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Extract descriptor state-space data


[A,B,C,D,E] = dssdata(sys)
[A,B,C,D,E,Ts] = dssdata(sys)


[A,B,C,D,E] = dssdata(sys) returns the values of the A, B, C, D, and E matrices for the descriptor state-space model sys (see dss). dssdata equals ssdata for regular state-space models (i.e., when E=I).

If sys has internal delays, A, B, C, D are obtained by first setting all internal delays to zero (creating a zero-order Padé approximation). For some systems, setting delays to zero creates singular algebraic loops, which result in either improper or ill-defined, zero-delay approximations. For these systems, dssdata cannot display the matrices and returns an error. This error does not imply a problem with the model sys itself.

[A,B,C,D,E,Ts] = dssdata(sys) also returns the sample time Ts.

You can access other properties of sys using get or direct structure-like referencing (e.g., sys.Ts).

For arrays of SS models with variable order, use the syntax

[A,B,C,D,E] = dssdata(sys,'cell')

to extract the state-space matrices of each model as separate cells in the cell arrays A, B, C, D, and E.

Version History

Introduced before R2006a

See Also

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