m working on feature extraction through mfcc as i need coefficients,but facing some errors, how to resolve these? please tell me ASAP. I'll be very thank ful to you.pankha1 is my wave file name and error is coming in while loop, &in nx = nx./ max(nx)

    if true
    fs = 10000;% Sampling Frequency
t = hamming(4000);% Hamming window to smooth the speech signal
w = [t ; zeros(6000,1)];
f = (1:10000);
mel(f) = 2595 * log(1 + f / 700);% Linear to Mel frequency scale conversion
tri = triang(100);
win1 = [tri ; zeros(9900,1)];% Defining overlapping triangular windows for 
win2 = [zeros(50,1) ; tri ; zeros(9850,1)];% frequency domain analysis 
win3 = [zeros(100,1) ; tri ; zeros(9800,1)];
win4 = [zeros(150,1) ; tri ; zeros(9750,1)];
win5 = [zeros(200,1) ; tri ; zeros(9700,1)];
win6 = [zeros(250,1) ; tri ; zeros(9650,1)];
win7 = [zeros(300,1) ; tri ; zeros(9600,1)];
win8 = [zeros(350,1) ; tri ; zeros(9550,1)];
win9 = [zeros(400,1) ; tri ; zeros(9500,1)];
win10 = [zeros(450,1) ; tri ; zeros(9450,1)];
win11 = [zeros(500,1) ; tri ; zeros(9400,1)];
win12 = [zeros(550,1) ; tri ; zeros(9350,1)];
win13 = [zeros(600,1) ; tri ; zeros(9300,1)];
win14 = [zeros(650,1) ; tri ; zeros(9250,1)];
win15 = [zeros(700,1) ; tri ; zeros(9200,1)];
win16 = [zeros(750,1) ; tri ; zeros(9150,1)];
win17 = [zeros(800,1) ; tri ; zeros(9100,1)];
win18 = [zeros(850,1) ; tri ; zeros(9050,1)];
win19 = [zeros(900,1) ; tri ; zeros(9000,1)];
win20 = [zeros(950,1) ; tri ; zeros(8950,1)];
x = wavread('pankha1.wav');
%x = wavrecord(1 * fs, fs,'double');% Record and store the uttered speech
plot(x);
wavplay(x);
i = 1;
while abs(x(i)) < 0.05   % Silence detection 
i = i + 1;
end
x(1 : i) = [];
x(6000 : 10000) = 0;
x1 = x.* w;
mx = fft(x1);% Transform to frequency domain
nx = abs(mx(floor(mel(f))));% Mel warping
nx = nx./ max(nx);
nx1 = nx.* win1;
nx2 = nx.* win2;
nx3 = nx.* win3;
nx4 = nx.* win4;
nx5 = nx.* win5;
nx6 = nx.* win6;
nx7 = nx.* win7;
nx8 = nx.* win8;
nx9 = nx.* win9;
nx10 = nx.* win10;
nx11 = nx.* win11;
nx12 = nx.* win12;
nx13 = nx.* win13;
nx14 = nx.* win14;
nx15 = nx.* win15;
nx16 = nx.* win16;
nx17 = nx.* win17;
nx18 = nx.* win18;
nx19 = nx.* win19;
nx20 = nx.* win20;
sx1 = sum(nx1.^ 2);% Determine the energy of the signal within each window
sx2 = sum(nx2.^ 2);% by summing square of the magnitude of the spectrum 
sx3 = sum(nx3.^ 2);
sx4 = sum(nx4.^ 2);
sx5 = sum(nx5.^ 2);
sx6 = sum(nx6.^ 2);
sx7 = sum(nx7.^ 2);
sx8 = sum(nx8.^ 2);
sx9 = sum(nx9.^ 2);
sx10 = sum(nx10.^ 2);
sx11 = sum(nx11.^ 2);
sx12 = sum(nx12.^ 2);
sx13 = sum(nx13.^ 2);
sx14 = sum(nx14.^ 2);
sx15 = sum(nx15.^ 2);
sx16 = sum(nx16.^ 2);
sx17 = sum(nx17.^ 2);
sx18 = sum(nx18.^ 2);
sx19 = sum(nx19.^ 2);
sx20 = sum(nx20.^ 2);
sx = [sx1, sx2, sx3, sx4, sx5, sx6, sx7, sx8, sx9, sx10, sx11, sx12, sx13, sx14, sx15, sx16, sx17,sx18, sx19, sx20];
sx = log(sx);
dx = dct(sx);% Determine DCT of Log of the spectrum energies 
fid = fopen('sample.dat','w');
fwrite(fid, dx,'real*8');% Store this feature vector as a .dat file
fclose(fid); 
  end