# centerPeriods

CWT filter bank bandpass center periods

## Syntax

``p = centerPeriods(fb)``

## Description

example

````p = centerPeriods(fb)` returns the wavelet bandpass center periods `p` for the continuous wavelet transform (CWT) filter bank `fb`.```

## Examples

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Create two CWT filter banks. Set the sampling period of the first filter bank to 0.5 seconds, and the sampling frequency of the second filter bank to 2 Hz.

```fb = cwtfilterbank('SamplingPeriod',seconds(0.5)); fb2 = cwtfilterbank('SamplingFrequency',2);```

Obtain the bandpass center periods of both filter banks. Confirm the center periods of both filter banks are equal.

```bp = centerPeriods(fb); bp2 = centerPeriods(fb2); bp(1:5)```
```ans = 5x1 duration 1.1517 sec 1.2344 sec 1.323 sec 1.418 sec 1.5197 sec ```
`bp2(1:5)`
```ans = 5×1 1.1517 1.2344 1.3230 1.4180 1.5197 ```

Obtain the bandpass center frequencies of the second filter bank. Confirm the reciprocals of the center frequencies are equal to the center periods.

```f2 = centerFrequencies(fb2); 1./f2(1:5)```
```ans = 5×1 1.1517 1.2344 1.3230 1.4180 1.5197 ```

## Input Arguments

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Continuous wavelet transform (CWT) filter bank, specified as a `cwtfilterbank` object.

## Output Arguments

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Wavelet bandpass center periods, returned as a real-valued vector of length Ns, where Ns is the number of scales in the filter bank.

If `SamplingPeriod` is specified, `p` is a duration array with the same units and format as `SamplingPeriod`. If `SamplingFrequency` is specified, `p` is in seconds. 