from matplotlib import pyplot as plt
%matplotlib inline
import numpy as np
x = np.arange(250)
y = x+1
z = x*10
t = 2*x - 15
q = list(map(lambda p : p+2000 if p < 50 else np.log(p) + 15,x.tolist()))
fig=plt.figure(figsize=(18, 16), dpi= 80, facecolor='w', edgecolor='k')
plt.plot(x,y)
plt.plot(x,z)
plt.plot(x,t)
plt.plot(x,q)
plt.yticks(np.arange(min(z), max(z)+1, 100.0))