#!/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_arcoth.svg'
fig = mplwp.fig_standard(mpl)

xlim = -5.5,5.5; fig.gca().set_xlim(xlim)
ylim = -3,3; fig.gca().set_ylim(ylim)
fig.gca().xaxis.set_major_locator(mpl.ticker.MultipleLocator(1))
mplwp.mark_axeszero(fig.gca())

f = lambda x: 1.0 / tanh(x) if abs(x) > 1e-2 else float('NaN')
y = np.linspace(ylim[0], ylim[1], 5001)
x = [f(yy) for yy in y]

plt.plot(x, y, label='arcoth')
plt.legend(loc='upper left').get_frame().set_alpha(0.9)
    
plt.savefig(name)
mplwp.postprocess(name)