MATLAB: Hi,i am trying to run the following program,but it shows index out of bounds .length of the signal loaded is=10240 and when i am taking square for x ,it shows index out of bounds error and also one more error is undefined function chebyshev

average shannon erengy

function segmentation_Shennon
 close all 
 clear all 
  % Load the data file
 [F, Fs] = audioread ('1.wav'); 
  pcg = F (:, 2); 
 t = 0: 1 / Fs: (length (F) -1) / Fs; 
 %%We normalize and filter the signal with a Chebyshev filter of 1 8th order NP with a frequency of medium 882 Hz 
 pcg_filter = chebushev1 (pcg, Fs);
 pcg_norm = pcg_filter./abs(max(pcg_filter));
 % calculate the energy of Shannon
 shennon_energy = - ((pcg_norm. ^ 2). * log (pcg_norm. ^ 2));
 figure (1)
 plot (t, shennon_energy)
  % calculate the average Shannon energy in a segment lasting 0.02 s
 % with an overlap of 0.01 s
 win = 0.002 * Fs; 
 i = 1;
 k = 1;
 Es = [];
 Es_t = [];
 P = [];
  while i <length (pcg_norm)
  for i = i: i + win
 square = pcg_norm (i). ^ 2; 
 Es (k) = -1 / win * sum (square. * Log (square));
 end
 ES_t (k) = t (i); 
 i = i + round (win / 2);
 k = k + 1;
 end
  % we normalize Shannon's averaged energy
 M_Es = (mean (Es));  % mean energy of the segment
 S_Es = (std (Es (k-1)));  % standard deviation of the energy of the segment
 P (k) = (Es (k-1) -M_Es) / S_Es;  % Shannon's normalized averaged energy,
 plot (t, P)

Best Answer

You appear to have a typing mistake: you used chebushev1 but the English version of the name is chebyshev . However there is no chebyshev1 function: there is cheby1 https://www.mathworks.com/help/signal/ref/cheb1ord.html and there is the MuPAD orthopoly:chebyshev1 which is not likely what you are wanting to call.
With respect to the out of range: you have
    pcg = F (:, 2);
which assumes that F has two or more columns, which would correspond to two or more channels. If your '1.wav' is mono then it would only have one column, F(:,1);
Related Question