Plot a poisson distribution graph in python

Question

I would like to plot the Poisson function in Python using Matplotlib. The function is (exp(-5)*5^x)/factorial(x)

import numpy as np
import math
import matplotlib.pyplot as plt

t = np.arange(0, 20, 0.1)
d = []

for i in t:
    p = pow(5,i)
    q = p/math.factorial(i)
    d.append(q)

plt.plot( t, np.exp(-5)*d, 'bs')
plt.show()

But I get this error."Only size^1 arrays can be converted to Python scalars". How can I plot this graph? Thanks in advance

Solution

i think your function is not right: it's exp(-5)

import numpy as np
import matplotlib.pyplot as plt
from scipy.special import factorial

t = np.arange(0, 20, 0.1)
d = np.exp(-5)*np.power(5, t)/factorial(t)

plt.plot(t, d, 'bs')
plt.show()

Comments

[Thomas Kühn]

Should it be pow(5,i) and factorial(i) instead of t?

[Matt VanEseltine]

Note that scipy.misc.factorial is deprecated and is, as of 1.0, scipy.special.factorial.