Scalogram for continuous wavelet transform
SC = wscalogram(TYPEPLOT,COEFS)
SC = wscalogram(TYPEPLOT,COEFS,'PropName1',PropVal1,...)
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.
|'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.
% 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);