from pylab import *
from scipy import *
from math import *
from numpy import *

N = 5
k = 0.5
t = arange(0.0, 100, 1)

def Nash(t,N,k):
    h = (t/k)**(N-1)*exp((-t/k)/(k*gamma(N)))
    return h

plot(t, Nash(t,N,k))
xtext = xlabel('time')
ytext = ylabel('response')
setp(xtext, size='medium', name='courier', weight='bold', color='g')
setp(ytext, size='medium', name='helvetica', weight='light', color='b')
show()