# spectralSpread

## Syntax

## Description

specifies options using one or more name-value arguments.`spread`

= spectralSpread(`x`

,`f`

,`Name=Value`

)

`spectralSpread(___)`

with no output arguments plots the
spectral spread.

If the input is in the time domain, the spectral spread is plotted against time.

If the input is in the frequency domain, the spectral spread is plotted against frame number.

## Examples

## Input Arguments

## Output Arguments

## Algorithms

The spectral spread is calculated as described in [1]:

$$\text{spread}=\sqrt{\frac{{\displaystyle \sum _{k={b}_{1}}^{{b}_{2}}{\left({f}_{k}-{\mu}_{1}\right)}^{2}{s}_{k}}}{{\displaystyle \sum _{k={b}_{1}}^{{b}_{2}}{s}_{k}}}}$$

where

*f*is the frequency in Hz corresponding to bin_{k}*k*.*s*is the spectral value at bin_{k}*k*.*b*_{1}and*b*_{2}are the band edges, in bins, over which to calculate the spectral spread.*μ*_{1}is the spectral centroid, calculated as described by the`spectralCentroid`

function.

## References

[1] Peeters, G. "A Large Set of Audio Features for Sound Description (Similarity and Classification) in the CUIDADO Project." Technical Report; IRCAM: Paris, France, 2004.

## Extended Capabilities

## Version History

**Introduced in R2019a**