Why histfit cannot fit my data very well?

I tried to fit the histogram as shown in the fig. I tried normal distribution and gamma fitting (preferred) with histfit. but histfit cannot fit the data very well. Any suggestion? http://www.imagesup.net/?di=0135735909615

Answer 1

[Walter Roberson]

Have you considered the possibility that the data does not fit those distributions well enough for you to be comfortable? Have you considered trying

ttest(x, mean(x))

to find the confidence that the data is normally distributed?

[Tom Lane]

You could use lillietest or jbtest for that. I wouldn't recommend ttest.

Answer 2

[Tom Lane]

Try fitting the 'gev' (generalized extreme value) or 'tlocationscale" (location/scale shift of the t) distribution.