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

xlim = -2,2; fig.gca().set_xlim(xlim)
ylim = -0.1,1.1; fig.gca().set_ylim(ylim)
mplwp.mark_axeszero(fig.gca())

import mpmath
f = lambda x: (mpmath.besselj(1, 2*pi*x) / (pi*x) if x != 0 else 1.0)**2
x = np.linspace(xlim[0], xlim[1], 5001)
y = [f(xx) for xx in x]
plt.plot(x, y, label=r'$\left(\,\frac{J_1(2\pi x)}{\pi x}^{\;{}_2}\!\!\!\right)\,}$')

plt.legend(loc='upper right').get_frame().set_alpha(0.9)
plt.setp(fig.gca().get_legend().get_texts(), fontsize=19/log(2))

plt.savefig(name)
mplwp.postprocess(name)