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<p class="MsoNormal">Hi<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I am new to Matplotlib and am struggling a bit to differentiate between the OO and pyplot interfaces. I’m actually working with the Kivy GUI framework and trying to plot 4 subplots on a single figure, to be displayed by Kivy. Here’s a
snippet of my code:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">def create_plot(self):<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> self.fig, ((self.ax0, self.ax1), (self.ax2, self.ax3)) = plt.subplots(nrows=2, ncols=2)<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> self.ax0.set_title("A")<o:p></o:p></p>
<p class="MsoNormal"> self.ax0.grid(True, lw = 2, ls = '--', c = '.75')<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> self.ax1.set_title("B")<o:p></o:p></p>
<p class="MsoNormal"> self.ax1.grid(True, lw = 2, ls = '--', c = '.75')<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> self.ax2.set_title("C")<o:p></o:p></p>
<p class="MsoNormal"> self.ax2.grid(True, lw = 2, ls = '--', c = '.75')<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> self.ax3.set_title("D")<o:p></o:p></p>
<p class="MsoNormal"> self.ax3.grid(True, lw = 2, ls = '--', c = '.75')<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> #plt.tight_layout()<o:p></o:p></p>
<p class="MsoNormal"> plt.show()<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> canvas = self.fig.canvas<o:p></o:p></p>
<p class="MsoNormal"> self.add_widget(canvas)<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">What worries me is that I am calling plt methods and assigning the results to my objects. Is plt the state machine interface and not the OO interface, or is this OK?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Secondly, I want to periodically update the plotted lines, so I have a plot method that does this:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> def plot(self, xCoords, yCoords):<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> if len(self.ax0.lines) > 0:<o:p></o:p></p>
<p class="MsoNormal"> self.ax0.lines.pop(0)<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> line = self.ax0.plot(xCoords, yCoords, color='blue')<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> canvas = self.fig.canvas<o:p></o:p></p>
<p class="MsoNormal"> canvas.draw()<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Does that look ok? Can I just pop the existing line, or should I reuse the existing line?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Lastly, and most difficult, if I enable:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal" style="text-indent:36.0pt">plt.tight_layout()<o:p></o:p></p>
<p class="MsoNormal" style="text-indent:36.0pt"><o:p> </o:p></p>
<p class="MsoNormal">I get an exception:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB">C:\Kivy-1.9.0-py3.4-win32-x64\Python34\lib\site-packages\matplotlib\tight_layout.py:225: UserWarning: tight_layout
: fa</span><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black;border:none windowtext 1.0pt;padding:0cm;mso-fareast-language:EN-GB">lling back to Agg renderer</span><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> warnings.warn("tight_layout : falling back to Agg renderer")<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> Traceback (most recent call last):<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> File "main.py", line 1117, in <module><o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> GuiApp().run()<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> File "C:\Kivy-1.9.0-py3.4-win32-x64\Python34\lib\site-packages\kivy\app.py", line 801, in run<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> self.load_kv(filename=self.kv_file)<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> File "C:\Kivy-1.9.0-py3.4-win32-x64\Python34\lib\site-packages\kivy\app.py", line 598, in load_kv<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> root = Builder.load_file(rfilename)<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> File "C:\Kivy-1.9.0-py3.4-win32-x64\Python34\lib\site-packages\kivy\lang.py", line 1801, in load_file<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> return self.load_string(data, **kwargs)<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> File "C:\Kivy-1.9.0-py3.4-win32-x64\Python34\lib\site-packages\kivy\lang.py", line 1880, in load_string<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> self._apply_rule(widget, parser.root, parser.root)<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> File "C:\Kivy-1.9.0-py3.4-win32-x64\Python34\lib\site-packages\kivy\lang.py", line 2038, in _apply_rule<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> self._apply_rule(child, crule, rootrule)<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> File "C:\Kivy-1.9.0-py3.4-win32-x64\Python34\lib\site-packages\kivy\lang.py", line 2037, in _apply_rule<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> self.apply(child)<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> File "C:\Kivy-1.9.0-py3.4-win32-x64\Python34\lib\site-packages\kivy\lang.py", line 1924, in apply<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> self._apply_rule(widget, rule, rule)<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> File "C:\Kivy-1.9.0-py3.4-win32-x64\Python34\lib\site-packages\kivy\lang.py", line 2038, in _apply_rule<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> self._apply_rule(child, crule, rootrule)<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> File "C:\Kivy-1.9.0-py3.4-win32-x64\Python34\lib\site-packages\kivy\lang.py", line 2038, in _apply_rule<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> self._apply_rule(child, crule, rootrule)<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> File "C:\Kivy-1.9.0-py3.4-win32-x64\Python34\lib\site-packages\kivy\lang.py", line 2035, in _apply_rule<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> child = cls(__no_builder=True)<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> File "C:\SVNProj\Raggio\trunk\hostconsole\gui\mygraph.py", line 127, in __init__<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> self.create_plot()<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> File "C:\SVNProj\Raggio\trunk\hostconsole\gui\mygraph.py", line 224, in create_plot<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> self.add_widget(canvas)<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> File "C:\Kivy-1.9.0-py3.4-win32-x64\Python34\lib\site-packages\kivy\uix\boxlayout.py", line 211, in add_widget<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> widget.bind(<o:p></o:p></span></p>
<p class="MsoNormal" style="background:#FAFAFA"><span style="font-size:10.0pt;font-family:"Courier New";color:black;mso-fareast-language:EN-GB"> AttributeError: 'FigureCanvasAgg' object has no attribute 'bind'<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Can anyone help with that please?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Best regards<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">David<o:p></o:p></p>
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