Re: [Matplotlib-users] Matplotlib + py3 + gtk3

SourceForge Headquarters 1320 Columbia Street Suite 310 San Diego, CA 92101 +1 (858) 422-6466

Thanks.  I'd definitely consider this a bug this.  Would you mind 
creating an issue or pull request on github.com/matplotlib/matplotlib so 
it doesn't get lost?

Mike

On 03/01/2014 05:42 PM, Jon Roadley-Battin wrote:
> >On 02/27/2014 06:58 PM, Jon Roadley-Battin wrote:
> >> Good evening,
> >>
> >> I am at present migrating an application of mine from py27+pygtk (with
> >> mpl) to py33+pygobject (gtk3)
> >>
> >> Unfortunately I am unable to use
> >>
> >> from  matplotlib.backends.backend_gtk3agg  import 
>  FigureCanvasGTK3Agg  as  FigureCanvas
> >> from  matplotlib.backends.backend_gtk3  import 
>  NavigationToolbar2GTK3  as  NavigationToolbar
> >>
> >> Which is is on the examples (
> >> 
> http://matplotlib.org/examples/user_interfaces/embedding_in_gtk3_panzoom.html
> >> ) but is also the logical translation from what I presently have.
> >> This falls fowl of the cairo issue
> >>
> >> What I am having to use is backend_gtk3cairo. However this is being
> >> triggered
> >>
> >>  raise ValueError("The Cairo backend can not draw paths longer than
> >> 18980 points.")
> >>
> >> I am generally plotting 7 x-y plots with upto 30,000 points.
> >> Now for now I have commented this out from my local install, is there
> >> a better/preferred/recommended alternative?
> >
> >This was put in there because cairo had (at least at the time) a hard
> >coded limit on path size, and getting a Python exception was IMHO
> >preferable to segfaulting and having the process go away.  Are you
> >saying that when you comment it out, it's currently working?  It may be
> >that cairo has fixed this limit in the intervening years. Can you
> >provide a simple, standalone example that reproduces the error?
>
>
> Using python33 & pygi-aio-3.10.2-win32_rev18 (to provide pygobject for 
> windows:)
> Using: 
> http://matplotlib.org/examples/user_interfaces/embedding_in_gtk3_panzoom.html 
> as the baseline provides the following error:
>
> <  File 
> "c:\Python33\lib\site-packages\matplotlib\backends\backend_gtk3agg.py", line 
> 52, in on_draw_event
>     buf, cairo.FORMAT_ARGB32, width, height)
> NotImplementedError: Surface.create_for_data: Not Implemented yet.
>
>
> This has been mentioned a few times across the ml
>
> Modifying the example to use backend_gtk3cairo
>
> from matplotlib.backends.backend_gtk3cairo import 
> FigureCanvasGTK3Cairo as FigureCanvas
> from matplotlib.backends.backend_gtk3 import NavigationToolbar2GTK3 as 
> NavigationToolbar
>
>
> Now the example runs and plots a nice sinewave (as expected). Modify 
> the script to plot 7 waveforms, 100pts
>
> ##############################################################################################################
> #!/usr/bin/env python3
> """
> demonstrate NavigationToolbar with GTK3 accessed via pygobject
> """
>
> from gi.repository import Gtk
>
> from matplotlib.figure import Figure
> import numpy as np
> from matplotlib.backends.backend_gtk3cairo import 
> FigureCanvasGTK3Cairo as FigureCanvas
> from matplotlib.backends.backend_gtk3 import NavigationToolbar2GTK3 as 
> NavigationToolbar
>
>
> win = Gtk.Window()
> win.connect("delete-event", Gtk.main_quit )
> win.set_default_size(400,300)
> win.set_title("Embedding in GTK")
>
> fig = Figure(figsize=(5,4), dpi=100)
> plt = fig.add_subplot(1,1,1)
>
> t = np.arange(0,2*np.pi,2*np.pi/100)
> a = np.sin(t + 0*(2*np.pi/7))
> b = np.sin(t + 1*(2*np.pi/7))
> c = np.sin(t + 2*(2*np.pi/7))
> d = np.sin(t + 3*(2*np.pi/7))
> e = np.sin(t + 4*(2*np.pi/7))
> f = np.sin(t + 5*(2*np.pi/7))
> g = np.sin(t + 6*(2*np.pi/7))
> plt.plot(t,a)
> plt.plot(t,b)
> plt.plot(t,c)
> plt.plot(t,d)
