def poisson_pmf():
rv=Pie(4.5)#the average incident is 4.5
x = np.arange(0, 11, 1)#return evenly spaced values within 1 interval between [1,11)
y = rv.pmf(x)#probability mass function
plt.bar(x, y, width=0.6, color='grey')#make bar chart
plt.savefig('fig.png')
def geom_pmf():
rv=G(0.2)#probability of success is 0.2
x = np.arange(1, 11, 1)#return evenly spaced values within 1 interval between [1,11)
y = rv.pmf(x)#probability mass function
plt.bar(x, y, width=0.6, color='grey')#make bar chart
plt.savefig('fig.png')
def draw():
#get input data
menMeans = (20, 35, 30, 35, 27)
menStd = (2, 3, 4, 1, 2)
womenMeans = (25, 32, 34, 20, 25)
womenStd = (3, 5, 2, 3, 3)
ind = np.arange(5)
width = 0.35
# the histogram of the data
plt.bar(ind, menMeans, width, color='r')
plt.bar(ind+width, womenMeans, width, color='y')
#show image
plt.savefig('fig.png')