function X = vaneck(data, fs, MyDelta,MyStartFreq,MyEndFreq)
%dada = audio data
%fs = sampling rate
%MyDelta = number of samples to perform FFT on
%MyStartFreq = starting frequency to match
%MyEndFreq = Ending frequency to match
%example
%plot(vaneck(data, fs, 1000, 1450, 1550))
%   use data from data
%   use a sampling rate of fs
%   1000 samples defines 1 bit
%   count "on" if there is a sound starting at 1450hz and ending at 1550hz)

i=1; %counter for sample #
delta=MyDelta; %number of samples comprising one bit
tmp = size(data);
MySize = tmp(1); %size of the entire sample
while( (delta*(i+1)) < MySize ) %loop for each sample until the end

    [A,B] = dtft( data( i*delta : (i+1)*delta ), 1/fs); %slice sample and perform dtft to get frequency ranges, store amplitude array in A, and frequency array in B
    tmp=ceil(size(B)/2); %j will store the index of the amplitude, start it halfway because we dont care about the negative mirror
    j=tmp(2);
    %j=1;
    tmp=size(B);
    MySizeB = tmp(2);
    while(j<MySizeB)   %from frequency 0 to up to the last recorded frequency
        if ((B(j)>MyStartFreq) && (B(j)<MyEndFreq)), break, end %if  MyStartFreq<frequency<MyEndFreq break, you have found the necessary J to index the amplitude array
        j = j + 1; %increment by 1 to get next frequency
    end
    Amplitude(i,1) = A(j,1); %store the amplitude for this sample
    i = i + 1; 
end

X = Amplitude;