Random Gamma distribution using python

Question

I am trying to fit a random gamma distribution on my data using python. I have written so far following codes

a = 10
b = 1
n=25
n_classes = 16       
true_val = []
for i in np.arange(n_classes):
    gamma_process= np.cumsum(np.random.gamma(n,a,b))   # to get cummaltive sum of the fit
    true_val = gamma_process   

When I ran this code, it does not give any error but the value i am getting in true_val is only one. I suppose to get list of values. I am not getting an idea where I am making a mistake. I would be grateful if you can help me on this. Thanks in advance

Answer 1

Try to append to list of results:

true_val = true_val + [gamma_process[0]]

or better:

 true_val.append(float(gamma_process))

Now resulting list is of type integer.

Answer 2

That is due to size of gamma distribution. Please test when b>2.

In numpy gamma function,

numpy.random.gamma(shape, scale=1.0, size=None)

Please check again.