WX中的数学文本

演示如何将数学文本转换为wx.Bitmap，以便在wxPython的各种控件中显示。

  1. import matplotlib
  2. matplotlib.use("WxAgg")
  3. from matplotlib.backends.backend_wxagg import FigureCanvasWxAgg as FigureCanvas
  4. from matplotlib.backends.backend_wx import NavigationToolbar2Wx
  5. from matplotlib.figure import Figure
  6. import numpy as np
  8. import wx
  10. IS_GTK = 'wxGTK' in wx.PlatformInfo
  11. IS_WIN = 'wxMSW' in wx.PlatformInfo

This is where the “magic” happens.

  1. from matplotlib.mathtext import MathTextParser
  2. mathtext_parser = MathTextParser("Bitmap")
  5. def mathtext_to_wxbitmap(s):
  6.     ftimage, depth = mathtext_parser.parse(s, 150)
  7.     return wx.Bitmap.FromBufferRGBA(
  8.         ftimage.get_width(), ftimage.get_height(),
  9.         ftimage.as_rgba_str())
  1. functions = [
  2.     (r'$\sin(2 \pi x)$', lambda x: np.sin(2*np.pi*x)),
  3.     (r'$\frac{4}{3}\pi x^3$', lambda x: (4.0/3.0)*np.pi*x**3),
  4.     (r'$\cos(2 \pi x)$', lambda x: np.cos(2*np.pi*x)),
  5.     (r'$\log(x)$', lambda x: np.log(x))
  6. ]
  9. class CanvasFrame(wx.Frame):
  10.     def __init__(self, parent, title):
  11.         wx.Frame.__init__(self, parent, -1, title, size=(550, 350))
  13.         self.figure = Figure()
  14.         self.axes = self.figure.add_subplot(111)
  16.         self.canvas = FigureCanvas(self, -1, self.figure)
  18.         self.change_plot(0)
  20.         self.sizer = wx.BoxSizer(wx.VERTICAL)
  21.         self.add_buttonbar()
  22.         self.sizer.Add(self.canvas, 1, wx.LEFT | wx.TOP | wx.GROW)
  23.         self.add_toolbar()  # comment this out for no toolbar
  25.         menuBar = wx.MenuBar()
  27.         # File Menu
  28.         menu = wx.Menu()
  29.         m_exit = menu.Append(wx.ID_EXIT, "E&xit\tAlt-X", "Exit this simple sample")
  30.         menuBar.Append(menu, "&File")
  31.         self.Bind(wx.EVT_MENU, self.OnClose, m_exit)
  33.         if IS_GTK or IS_WIN:
  34.             # Equation Menu
  35.             menu = wx.Menu()
  36.             for i, (mt, func) in enumerate(functions):
  37.                 bm = mathtext_to_wxbitmap(mt)
  38.                 item = wx.MenuItem(menu, 1000 + i, " ")
  39.                 item.SetBitmap(bm)
  40.                 menu.Append(item)
  41.                 self.Bind(wx.EVT_MENU, self.OnChangePlot, item)
  42.             menuBar.Append(menu, "&Functions")
  44.         self.SetMenuBar(menuBar)
  46.         self.SetSizer(self.sizer)
  47.         self.Fit()
  49.     def add_buttonbar(self):
  50.         self.button_bar = wx.Panel(self)
  51.         self.button_bar_sizer = wx.BoxSizer(wx.HORIZONTAL)
  52.         self.sizer.Add(self.button_bar, 0, wx.LEFT | wx.TOP | wx.GROW)
  54.         for i, (mt, func) in enumerate(functions):
  55.             bm = mathtext_to_wxbitmap(mt)
  56.             button = wx.BitmapButton(self.button_bar, 1000 + i, bm)
  57.             self.button_bar_sizer.Add(button, 1, wx.GROW)
  58.             self.Bind(wx.EVT_BUTTON, self.OnChangePlot, button)
  60.         self.button_bar.SetSizer(self.button_bar_sizer)
  62.     def add_toolbar(self):
  63.         """Copied verbatim from embedding_wx2.py"""
  64.         self.toolbar = NavigationToolbar2Wx(self.canvas)
  65.         self.toolbar.Realize()
  66.         # By adding toolbar in sizer, we are able to put it at the bottom
  67.         # of the frame - so appearance is closer to GTK version.
  68.         self.sizer.Add(self.toolbar, 0, wx.LEFT | wx.EXPAND)
  69.         # update the axes menu on the toolbar
  70.         self.toolbar.update()
  72.     def OnChangePlot(self, event):
  73.         self.change_plot(event.GetId() - 1000)
  75.     def change_plot(self, plot_number):
  76.         t = np.arange(1.0, 3.0, 0.01)
  77.         s = functions[plot_number][1](t)
  78.         self.axes.clear()
  79.         self.axes.plot(t, s)
  80.         self.canvas.draw()
  82.     def OnClose(self, event):
  83.         self.Destroy()
  86. class MyApp(wx.App):
  87.     def OnInit(self):
  88.         frame = CanvasFrame(None, "wxPython mathtext demo app")
  89.         self.SetTopWindow(frame)
  90.         frame.Show(True)
  91.         return True
  93. app = MyApp()
  94. app.MainLoop()

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