from numpy import linspace, append
from math import cosh, sin, cos, pi
from matplotlib.pyplot import *
from mpl_toolkits.axes_grid.axislines import SubplotZero

fig = figure(figsize=(4,4))
ax = SubplotZero(fig,111)
fig.add_subplot(ax)
ax.grid(True)
ax.set_ylim(-1,1)
ax.set_xlim(-1,1)
for direction in ["xzero","yzero"]:
	ax.axis[direction].set_axisline_style("-|>")
	ax.axis[direction].set_visible(True)
for direction in ["left","right","bottom","top"]:
	ax.axis[direction].set_visible(False)

theta = linspace(-5*pi,5*pi,150)
X, Y = [],[]
for x in theta:
	X = append(X,cos(x)/cosh(x/3.))
	Y = append(Y,sin(x)/cosh(x/3.))
ax.plot(X,Y)
ax.text(1,0.1,r"x")
ax.text(-0.1,1,r"y")
#fig.show()
fig.savefig("Poinsot1.svg",bbox_inches="tight",\
	pad_inches=.15)