# rncf

## Description

computes
the right normalized coprime factorization of the dynamic system model
`fact`

= rncf(`sys`

)`sys`

. The factorization is given by:

$$sys={N}_{r}{M}_{r}^{-1},\text{\hspace{1em}}{M}_{r}^{*}{M}_{r}+{N}_{r}^{*}{N}_{r}=I.$$

Here, $${M}_{r}^{*}$$ denotes the conjugate of *M _{r}* (see

`ctranspose`

).
The returned model `fact`

is a minimal state-space realization of the
stable system
[*M*;

_{r}*N*]. This factorization is used in other normalized coprime factor computations such as model reduction (

_{r}`reducespec`

)
and controller synthesis (`ncfsyn`

).## Examples

## Input Arguments

## Output Arguments

## Tips

`fact`

is a minimal realization of`[Mr;Nr]`

. If you need to use`[Mr;Nr]`

or`[Mr;Nr]'`

in a computation, it is better to use`fact`

than to concatenate the factors yourself. Such manual concatenation results in extra (nonminimal) states, which can lead to decreased numerical accuracy.

## Version History

**Introduced in R2019a**

## See Also

`lncf`

| `reducespec`

| `ncfsyn`