#!/usr/bin/python
# -*- coding: utf8 -*-

import matplotlib.pyplot as plt
import matplotlib as mpl
import numpy as np
from math import *

code_website = 'http://commons.wikimedia.org/wiki/User:Geek3/mplwp'
try:
    import mplwp
except ImportError, er:
    print 'ImportError:', er
    print 'You need to download mplwp.py from', code_website
    exit(1)

name = 'mplwp_arsech.svg'
fig = mplwp.fig_standard(mpl)

xlim = -0.2,1.2+1e-12; fig.gca().set_xlim(xlim)
ylim = -1,6; fig.gca().set_ylim(ylim)
mplwp.mark_axeszero(fig.gca())

def sech(x): return 1.0 / cosh(x)
y = np.linspace(0, ylim[1], 5001)
x = [sech(yy) for yy in y]

plt.plot(x, y, label='arsech')
plt.plot([1], [0], 'o', color=fig.gca().lines[-1].get_color())

plt.legend(loc='upper right').get_frame().set_alpha(0.9)
plt.savefig(name)
mplwp.postprocess(name)