File:Siplot.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(-30,30,0.001);

f=np.vectorize(si)
y1=f(x)
def g(x):
        return 1.570796
def h(x):
        return -1.570796
j=np.vectorize(g)
k=np.vectorize(h)
y2=j(x)
y3=k(x)

fig, ax = plt.subplots()

xlabels = [item.get_text() for item in ax.get_xticklabels()]
xlabels=[r'$-25$',r'$-20$',r'$-15$',r'$-10$',r'$-5$',r'$0$',r'$5$',r'$10$',r'$15$',r'$20$',r'$25$']
ax.set_xticks([-25,-20,-15,-10,-5,0,5,10,15,20,25])
ax.set_xticklabels(xlabels,horizontalalignment='center')

ylabels = [item.get_text() for item in ax.get_yticklabels()]
ylabels=[r'$-\frac{\pi}{2}$',r'$0$',r'$\frac{\pi}{2}$']
ax.set_yticks([-1.570796,0,1.570596])
ax.set_yticklabels(ylabels,horizontalalignment='right')

plt.xlabel(r'$x$')
plt.ylabel(r'$\mathrm{Si}(x)$')

plt.plot(x,y1,linewidth=2,color='Black')
plt.plot(x,y2,'--',linewidth=2,color='Black')
plt.plot(x,y3,'--',linewidth=2,color='Black')

plt.savefig('siplot.png',bbox_inches='tight',pad_inches=0.15)