> plt.plot(t,e)
> plt.plot(t,f)
> plt.plot(t,g)
>
> vbox = Gtk.VBox()
> win.add(vbox)
>
> # Add canvas to vbox
> canvas = FigureCanvas(fig)  # a Gtk.DrawingArea
> vbox.pack_start(canvas, True, True, 0)
>
> # Create toolbar
> toolbar = NavigationToolbar(canvas, win)
> vbox.pack_start(toolbar, False, False, 0)
>
> win.show_all()
> Gtk.main()
> ####################################################################################################################
>
> This works, its only 100pts for 7 scatters so nothing unexpected.
> Modify the arange to create a time array of 30,000 pts.
>
> t = np.arange(0,2*np.pi,2*np.pi/30000)
>
>
>   File 
> "c:\Python33\lib\site-packages\matplotlib\backends\backend_cairo.py", 
> line 143, in draw_path
>     raise ValueError("The Cairo backend can not draw paths longer than 
> 18980 points.")
> ValueError: The Cairo backend can not draw paths longer than 18980 points.
>
>
> The already mentioned raise to protect against a segfault.
> Edit backend_cairo to comment out the check:
>
>
>     def draw_path(self, gc, path, transform, rgbFace=None):
>         #if len(path.vertices) > 18980:
>         #    raise ValueError("The Cairo backend can not draw paths 
> longer than 18980 points.")
>
>         ctx = gc.ctx
>
>
>
> 7channel, 30,000 pts each is plotted just fine. Zoom rectangle is slow 
> to render, but this is true for 100pts (so more a gtk3 thing than a 
> cairo and multiple points thing)
>
> Final script:
>
>
>
> #######################################################################################################################
> #!/usr/bin/env python3
> """
> demonstrate NavigationToolbar with GTK3 accessed via pygobject
> """
>
> from gi.repository import Gtk
>
> from matplotlib.figure import Figure
> import numpy as np
> from matplotlib.backends.backend_gtk3cairo import 
> FigureCanvasGTK3Cairo as FigureCanvas   #changed to use gtk3cairo
> from matplotlib.backends.backend_gtk3 import NavigationToolbar2GTK3 as 
> NavigationToolbar
>
>
> win = Gtk.Window()
> win.connect("delete-event", Gtk.main_quit )
> win.set_default_size(400,300)
> win.set_title("Embedding in GTK")
>
> fig = Figure(figsize=(5,4), dpi=100)
> plt = fig.add_subplot(1,1,1)
>
> t = np.arange(0,2*np.pi,2*np.pi/30000)                # 30,000 pt time 
> array for 7 signals
> a = np.sin(t + 0*(2*np.pi/7))
> b = np.sin(t + 1*(2*np.pi/7))
> c = np.sin(t + 2*(2*np.pi/7))
> d = np.sin(t + 3*(2*np.pi/7))
> e = np.sin(t + 4*(2*np.pi/7))
> f = np.sin(t + 5*(2*np.pi/7))
> g = np.sin(t + 6*(2*np.pi/7))
> plt.plot(t,a)
> plt.plot(t,b)
> plt.plot(t,c)
> plt.plot(t,d)
> plt.plot(t,e)
> plt.plot(t,f)
> plt.plot(t,g)
>
> vbox = Gtk.VBox()
> win.add(vbox)
>
> # Add canvas to vbox
> canvas = FigureCanvas(fig)  # a Gtk.DrawingArea
> vbox.pack_start(canvas, True, True, 0)
>
> # Create toolbar
> toolbar = NavigationToolbar(canvas, win)
> vbox.pack_start(toolbar, False, False, 0)
>
> win.show_all()
> Gtk.main()
> ######################################################################################################################
>
>
>
> Hope this helps. or is useful
>
> JonRB
>
>
>
> ------------------------------------------------------------------------------
> Flow-based real-time traffic analytics software. Cisco certified tool.
> Monitor traffic, SLAs, QoS, Medianet, WAAS etc. with NetFlow Analyzer
> Customize your own dashboards, set traffic alerts and generate reports.
> Network behavioral analysis & security monitoring. All-in-one tool.
> http://pubads.g.doubleclick.net/gampad/clk?id=126839071&iu=/4140/ostg.clktrk
>
>
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users

-- 
                    _
|\/|o _|_  _. _ | | \.__  __|__|_|_  _  _ ._ _
|  ||(_| |(_|(/_| |_/|(_)(/_|_ |_|_)(_)(_)| | |

http://www.droettboom.com