.. _pylab_examples-mathtext_examples:

pylab_examples example code: mathtext_examples.py
=================================================



.. plot:: /home/tcaswell/source/p/matplotlib/doc/mpl_examples/pylab_examples/mathtext_examples.py

::

    """
    Selected features of Matplotlib's math rendering engine.
    """
    from __future__ import print_function
    import matplotlib.pyplot as plt
    import os
    import sys
    import re
    import gc
    
    # Selection of features following "Writing mathematical expressions" tutorial
    mathtext_titles = {
        0: "Header demo",
        1: "Subscripts and superscripts",
        2: "Fractions, binomials and stacked numbers",
        3: "Radicals",
        4: "Fonts",
        5: "Accents",
        6: "Greek, Hebrew",
        7: "Delimiters, functions and Symbols"}
    n_lines = len(mathtext_titles)
    
    # Randomly picked examples
    mathext_demos = {
        0: r"$W^{3\beta}_{\delta_1 \rho_1 \sigma_2} = "
        r"U^{3\beta}_{\delta_1 \rho_1} + \frac{1}{8 \pi 2} "
        r"\int^{\alpha_2}_{\alpha_2} d \alpha^\prime_2 \left[\frac{ "
        r"U^{2\beta}_{\delta_1 \rho_1} - \alpha^\prime_2U^{1\beta}_"
        r"{\rho_1 \sigma_2} }{U^{0\beta}_{\rho_1 \sigma_2}}\right]$",
    
        1: r"$\alpha_i > \beta_i,\ "
        r"\alpha_{i+1}^j = {\rm sin}(2\pi f_j t_i) e^{-5 t_i/\tau},\ "
        r"\ldots$",
    
        2: r"$\frac{3}{4},\ \binom{3}{4},\ \stackrel{3}{4},\ "
        r"\left(\frac{5 - \frac{1}{x}}{4}\right),\ \ldots$",
    
        3: r"$\sqrt{2},\ \sqrt[3]{x},\ \ldots$",
    
        4: r"$\mathrm{Roman}\ , \ \mathit{Italic}\ , \ \mathtt{Typewriter} \ "
        r"\mathrm{or}\ \mathcal{CALLIGRAPHY}$",
    
        5: r"$\acute a,\ \bar a,\ \breve a,\ \dot a,\ \ddot a, \ \grave a, \ "
        r"\hat a,\ \tilde a,\ \vec a,\ \widehat{xyz},\ \widetilde{xyz},\ "
        r"\ldots$",
    
        6: r"$\alpha,\ \beta,\ \chi,\ \delta,\ \lambda,\ \mu,\ "
        r"\Delta,\ \Gamma,\ \Omega,\ \Phi,\ \Pi,\ \Upsilon,\ \nabla,\ "
        r"\aleph,\ \beth,\ \daleth,\ \gimel,\ \ldots$",
    
        7: r"$\coprod,\ \int,\ \oint,\ \prod,\ \sum,\ "
        r"\log,\ \sin,\ \approx,\ \oplus,\ \star,\ \varpropto,\ "
        r"\infty,\ \partial,\ \Re,\ \leftrightsquigarrow, \ \ldots$"}
    
    
    def doall():
        # Colors used in mpl online documentation.
        mpl_blue_rvb = (191./255., 209./256., 212./255.)
        mpl_orange_rvb = (202/255., 121/256., 0./255.)
        mpl_grey_rvb = (51./255., 51./255., 51./255.)
    
        # Creating figure and axis.
        plt.figure(figsize=(6, 7))
        plt.axes([0.01, 0.01, 0.98, 0.90], facecolor="white", frameon=True)
        plt.gca().set_xlim(0., 1.)
        plt.gca().set_ylim(0., 1.)
        plt.gca().set_title("Matplotlib's math rendering engine",
                            color=mpl_grey_rvb, fontsize=14, weight='bold')
        plt.gca().set_xticklabels("", visible=False)
        plt.gca().set_yticklabels("", visible=False)
    
        # Gap between lines in axes coords
        line_axesfrac = (1. / (n_lines))
    
        # Plotting header demonstration formula
        full_demo = mathext_demos[0]
        plt.annotate(full_demo,
                     xy=(0.5, 1. - 0.59*line_axesfrac),
                     xycoords='data', color=mpl_orange_rvb, ha='center',
                     fontsize=20)
    
        # Plotting features demonstration formulae
        for i_line in range(1, n_lines):
            baseline = 1. - (i_line)*line_axesfrac
            baseline_next = baseline - line_axesfrac*1.
            title = mathtext_titles[i_line] + ":"
            fill_color = ['white', mpl_blue_rvb][i_line % 2]
            plt.fill_between([0., 1.], [baseline, baseline],
                             [baseline_next, baseline_next],
                             color=fill_color, alpha=0.5)
            plt.annotate(title,
                         xy=(0.07, baseline - 0.3*line_axesfrac),
                         xycoords='data', color=mpl_grey_rvb, weight='bold')
            demo = mathext_demos[i_line]
            plt.annotate(demo,
                         xy=(0.05, baseline - 0.75*line_axesfrac),
                         xycoords='data', color=mpl_grey_rvb,
                         fontsize=16)
    
        for i in range(n_lines):
            s = mathext_demos[i]
            print(i, s)
        plt.show()
    
    if '--latex' in sys.argv:
        # Run: python mathtext_examples.py --latex
        # Need amsmath and amssymb packages.
        fd = open("mathtext_examples.ltx", "w")
        fd.write("\\documentclass{article}\n")
        fd.write("\\usepackage{amsmath, amssymb}\n")
        fd.write("\\begin{document}\n")
        fd.write("\\begin{enumerate}\n")
    
        for i in range(n_lines):
            s = mathext_demos[i]
            s = re.sub(r"(?<!\\)\$", "$$", s)
            fd.write("\\item %s\n" % s)
    
        fd.write("\\end{enumerate}\n")
        fd.write("\\end{document}\n")
        fd.close()
    
        os.system("pdflatex mathtext_examples.ltx")
    else:
        doall()
    

Keywords: python, matplotlib, pylab, example, codex (see :ref:`how-to-search-examples`)