Peak finding and measurement: RedrawPeak.m - File Exchange

Code covered by the BSD License

Highlights from
Peak finding and measurement

P=ipeak(DataMatrix,PeakD,AmpT... Version 3.91, FitW now equals number of points, not number of intervals;
AmpTSlider(n,h) Changes AmpThreshold when the AmpThreshold slider is moved.
BGSlider(n,h) Called when the BG slider is clicked.
FitSlider(n,h) Changes FitWidth when the FitWidth slider is moved.
P=findpeaks(x,y,SlopeThreshol... function P=findpeaks(x,y,SlopeThreshold,AmpThreshold,smoothwidth,peakgroup)
P=findpeaks(x,y,SlopeThreshol... function P=findpeaks(x,y,SlopeThreshold,AmpThreshold,smoothwidth,peakgroup,smoothtype)
P=findpeakslidersRedraw(x,y,S... Redraws graph for FindPeakSliders when slider are moved.
PeakSlider(n,h) Changes PeakNumber when the Peak slider is moved.
SlopeTSlider(n,h) Changes SlopeThreshold when the SlopeThreshold slider is moved.
SmoothSlider(n,h) Changes SmoothWidth when the SmoothWidth slider is moved.
V=findvalleys(x,y,SlopeThresh... function P=findvalleys(x,y,SlopeThreshold,AmpThreshold,smoothwidth,peakgroup,smoothtype)
[index,closestval]=val2ind(x,... Returns the index and the value of the element of vector x that is closest to val
d=deriv(a) First derivative of vector using 2-point central difference.
d=secderiv(a) Second derivative of vector using 3-point central difference.
exp(-((x-pos)./(0.6006.*wid))...
lorentzian(x,position,width)
rtslid(fig,f,hh,varargin) RTSLID Slider widget that responds to dragging realtime
smoothwidth. Works well with ...
sy=condense(y,n) Condense y by a factor of n, where n is a non-zero positive integer.
Demo4peaks.m
DemoFindPeak.m
DemoFindPeak.m
DemoFindPeakSliders.m
DemoFindPeakSliders2.m
DemoFindPeakSlidersG.m
FindPeakSliders.m
FindPeakSlidersG.m
RedrawPeak.m
TestPeakfind.m
ipeakdemo.m
ipeakdemo1.m
ipeakdemo2.m
ipeakdemo3.m
ipeakdemo4.m
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from Peak finding and measurement by Tom O'Haver
Function to locate and measure the positive peaks and valleys in noisy data sets.

RedrawPeak.m

% Redraws graph for FindPeakSliders when Peak slider is moved.
% Tom O'Haver (toh@umd.edu). Version 2 April, 2009
warning off MATLAB:divideByZero
warning off MATLAB:polyfit:PolyNotUnique
global x
global y
global SlopeThreshold 
global AmpThreshold  
global SmoothWidth
global FitWidth
global PeakNumber
global P
axes(h);
if PeakNumber>max(P(:,1)),
    PeakNumber=max(P(:,1));
end
P=findpeaks(x,y,SlopeThreshold,AmpThreshold,SmoothWidth,FitWidth);
FitWidth=round(real(FitWidth));
n1=val2ind(x,P(PeakNumber,2))-FitWidth;
if n1<1, n1=1;,end
n2=val2ind(x,P(PeakNumber,2))+FitWidth;
if n2>length(y), n2=length(y);,end
PeakRange=[n1:n2];
plot(x(PeakRange),y(PeakRange),'m.');hold on
n1=val2ind(x,P(PeakNumber,2))-round(FitWidth/2);
n2=val2ind(x,P(PeakNumber,2))+round(FitWidth/2);
if n1<1, n1=1;,end
if n2>length(y), n2=length(y);,end
PlotRange=[n1:n2];
xx=x(PlotRange);
yy=y(PlotRange);
[coef,S,MU]=polyfit(xx,log(abs(yy)),2);  % Fit parabola to log10 of sub-group
c1=coef(3);c2=coef(2);c3=coef(1);
PeakX=-((MU(2).*c2/(2*c3))-MU(1));   % Compute peak position and height or fitted parabola
PeakY=exp(c1-c3*(c2/(2*c3))^2);
MeasuredWidth=norm(MU(2).*2.35703/(sqrt(2)*sqrt(-1*c3)));
plot(xx,PeakY.*gaussian(xx,PeakX,MeasuredWidth));
hold off
title(['Peak number ' num2str(PeakNumber) '    Height = ' num2str(PeakY) '    Position =' num2str(round(100*PeakX)/100) '    Width =' num2str(round(10*MeasuredWidth)/10)])
text(P(PeakNumber,2),0.9.*P(PeakNumber,3),num2str(PeakNumber))
xlabel(['SlopeT = ' num2str(SlopeThreshold) '   AmpT = ' num2str(AmpThreshold) '   SmoothWidth = ' num2str(SmoothWidth) '   FitWidth = ' num2str(FitWidth) ])
%axis([x(PeakRange(1)) x(length(PeakRange)) min(y) max(y)]); % Update plot
currentaxis=axis;
text(currentaxis(1),0.99.*currentaxis(4),['Set peak slider to zero to see all peaks'])

Highlights from Peak finding and measurement

Highlights from
Peak finding and measurement