Visualize scattering or scalogram coefficients
scattergram(___) with no output arguments plots the
scattergram in the current figure. You can use any of the input syntaxes shown
Load an ECG signal sampled at 180 Hz. Create a scattering decomposition framework that can be used with the signal.
load wecg Fs = 180; sf = waveletScattering('SignalLength',numel(wecg),... 'SamplingFrequency',Fs);
Calculate the scattering transform of the signal.
[S,U] = scatteringTransform(sf,wecg);
Visualize the scattergram for the first-order scattering and scalogram coefficients.
sf— Scattering decomposition framework
Scattering decomposition framework, specified as a
comma-separated pairs of
the argument name and
Value is the corresponding value.
Name must appear inside quotes. You can specify several name and value
pair arguments in any order as
'FilterBank',1specifies the first filter bank.
'FilterBank'— Filter bank index
Filter bank index, specified as a positive number between 1 and the number of
filter banks in
returns the scattergram for the specified filter bank in
number of filter banks in
sf is equal to the number of specified
FilterBank is greater than 1,
scattergram averages the scalogram or scattering coefficients
over all paths terminating at each wavelet bandpass filter. To obtain paths with a
common parent, use the
'Parent' name-value pair.
'P'— Path parent index
Path parent index, specified as a nonnegative integer. The scalar
P is a nonnegative integer representing the
P-th wavelet filter at the filter bank
FilterBank − 1.
scattergram returns the
scattergram for the path at the specified filter bank with parent
FilterBank is equal to 1, the zeroth
filter bank corresponds to the input signal in the case of the scalogram coefficients
and the lowpass filtering of the input signal with the scaling function in the case of
the scattering coefficients. Lower values of
P correspond to
wavelets with higher bandpass frequencies.
If you specify
P, you must specify the
FilterBank name-value pair.
If you specify a value for
P which results in a single child,
img is a vector. The scattergram of a single child is
a line plot. If you specify a value for
P that results in no
scattergram returns the scattergram for the filter bank
Scattergram, returned as a real-valued matrix or vector. If you use the
Parent name-value pair and specify a value which results in a
img is a vector. If the parent has more than one
img is a matrix.