wenergy

Energy for 1-D wavelet or wavelet packet decomposition

Description

example

[Ea,Ed] = wenergy(c,l) returns, for a 1-D wavelet decomposition, Ea, the percentage of energy corresponding to the approximation, and Ed, the percentages of energies corresponding to the details. c and l are outputs of wavedec.

E = wenergy(wpt) returns the percentages of energy corresponding to the terminal nodes of the wavelet packet tree wpt (see wptree, wpdec, and wpdec2). In this case, wenergy is a method of the wptree object wpt, which overloads the previous wenergy function.

Examples

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Obtain the 4-level wavelet decomposition of the signal using the sym4 wavelet.

wv = "sym4";
[c,l] = wavedec(noisbump,4,wv);

Obtain the percentages of energy in the approximation and details coefficients.

[Ea,Ed] = wenergy(c,l)
Ea = 88.2860

Ed = 1×4

2.1560    1.2286    1.4664    6.8630

Obtain the wavelet packet tree corresponding to the 3-level wavelet packet decomposition of the signal using the sym4 wavelet.

t = wpdec(noisbump,3,wv);

Obtain the percentages of energy in the terminal nodes.

e = wenergy(t)
e = 1×8

95.0329    1.4664    0.6100    0.6408    0.5935    0.5445    0.5154    0.5965

Input Arguments

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Wavelet decomposition, specified as a vector. The vector contains the wavelet coefficients. The bookkeeping vector l contains the number of coefficients by level. See wavedec.

Data Types: single | double
Complex Number Support: Yes

Bookkeeping vector, specified as a vector of positive integers. The bookkeeping vector is used to parse the coefficients in the wavelet decomposition c by level. See wavedec.

Data Types: single | double

Wavelet packet tree, specified as a wptree object. See wptree, wpdec, and wpdec2.

Output Arguments

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Percentage of energy corresponding to approximation coefficients, returned as a positive scalar.

Data Types: single | double

Percentage of energy corresponding to details coefficients, returned as a vector.

Data Types: single | double

Percentage of energy corresponding to the terminal nodes, returned as a vector.

Data Types: single | double 