nkshift (System Identification Toolbox)

System Identification Toolbox

nkshift

Shift data sequences.

Syntax

```
Datas = nkshift(Data,nk)
```

Description

Data contains input-output data in the iddata format.

nk is a row vector with the same length as the number of input channels in Data.

Datas is an iddata object where the input channels in Data have been shifted according to nk. A positive value of nk(ku) means that input channel number ku is delayed nk(ku) samples.

nkshift lives in symbiosis with the InputDelay property of idmodel

```
    m1 = pem(dat,4,'InputDelay',nk) 
```

is related to

```
    m2 = pem(nkshift(dat,nk),4);
```

such that m1 and m2 are the same models, but m1 stores the delay information for use when frequency responses etc. are computed.

Note the difference with the idss and idpoly property nk

```
m3 = pem(dat,4,'nk',nk) 
```

gives a model which itself explicitly contains a delay of nk samples.

See Also

idss, Algorithm Properties

misdata noisecnv