Normal distribution problem using histfit

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Vlatko Milic
Vlatko Milic le 17 Mai 2018
Commenté : Vlatko Milic le 17 Mai 2018
Hi MatLab-friends,
I have a question about histfit. My dataset only contains positive (or 0s) values but when I make my histfit, the normal distribution goes from negative values. How can I make the distribution line only consider positive values?
Attaching figure. How I want the distribution to look is seen with the black line.
Thank you in advance.
P.S.
The code I use now is:
F=d_f_t(:,2) %
n_d=histfit(F)
  2 commentaires
dpb
dpb le 17 Mai 2018
The distribution you drew doesn't represent the data well at all; the normal is a very bad choice being symmetric and unbounded; for a continuous distribution you might try lognormal.
Vlatko Milic
Vlatko Milic le 17 Mai 2018
Thank you very much, you are correct!

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the cyclist
the cyclist le 17 Mai 2018
If @dpb had made his comment as an answer, I would have upvoted it.
Your data are clearly not normally distributed. Is there a particular reason that you wanted to fit them with a normal?
You can use the histfit function with a different underlying distribution. dpb's suggestion of a lognormal looks like an excellent choice, from a purely empirical point of view (but you may know something about the underlying process that makes some other distribution a better choice). See the documentation for details, but for example ...
n_d = histfit(F,[ ],'lognormal')
should give you something much better than you have now.

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