# wscalogram

(Not recommended) Scalogram for continuous wavelet transform

This function is no longer recommended. To obtain the scalogram, use `cwt` instead. See Version History.

## Syntax

```SC = wscalogram(TYPEPLOT,COEFS) SC = wscalogram(TYPEPLOT,COEFS,'PropName1',PropVal1,...) ```

## Description

`SC = wscalogram(TYPEPLOT,COEFS)` computes the scalogram `SC` which represents the percentage of energy for each coefficient. `COEFS` is the matrix of the continuous wavelet coefficients (see `cwt`).

The scalogram is obtained by computing:

```S = abs(coefs.*coefs); SC = 100*S./sum(S(:)) ```

When `TYPEPLOT` is equal to `'image'`, a scaled image of scalogram is displayed. When `TYPEPLOT` is equal to `'contour'`, a contour representation of scalogram is displayed. Otherwise, the scalogram is returned without plot representation.

`SC = wscalogram(TYPEPLOT,COEFS,'PropName1',PropVal1,...)` allows you to modify some properties. The valid choices for `PropName` are:

 `'scales'` Scales used for the CWT. `'ydata'` Signal used for the CWT. `'xdata'` x values corresponding to the signal values. `'power'` Positive real value. Default value is zero.

If `power > 0`, coefficients are first normalized

```coefs(k,:) = coefs(k,:)/(scales(k)^power) ```

and then the scalogram is computed as explained above.

## Examples

```% Compute signal s t = linspace(-1,1,512); s = 1-abs(t); % Plot signal s figure; plot(s), axis tight ``` ```% Compute coefficients COEFS using cwt COEFS = cwt(s,1:32,'cgau4'); % Compute and plot the scalogram (image option) figure; SC = wscalogram('image',COEFS); ``` ```% Compute and plot the scalogram (contour option) figure; SC = wscalogram('contour',COEFS); ``` ## Version History

Introduced in R2008a

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