Re: [Matplotlib-users] stuck after a mpl_connect - how to disconnect and go on

Hi Eric,

On 23/08/07, Eric Emsellem <ems...@ob...> wrote:
> Hi
>
> sorry to post this again but all my attempts to solve the matplotlib
> problem below failed and I desperately need this to progress.
>
> I would like to use mpl_connect and disconnect to examine a series of 2d
> arrays in turn (with a "for" loop), one after the other:
>
> ==> at each iteration I'd like to be able to use the left mouse button
> to evaluate the sum of all x,y coordinates I select by (right) clicking
> somewhere in the present array, and then switch to the next 2d data
> array after I hit the right mouse button (button==3). I have no clue how
> to do this and the program I wrote so far is just hanging there and does
> nothing. Didn't see anything like this in the archive.
>
> Any way to get out of this? Thanks for your help.

As a general rule of thumb, if you're using a loop like while
newoffset.stay: pass, then you're doing something wrong. This will
take control of all execution and let nothing else happen. You have to
do the control by switching between functions. Here's a modification
to your code that I think does what you want:

import numpy as n
import pylab as p

class offset:
    def __init__(self, parent) :
        self.parent = parent
        self.xc = 0.
        self.yc = 0.
        self.stay = 1

    def on_click(self, event) :
        if event.button == 1:
            if event.inaxes is not None:
                print "Adding point %d, %d" % (event.xdata, event.ydata)
                self.xc += event.xdata
                self.yc += event.ydata
        elif event.button == 3:
            print "Switching data"
            self.parent.show_next()

class displayer:
    def __init__(self):
        self.i = 0
        self.alldata = [n.random.rand(10,10) for x in xrange(3)]
        self.newoffset = offset(self)
        self.binding = p.connect('button_press_event', self.newoffset.on_click)
        self.show_next()

    def show_next(self):
        if self.i < len(self.alldata):
            p.imshow(self.alldata[self.i])
            self.i += 1
        else:
            p.disconnect(self.binding)
            print self.newoffset.xc, self.newoffset.yc

I hope that helps you see the concept.

Angus.
-- 
AJC McMorland, PhD Student
Physiology, University of Auckland