Peakfunction

Purpose

Outputs the estimated peaks from parameters in (peakdef)

Synopsis

[y,peakdef] = peakfunction(peakdef,ax)

Description

Given the multi-record standard peak structure (peakdef) and the corresponding wavelength/frequency axis (ax), the peak parameters in the field (peakdef.param) are used to generate peaks. This function is called by PEAKFITS and the result is the output (fit), and the peak area estimates in (peakdef) are updated. See PEAKFITS for more information. This function calls PEAKGAUSSIAN, PEAKLORENTZIAN, PEAKPVOIGT1, and PEAKVOIGT2.

Inputs

• peakdef = standard peak structure (see PEAKSTRUCT) output by fitpeaks.

• ax = corresponding wavelength/frequency axis. This is also input to the function FITPEAKS. Peak positions are based on this axis.

Outputs

• y = estimated peaks based on the parameters in the input (peakdef).

• peakdef = the original input (peakdef) with the area field estimated.

Examples

ax = 0:0.1:100;

y = peakgaussian([2 51 8],ax);%Make known peak

%Define first estimate and peak type

peakdef = peakstruct;

peakdef.param = [0.1 43 5]; %coef, position, spread

peakdef.lb = [0.0 0 0.0001]; %lower bounds on param

peakdef.penlb = [1 1 1];

peakdef.ub = [10 99.9 40]; %upper bounds on params

peakdef.penub = [1 1 1];

%Estimate fit and plot

yint = peakfunction(peakdef,ax);

[peakdef,fval,exitflag,out] = fitpeaks(peakdef,y,ax);

yfit = peakfunction(peakdef,ax); figure

plot(ax,yint,'m',ax,y,'b',ax,yfit,'r--')

legend('Initial','Actual','Fit')

See Also

fitpeaks, peakgaussian, peaklorentzian, peakpvoigt1, peakpvoigt2, peakstruct,peaksigmoid