CODEWITHSUNDEEP
matlabmaxcurve-fittinggaussian
Chris 'Namikaze Kurisu' Fraser
Chris 'Namikaze Kurisu' Fraser

Reputation: 55

Maximum of a fitted Gaussian in MATLAB

I need to find the maximum of a Gaussian I have fitted, below is my sample code (ignore the fact that it is a horrible fit to the Gaussian, they were just two spare matrices I had kicking around in my variables tray)

x=[10;2;6;1;7;5;3;4;8;9];
z1=[0;0;0;0;0;6;7;8;9;10];
cf1=fit(x,z1,'gauss1');
plot(x,z1,'.k')
hold on
plot(cf1,'r')

Any help you guys could give me would be greatly appreciated.

Upvotes: 0

Views: 4079

Answers (1)

Rody Oldenhuis
Rody Oldenhuis

Reputation: 38042

That's pretty basic math. Look at the output of 

>> cf1

cf1 = 
     General model Gauss1:
     cf1(x) =  a1*exp(-((x-b1)/c1)^2)
     Coefficients (with 95% confidence bounds):
       a1 =       5.187  (-0.4711, 10.85)
       b1 =       6.834  (-0.768, 14.44)
       c1 =       5.945  (-8.833, 20.72)

Now, armed with the wikipedia article on Gaussians, it's trivial to find the maximum: 

maximum_x = cf1.b1;
maximum_y = cf1.a1;

Same will be true for whatever other tool you use to fit the same function -- the coefficients a1 and b1 define the y and x locations of the maximum, respectively.

Upvotes: 3

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