Hello all, I've been working on some interactive graphs and have run into several problems with the pick_event feature: (1) If a Figure Legend is made draggable() and then dropped onto an AxesSubplot, it can no longer be dragged (2) Any lines associated with the left axis of a twinx() subplot are unable to be picked (3) Hidden lines can be picked (seems like an undesirable feature). Try picking on the top subplot at y=1 for a hidden line.
I know #2 has <a href="http://old.nabble.com/onpick-on-a-2-y-plot-%28-via-twinx%28%29-%29-seems-to-only-allow-picking-of-second-axes%27s-artists-td25049128.html";>caused problems for others</a>, with less than elegant solutions given. Here's the code showing what is currently broken (as of v1.0.0): #!/usr/bin/env python import matplotlib as mpl import pylab # <-- Insert code to fix problem here def on_pick(event): if isinstance(event.artist, mpl.legend.Legend): print 'Picked Legend' else: print 'Picked', event.artist.get_label(), event.ind fig = pylab.figure() ax = fig.add_subplot(211) ax2 = fig.add_subplot(212) ax3 = ax2.twinx() # Top subplot ax.plot(range(10), range(10), c='r', marker='^', picker=5, label='Ramp') line, = ax.plot(range(10), [1]*10, c='k', marker='o', picker=5, label='Hidden') line.set_visible(False) # Bottom subplot legn_handles = [] legn_labels = [] line = ax2.plot(range(10), [1,3,1,3,0,3,1,3,1,3], c='b', marker='o', picker=5, label='Teeth') legn_handles.append(line) legn_labels.append('Teeth') ax2.set_ylim(0, 4) ax2.set_ylabel('Left side', color='b') line = ax3.plot(range(10), [1,1,1,1,4,4,4,4,4,4], c='m', marker='.', picker=5, label='Shelf') legn_handles.append(line) legn_labels.append('Shelf') ax3.set_ylim(0, 5) ax3.set_ylabel('Right side', color='m') # Subplot Legend for top plot legn = ax.legend() legn.draggable() # Figure Legend legn = fig.legend(legn_handles, legn_labels, 'lower right') legn.draggable() fig.canvas.mpl_connect('pick_event', on_pick) pylab.show() # -------------------------------------------------------------------------------------------- I've found a decent workaround, but it involves some very fundamental changes to the way picking is resolved in the Figure and Axes classes. If you add the following code to the spot indicated for the fix, everything works correctly. # Fix for pick_event problems def axes_pick(self, *args): if len(args)>1: raise DeprecationWarning('New pick API implemented -- ' 'see API_CHANGES in the src distribution') mouseevent = args[0] if not self.in_axes(mouseevent): return for a in self.get_children(): if not a.get_visible(): continue a.pick(mouseevent) mpl.axes.Axes.pick = axes_pick def figure_pick(self, mouseevent): for a in self.get_children(): if not a.get_visible(): continue a.pick(mouseevent) mpl.figure.Figure.pick = figure_pick To compare the differences, you need to look at the artist.Artist.pick() method. It only calls pick() for children whose axes==mouseevent.inaxes or when inaxes is None (to handle the Legend). But this fails when the Legend is dragged over a Subplot (inaxes no longer None), causing bug #1. Also, mouseevent.inaxes only contains a single axes instance, which causes a failure for overlapping twinx() axes, hence bug #2. And of course there is no check for hidden artists (#3). My change calls pick() for every child of the Figure or Subplot, but then has the Subplot check whether the mouseevent is in its own axes space. This seems to fix all the problems, but could potentially cause new bugs. Any thoughts? I'm new to the mailing list, so I'm not sure how patches get applied and how much testing needs to be done for a change like this. Thanks, Jim ------------------------------------------------------------------------------ Free Software Download: Index, Search & Analyze Logs and other IT data in Real-Time with Splunk. Collect, index and harness all the fast moving IT data generated by your applications, servers and devices whether physical, virtual or in the cloud. Deliver compliance at lower cost and gain new business insights. http://p.sf.net/sfu/splunk-dev2dev _______________________________________________ Matplotlib-devel mailing list Matplotlib-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
