unexpected output from a for loop in matlab - matlab

Question

am trying to execute the following code on matlab i've a for loop inside a function and it's supposed to store a result at every iteration ,, but when it executes it just gives me the result of the last iteration,, is there something wrong with the sequence of the code ?
the inpit data1 is a data vector of size (33167*1)
i doubt that there is sometnig wrong with the foor loop.. there is the code i wrote :
function [vectorDominant] = processData(data1 , samplingRate , startRange, endRange)
%(length(data)/1000)
data = data1;
windowSize = 10;
samplingRate = samplingRate;
frame_len = samplingRate*windowSize;
l = length(data);
num_frames = floor(l/frame_len);
t = 1;
for i = 1 : num_frames
frame = data( (i-1)*frame_len+1 : frame_len*i);
% --- haming window ------
hammingData=frame.*hamming(length(frame));
%---- remove dc offset from data ----
dataWindowed = detrend(hammingData);
% ---- apply fft ----
fourierTransform_data=fft(dataWindowed);
y = fourierTransform_data ;
%plot(abs(fourierTransform_data))
%------- find dominant-----
len = (length(frame)/2) -1;
y = y(1:len);
[v,k] = max(y);
fftLength = length(frame);
freq = (0:(samplingRate/fftLength) :(samplingRate/2));
%plot(freq,abs(y)), grid('on'), title('dominant freq')
freq = freq(find(freq>=startRange & freq<=endRange));
dominantFrequency = freq(k);
%array[(length(data)/1000)];
%var = 1;
%while var<= length(num_frames)
n = (length(data)/1000);
vectorDominant = zeros(n,1); % to preallocate it first as it changes size every iterartion
vectorDominant(i) = dominantFrequency;
%var = var+1;
%end
end
end
the argument i give it is processData(ax, 100, 0.1, 2) where ax is the
data vector and it returns the following ans =
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.2000
the whole result must have numbers like the last one (0.2000) not zeros

Answer 1

Every time through the loop you recreate vectorDominant to be a vector of zeros and then set one element of it to be the newly calculated value. Presumably the first 2 of the following lines should be done once before entering the loop.
n = (length(data)/1000);
vectorDominant = zeros(n,1);
vectorDominant(i) = dominantFrequency;
Presumably n should also be num_frames not the value calculated above.