I am using a different probability distribution to fit a data but the tail didn't() reach zero (at x-axis)

I want to determine the 99% of the area under curve of this probability ditribution.

I use this code to produce the figure:

`paramEsts = gevfit(data); %estimate parameter`

xgrid = linspace(0,18,100);pdfEst = gevpdf(xgrid,paramEsts(1),paramEsts(2),paramEsts(3)); hold on;line(xgrid,pdfEst,'color','r')

when I was fitting the normal distribution. I got the value of 99% of the curve using:

` p= normspec([6.5,inf],mu,sigma);`

but I didn't know how to get it with generalized extreme value distribution?

## Best Answer