How do you fit a gamma distribution?
Hi There How do you fit a gamma distribution to random data while fixing one of the gamma distribution parameters? Lets say we fix the shaping factor k for example and try to find the scaling factor Thetha of the gamma pdf? How is this done in Matlab?
Kshitij Singh answered .
2025-11-20
Expanding on what Wayne wrote, you can supply your fixed-parameter version of the gamma distribution to the mle function. Try this:
x = gamrnd(1.1,100,100,1); ab = gamfit(x) % fit a and b b = mle(x,'pdf',@(x,b)gampdf(x,1,b),'start',1) % fix a=1 % compare the empirical distribution and two fits ecdf(x); xx = linspace(0,max(x)); line(xx,gamcdf(xx,ab(1),ab(2)),'color','r') line(xx,gamcdf(xx,1,b),'color','c')