full model perturbation algorithm

## Syntax

## Description

computes the linear state-space model of the system of ordinary differential equations
represented by the model `[A,B,C,D]`

= linmodv5(`mdl`

)`mdl`

using the perturbation algorithm from
versions 5.3 and earlier. Inport and Outport blocks in the
model represent the system inputs and outputs.

**Note**

`linmodv5`

provides only basic linearization functionality. For
full linearization functionality, use Simulink^{®}
Control Design™ software. For more information, see Choose Linearization Tools (Simulink Control Design).

returns the
linearized model in transfer function form.`[n,d]`

= linmodv5(___)

returns a
structure that contains the linearized model, state names, input and output names, and
information about the operating point.`sys`

= linmodv5(___)

## Input Arguments

## Limitations

`linmodv5`

provides only basic linearization functionality. For full linearization functionality, use Simulink Control Design software. For more information, see Choose Linearization Tools (Simulink Control Design).Linearization is not supported for models that contain one or more referenced models configured to use a local solver. For more information, see Use Local Solvers in Referenced Models.

## Tips

By default, the system time is zero. For systems that are dependent on time, you can specify the system time using the second element of the

`opts`

input argument.State order is maintained in linearization such that the order of states in the linearized model matches the order of states in the nonlinear model. You can get information about the states in a model and the blocks associated with the states by using the model name as a programmatic interface to execute the sizes phase. The return argument named

`blks`

is a vector that contains the name of each block associated with a state. For more information, see Use Model Name as Programmatic Interface.`[sys,x0,blks,st] = modelName([],[],[],'sizes');`

You can convert the state-space linearized representation of a linearized single-input, multiple-output system to another form using these functions:

You can create a state-space model object from a linearized model using the

`ss`

(Control System Toolbox) function. You can use state-space model objects to represent a linear time invariant (LTI) system for control design. You can also combine multiple LTI state-space models to represent more complex systems.After creating a state-space model object, you can convert to transfer function form using the

`tf`

(Control System Toolbox) function or convert to zero-pole-gain form using the`zpk`

(Control System Toolbox) function.The default block-by-block algorithm of the

`linmod`

function is recommended for linearizing models that contain Transport Delay or Derivative blocks. The block-by-block algorithm replaces Transport Delay and Derivative blocks with Pade approximations. Using the`v5`

perturbation algorithm to linearize models that contain Transport Delay or Derivative blocks can be troublesome. For more information, see Linearizing Models.Before linearizing a model that contains Transport Delay or Derivative blocks using the

`v5`

perturbation algorithm, replace the Transport Delay and Derivative blocks with the specialized blocks available in the Linearization library inside the Simulink Extras library.

## Version History

**Introduced in R2011b**