Cross-correlation

`r = xcorr(x,y)`

`r = xcorr(x)`

`r = xcorr(___,maxlag)`

`r = xcorr(___,scaleopt)`

```
[r,lags]
= xcorr(___)
```

returns the cross-correlation
of two discrete-time sequences. Cross-correlation measures the similarity between a vector
`r`

= xcorr(`x`

,`y`

)`x`

and shifted (lagged) copies of a vector `y`

as
a function of the lag. If `x`

and `y`

have different
lengths, the function appends zeros to the end of the shorter vector so it has the same
length as the other.

`r = xcorr(___,`

limits the
lag range from `maxlag`

)`-maxlag`

to `maxlag`

for either of
the previous syntaxes.

[1] Buck, John R., Michael M. Daniel,
and Andrew C. Singer. *Computer Explorations in Signals and Systems Using
MATLAB ^{®}*. 2nd Edition. Upper Saddle River, NJ: Prentice Hall,
2002.

[2] Stoica, Petre, and Randolph Moses.
*Spectral Analysis of Signals*. Upper Saddle River, NJ: Prentice Hall,
2005.