% Demonstration script for iPeak function.  This is a demo script for 
% ipeak that demonstrates the operation and the typical measurement 
% errors of ipeak.  It generates a test signal consisting of several 
% Gaussian peaks, adds random noise, runs ipeak, then calculates the 
% errors between the actual and the measured peak positions, heights, 
% and widths.  Each time you run it you get a different set of peaks.
%   
increment=5;
x=[1:increment:4000];
% For each simulated peak, enter the amplitude, position, and width below
amp=randn(1,39);  % Amplitudes of the peaks  (Change if desired)
pos=[200:100:4000];   % Positions of the peaks (Change if desired)
wid=60.*ones(size(pos));   % Widths of the peaks (Change if desired)
Noise=.02; % Amount of random noise added to the signal. (Change if desired) 
% A = matrix containing one of the unit-amplidude peak in each of its rows
A = zeros(length(pos),length(x));
ActualPeaks=[0 0 0 0];
p=1;
for k=1:length(pos)
  if amp(k)>.2,  % Keep only those peaks above a certain amplitude
      % Create a series of Gaussian peaks
      A(k,:)=exp(-((x-pos(k))./(0.6006.*wid(k))).^2);
      % Assembles actual parameters into ActualPeaks matrix
      ActualPeaks(p,:) = [p pos(k) amp(k) wid(k)]; 
      p=p+1;
  end; 
end
z=amp*A;  % Multiplies each row by the corresponding amplitude and adds them up
y=z+Noise.*randn(size(z));  % Optionally adds random noise
% y=y+gaussian(x,0,4000); % Optionally adds a broad background signal
demodata=[x' y']; % Assembles x and y vectors into data matrix
% Now call iPeak, with specified values of AmpT, SlopeT, SmoothW, and FitW.
% (You can change theses values if desired).
MeasuredlPeaks=ipeak(demodata,0,0.1,0.003,5,13);
if length(ActualPeaks)==length(MeasuredlPeaks),
    disp('       Peak #    Position      Height       Width')
    diff=MeasuredlPeaks-ActualPeaks;
    PercentErrors=100.*diff./ActualPeaks;
    PercentErrors(:,1)=MeasuredlPeaks(:,1);
    PercentErrors=PercentErrors
    AveragePercentError=mean(abs(PercentErrors))
else
    disp('Not all peaks in the signal were detected')
end