TVSD/_code/code_utils_v2/ez_spectrogram.m

function [wincent,f,y] = ez_spectrogram(x,Fs,win,overlap)

%WORK IN PROGRESS
%NEED to add averaging and correct scaling for graphs

%Measures and displays a spectrogram using ez_powermeasure and the
%short-time FFT technique with a Hann window. x should be a time series
%(row or column vector), Fs is the sample frequency, win is the length of
%each time window (in samples) and overlap how many samples to move the
%window by each time

%M.W.Self 2014

if nargin < 3
    win = round(length(x)./10);
end
if nargin < 4
    overlap = round(win/2);
end

%USe a Hann window
HW = 1;

%Calculate how many windows we need
nsamps = length(x);
%start the first window at sample 1 and keep going until we can no longer
%fit a whole window into the remaining time-series
nwins = floor((nsamps-win)./overlap)+1;

clear y
startwin = 1;
wincent = zeros(1,nwins);
for n = 1:nwins
    
    endwin = startwin+win-1;
    
    %y has same dims as x?
    [f,y(:,n)] = ez_powermeasure(x(startwin:endwin),Fs,HW);
    wincent(n) = (startwin+endwin)/2;
    
    %Shift the window
    startwin = startwin+overlap;
    
end

%Plot
if 0
figure,surf(wincent,f,y),view([0 90]),shading interp
ylim([0 Fs/2])
end

return