## Contents

## FCMODOM

Estimates the *A* and *C* matrix in a discrete-time state-space model from frequency response function (FRF) data that was preprocessed by `fdordom`.

## Syntax

`[A,C] = fdmodom(R,n)`

## Description

This function estimates the *A* and *C* matrices corresponding to an *n* th order discrete-time LTI state-space model. The compressed data matrix *R* from the preprocessor function `fdordom` is used to this end.

## Inputs

`R` is a compressed data matrix containing information about the measured data, as well as information regarding the system dimensions.

`n` is the desired model order *n*.

## Outputs

`A` is the state-space model's *A* matrix.

`C` is the state-space model's *C* matrix.

## Algorithm

The data matrix obtained with `fcordom` contains the weighted left singular vectors of a matrix similar to the `R22` matrix (see `fdordom`). The first *n* of these vectors form an estimate *Os* of the system's extended observability matrix:

The estimates Ahat and Chat are obtained by linear regression:

## Used By

This a top-level function that is used directly by the user.