[Matplotlib-users] Backend neutral idle event won't repeat
Hi,
I'm writing a script to plot data being read from a serial connection in
real time. I'm trying to use an idle_event callback to continually read the
incoming data and plot it. The problem is that the callback is only getting
invoked once. I found this page:
http://www.scipy.org/Cookbook/Matplotlib/Animations, which suggests using
backend-specific stuff. This is intended to be a quick-and-dirty thing
though so I was really hoping to avoid that. Here's my code:
def OnIdle(event):
global xData
global yData
data = ReadSerialData()
if data != None:
yData.append(data)
if len(yData) > GRAPH_WINDOW_SIZE:
del yData[0]
else:
xData.append(len(xData))
line.set_xdata(xData)
line.set_ydata(yData)
pylab.draw()
# end if data != None
# end OnIdle
if __name__ == '__main__':
pylab.ion()
fig = pylab.figure()
ax = fig.add_subplot(1,1,1)
line = ax.add_line(pylab.Line2D([], []))
ax.set_ylim(0, 100)
ax.set_xlim(0, GRAPH_WINDOW_SIZE)
fig.canvas.mpl_connect('idle_event', OnIdle)
pylab.show()
# end __name__ == '__main__'
Oh btw, I'm positive that ReadSerialData is not blocking and that it's
making it through the whole idle handler. I'm running on 64 bit Linux with
Python 2.6. According to --verbose-helpful, I'm using matplotlib version
0.98.5.2 and GTKAgg version 2.14.1. Am I doing something wrong or do I
really need to go backend-specific?
Thanks,
Mark
--
Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day
trial. Simplify your report design, integration and deployment - and focus on
what you do best, core application coding. Discover what's new with
Crystal Reports now. http://p.sf.net/sfu/bobj-july___
Matplotlib-users mailing list
Matplotlib-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Backend neutral idle event won't repeat
Thanks for the reply John. Not quite the answer I was looking for though ;) I tried your suggestion of returning True but it didn't solve the problem. Oh well, not the end of the world. Being a die-hard KDE user, I started trying to get things working with Qt. I got my animation working but thus far haven't been able to catch key press events. My guess is that I'm just missing something about how it's supposed to be done so I'll probably figure it out. Thanks again, Mark On Sun, Aug 2, 2009 at 9:17 AM, John Hunter wrote: > On Sun, Aug 2, 2009 at 8:08 AM, John Hunter wrote: > > > Wriing a GUI neutal idle event handler is not easy -- I've spent some > > time on it but crashed and burned on tk -- but my guess is that the > > problem you are having in your code is that GTK expects you to return > > True is you want the func to be called again. As soon as you return > > False the event handler is terminated. You return nothing, which is > > None, which is False. A simple "return True" may cure what ails you > > vis-a-vis gtk. But pylab animation is not supported, so I suggest > > that you code to your GUI of choice for animation until we get a > > proper GUI neutral animation event API. > > I should phrase this last bit differently: I would like to support > this, and spent a fair amount of time trying to get this working > properly across backends. I think it *does* work on GTK and WX. I > encountered some problems in tkagg: since tk does not have a native > idle event loop that I could wrap, I tried to use python threading to > implement it, and ran into problems with cross thread signal handling > (including losing CTRL-C and some strange on-exit behavior) so > commented out the code, and have not attempted qt or macosx. I think > it would be great if we could abstract the idle handler and timeout > handler across the GUIs so that mpl animation would be easier, but to > date this has eluded me. So in the meantime, I would stick to the API > of the GUI of your choice until we can get proper support for this as > an mpl event. > > JDH > -- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Backend neutral idle event won't repeat
On Mon, Aug 3, 2009 at 1:01 PM, Christopher Barker wrote: > John Hunter wrote: > >> Wriing a GUI neutal idle event handler is not easy -- I've spent some > >> time on it but crashed and burned on tk > > > I think > > it would be great if we could abstract the idle handler and timeout > > handler across the GUIs so that mpl animation would be easier, but to > > date this has eluded me. > > Maybe getting away from the Idle event approach would be the way to go. > I've done a lot of (non-MPL) wx work, including animations, and NEVER > found a use for the idle event. For animation work in wx, using a > wx.Timer, and often a call to wx.Yield seems to generally be the way to > go. Perhaps this same approach could be done on the other back ends as > well. > > As for idle events, I've found them to be useless because you get lots > of them when you don't need it, and may not get them when you do. In wx > at least, an Idle event is triggered when the event loop _becomes_ > empty. That means that when the user is moving the mouse and there is no > mouse_move event handler, you get this huge string of idle events. > However, if the user is doing nothing for a bit, you get one event, then > nothing until the user does something again. > > I can see the appeal of an Idle event -- there are all sorts of things > you might want to do when the app is "idle", but the reality is that > what you really want to know is when the app is _going to be_ idle for a > bit, and there is no way to know that (at least not without Guido's time > machine, anyway...). > > I've lost track of what problems you're trying to solve with idle > events, but maybe an abstraction of a timer system would be a more > robust approach, for animations, anyway. > > -Chris > I think that's a fantastic idea, especially if you can go abstract and make it work for all the backends. I've lost track of what problems you're trying to solve with idle events, > but maybe an abstraction of a timer system would be a more robust approach, > for animations, anyway. > If you're referring to my problem, I need to read data from a serial connection which then drives an animated graph. Going as fast as possible is fine but honestly, it's overkill. Strictly using timers would work in both situations. -Mark -- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Windows 64 bit support for matplotlib?
On Mon, Aug 3, 2009 at 3:24 PM, Clem Wang wrote: > Being a new Windows user, there's much that I don't understand... (please > no flaming here...) > > I'm running Windows 7 with a 64 bit OS. When I try to install: > matplotlib-0.98.5.3.win32-py2.6 > > I get this error message: > Python version 2.6 required, which was not found in the registry. > > > However, that is not true because Python 2.6 (64 bit) is in fact installed. > > I believe the actual problem is due to the fact I'm trying to install the > 32 bit library and there is no 64 bit library version of matplotlib. > > The reason I believe that this is my problem, is I tried to install the 32 > bit numpy library and I got the exact same message, but when I tried to > install the 64amd version of the numpy library: > > numpy-1.3.0b1.win-amd64-py2.6 > > The install is successful. > > So, my question is, are there plans to support Matplotlib on Windows 64 bit > machines? > > Thanks! > > -- > Clem Wang > > > > -- > Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day > trial. Simplify your report design, integration and deployment - and focus > on > what you do best, core application coding. Discover what's new with > Crystal Reports now. http://p.sf.net/sfu/bobj-july > ___ > Matplotlib-users mailing list > Matplotlib-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/matplotlib-users > > I have no idea about 64 bit matplotlib, but have you tried installing a 32 bit Python? -Mark -- Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
