entropy of a signal

Hello every body . Please give me command for entropy calculation of a signal. How we can calculate using wentropy function in wavelet? Thanks in advance .

[divya pawar]

The entropy function given in Matlab is for image processing, so for other signals simply the formula

entropy= -sum(p*log2(p));

If probabilities are not known , you can use histogram to find them

h1=histogram(your_signal, 'Normalization', 'Probability');

h1.Values;

[mamta p]

thank you Divya Pawar mam.

Answer 1

[maria]

Hi! For find the value of entropy for a signal 1-dimensional, can use:

p = hist(signal length);

entropy = -sum(p.*log2(p));

Do this solve your question?

Answer 2

[dany katamba mpoyi]

I = randn(10000000,1);

p = hist(I,1000000);

% remove zero entries in p

p(p==0) = [];

% normalize p so that sum(p) is one.

p = p ./ numel(I);

Eg = -sum(p.*log(p));

I = randn(10000000,1);

p = hist(I,1000000);

% remove zero entries in p

p(p==0) = [];

% normalize p so that sum(p) is one.

p = p ./ numel(I);

Et = -sum(p.*log(p));

negE=Et-Eg