#!/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_polygamma04_largey.svg'
    fig = mplwp.fig_standard(mpl)
    
    xlim = -2,4; fig.gca().set_xlim(xlim)
    ylim = -100,250; fig.gca().set_ylim(ylim)
    mplwp.mark_axeszero(fig.gca())
    
    import mpmath
    for m in range(4+1):
        for i, tlim in enumerate([(-2, -1), (-1, -0), (0, 4)]):
            if tlim[1] <= 0.0:
                x = np.linspace(tlim[0], tlim[1], 1001)[1:-1]
            else:
                x = np.linspace(tlim[0], tlim[1], 5001)[1:]
            y = [mpmath.psi(m, xx) for xx in x]
            label = u'\u03c8'
            if m != 0:
                label += mplwp.unicode_sub(m)
            if i == 0:
                plt.plot(x, y, label=label)
            else:
                plt.plot(x, y, color=fig.gca().lines[-1].get_color())
    
    plt.legend(loc='upper right').get_frame().set_alpha(0.9)
    
    plt.savefig(name)
    mplwp.postprocess(name)