# pentropy

Spectral entropy of signal

## Syntax

## Description

returns the Spectral Entropy of
single-variable, single-column `se`

= pentropy(`xt`

)`timetable`

`xt`

as the `timetable`

`se`

. `pentropy`

computes the spectrogram
of `xt`

using the default options of
`pspectrum`

.

specifies additional properties using name-value arguments. Options include
instantaneous or whole-signal entropy, scaling by white noise entropy, frequency
limits, and time limits. You can use `se`

= pentropy(___,`Name=Value`

)`Name=Value`

with any of
the input arguments in previous syntaxes.

`[`

returns the spectral entropy `se`

,`t`

] = pentropy(___)`se`

along with the time vector
or `timetable`

`t`

. If `se`

is a
`timetable`

, then `t`

is equal to the
row times of `timetable`

`se`

. This syntax does not apply if
`Instantaneous`

is set to
`false`

.

`pentropy(___)`

with no output arguments plots
the spectral entropy against time. If `Instantaneous`

is set
to `false`

, the function outputs the scalar value of the
spectral entropy.

## Examples

## Input Arguments

## Output Arguments

## More About

## References

[1] Pan, Y. N., J. Chen, and X. L.
Li. "Spectral Entropy: A Complementary Index for Rolling Element Bearing Performance
Degradation Assessment." *Proceedings of the Institution of Mechanical
Engineers, Part C: Journal of Mechanical Engineering Science*. Vol. 223,
Issue 5, 2009, pp. 1223–1231.

[2] Sharma, V., and A. Parey. "A
Review of Gear Fault Diagnosis Using Various Condition Indicators." *Procedia
Engineering*. Vol. 144, 2016, pp. 253–263.

[3] Shen, J., J. Hung, and L. Lee.
"Robust Entropy-Based Endpoint Detection for Speech Recognition in Noisy Environments."
*ICSLP*. Vol. 98, November 1998.

[4] Vakkuri, A., A. Yli‐Hankala,
P. Talja, S. Mustola, H. Tolvanen‐Laakso, T. Sampson, and H. Viertiö‐Oja.
"Time‐Frequency Balanced Spectral Entropy as a Measure of Anesthetic Drug Effect in
Central Nervous System during Sevoflurane, Propofol, and Thiopental Anesthesia."
*Acta Anaesthesiologica Scandinavica*. Vol. 48, Number 2, 2004,
pp. 145–153.

## Extended Capabilities

## Version History

**Introduced in R2018a**