arma2ss transform an armax data structure into state space representation.

## Syntax

                [S, Sn] = arma2ss(Ar)
                S = arma2ss(Ar)

## Parameters

Ar

  an armax data structure (see armac.

S

  a discrete time state space data structure (see syslin. The regular input to output transfer.

Sn

  a discrete time state space data structure (see syslin. The noise input to output transfer.

## Description

`[S,Sn] = arma2ss(Ar)` transform an armax data structure into a state space representation. The full armax transfer `F`can be obtained by `F=[S,Sn]`.

## Examples

    A = [eye(2,2),[-1.5 0.1;-0.2 1.5],[0.7 -0.3;0.1 0.7]];
                B = [[0;0] [1;-1] [0.5;1.2]];
                Ar = armac(A, B, zeros(2, 2), 2, 1, 0)
                [S, Sn] = arma2ss(Ar)

## See also

- armac
- arma
- syslin

## History

5.4.0 arma2ss added.