File:Integerexponential,a=2,s=-1plot.png

#!/usr/bin/python
import numpy as np
import matplotlib.pyplot as plt
from mpmath import *
from pylab import rcParams
rcParams['figure.figsize'] = 10, 10

x=np.arange(-3,4,1);
x2=np.arange(-20,20,1);
def integerexp(a,t,s):
        return (1+a)**(t-s)
f=np.vectorize(lambda x: integerexp(2,x,-1))
y=f(x)
def returnzero(t):
        return 0
h=np.vectorize(returnzero)
y2=h(x2)

fig, ax = plt.subplots()

plt.xlabel(r'$t$')
plt.ylabel(r'$e_2(t,-1;\mathbb{Z})=3^{t+1}$')
plt.title(r'Time scale exponential function')

ylabels = [item.get_text() for item in ax.get_yticklabels()]
ylabels=[r'$0$',r'$3$',r'$9$',r'$27$',r'$81$']
ax.set_yticks([0,3,9,27,81])
ax.set_yticklabels(ylabels,horizontalalignment='right')

plt.scatter(x,y,color='Black',s=40)
plt.plot(x2,y2,'--',linewidth=2,color='Black')

plt.xlim([-3.4,3.4])

plt.savefig('integerexponential,a=2,s=-1plot.png',bbox_inches='tight',pad_inches=0.15)