MATLAB: How to use trapz for histogram

area under curvehisthistogramtrapz

I want to compute area under curve, when 2<x<8
how can i use trapz?
Help me please
my code:
a=[1,3,3,2,1,3,8,8,9,0,6,5,15,4,14,3,2,1,2,14]
aa=histogram(a'Normalization','probability')

Best Answer

Try this: 
a=[1,3,3,2,1,3,8,8,9,0,6,5,15,4,14,3,2,1,2,14];
aa = histogram(a,'Normalization','probability');
edgs = aa.BinEdges;
vals = aa.Values;
ctrs = edgs + mean(diff(edgs))/2;
lidx = (ctrs > 2) & (ctrs < 8);
AUC = trapz(ctrs(lidx), vals(lidx));
Related Question