how to make a curve of Poisson, Rayleih, t , ....etc distribution of my random data (in histogram)

I am looking for the best shape that can fit with my histogram(in pdf). I tried with dfittool, but its does not include all types of distribution. and also I used the goodness fit.

Answer 1

[the cyclist]

If you have the Statistics and Machine Learning Toolboox, then you could use the fitdist function. It will fit a large variety of functional forms.

[Ahmed Abdalazeez]

Thank you dear for answer.

I used fitdist : pd = fitdist(my_data,'Poisson'); h = chi2gof(my_data,'CDF',pd), where the h gave me 0, which means that my data distibuted as a Poisson, and now I want make a Poisson curve on my data histogram. How can I extract it from pd ?

THanks in advance!

[the cyclist]

Use the pdf function, with the pd input.

% Set seed for reproducibility
rng default

% Generate poisson-distributed data.
x = poissrnd(5,10000,1);

% Fit a poisson distribution
pd = fitdist(x,'poisson');

% Calculate the theoretical PDF from the fit parameters
x_range = 0:10;
probability_predicted = pdf(pd,x_range);

% Plot histogram and fit
figure
hold on
histogram(x,-0.5:10.5,'Normalization','probability')
h = plot(x_range,probability_predicted,'.-');
set(h,'MarkerSize',24)

[Andrés F Vásquez]

Using this script as base, how could I plot also certain basic statistics such as mean, median, mode, and std. deviation (including legends in the chart)?

[the cyclist]

I'm going to assume you know how to get the values of the statistics. (If not, just google the statistic name along with matlab and you will find that.)

For adding them to the plot, here are a few commands that you could find useful:

• annotation -- add a wide variety of annotations (including textboxes) to a plot
• text -- add text to a plot; not as versatile as annotation, but simpler
• legend -- add legend
• sprintf -- convert a numerical variable to a string, so that it can be used in the above commands