matplotlib-devel Mailing List for matplotlib

When using unitized data any call to 'set_xlim' or 'set_ylim' will reset any user specified labels or tickers for a given axis and
replace it with the values specified via the unitized data 'axisinfo'

See the following for an example:

###########################################
from basic_units import cm, inch
from pylab import figure, show
import numpy

cms = cm *numpy.arange(0, 10, 2)

fig = figure()

ax1 = fig.add_subplot(2,2,1)
ax1.plot(cms, cms)

ax2 = fig.add_subplot(2,2,2)
ax2.plot(cms, cms, xunits=cm, yunits=inch)

ax3 = fig.add_subplot(2,2,3)
ax3.plot(cms, cms, xunits=inch, yunits=cm)
ax3.set_xlabel( "My Label" )
ax3.set_xlim(3, 6)  # scalars are interpreted in current units

# Since we call set_xlim with unitized data, the label will be reset.
ax4 = fig.add_subplot(2,2,4)
ax4.plot(cms, cms, xunits=inch, yunits=inch)
ax4.set_xlabel( "My Label" )
ax4.set_xlim(3*cm, 6*cm) # cm are converted to inches

show()
###########################################

--James Evans

On Fri, Feb 08, 2008 at 08:15:20AM +0100, Gael Varoquaux wrote:
> On Thu, Feb 07, 2008 at 11:31:11AM -0500, Paul Kienzle wrote:
> > There are two ways to do this in wx.  
> 
> > One is to use eventloop.Dispatch() which waits until the next available
> > event:
> 
> >   [...]
> 
> > The other is to trigger a loop.Exit() from the click callback.  
> 
> >   [...]
> 
> Very nice. I am impressed. We need to find a way of doing the same in
> other toolkits. Way can however change the function call flush_event to
> give it an "until" callback (and maybe rename it to
> "wait_interactively"), and move the busy waiting code in the
> backend-dependant part of the code. That way we can remove it backend
> after backend.

Having played with both "flush_until" and "start/stop"  I have to say I
prefer the start/stop interface.  It removes the need for users to share
a 'done' variable between the callback and the caller and the need to 
create a dummy lambda:done function.  Also, it is a better match to
the semantics of wx/gtk/qt (see below).

I don't like the names start_event_loop/stop_event_loop, but couldn't 
think of anything better.  How about: gui_wait/end_wait?


    - Paul

-----

Proposed generic implementation based on flush_event and sleep, to be
put into CanvasBase:

    def gui_wait(self, timeout=0):
        """Run the event loop."""
        if timeout == 0: timeout = npy.inf
        timestep = 0.01
        counter = 0
        self._waiting = True
        while self._waiting and counter*timestep < timeout:
            self.flush_events()
            time.sleep(timestep)
            counter += 1

    def end_wait(self):
        """Stop the event loop."""
        self._waiting = False

Suggested implementation for backend_gtk (untested!!!):

    def gui_wait(self, timeout=0):
        """Run the gtk event loop."""
        # TODO: call self.end_wait() on window close
        self._waiting = True
        if timeout > 0:
            timer = gtk.gobject.timeout_add(timeout,self._onTimer)
        gtk.main()
        self._waiting = False
        gobject.source_remove(timer)

    def _onTimer(self):
        self.end_wait()
        return False

    def end_wait(self):
        """Stop the gtk event loop."""
        if self._waiting: gtk.main_quit()

On Thu, Feb 07, 2008 at 11:31:11AM -0500, Paul Kienzle wrote:
> There are two ways to do this in wx.  

> One is to use eventloop.Dispatch() which waits until the next available
> event:

>   [...]

> The other is to trigger a loop.Exit() from the click callback.  

>   [...]

Very nice. I am impressed. We need to find a way of doing the same in
other toolkits. Way can however change the function call flush_event to
give it an "until" callback (and maybe rename it to
"wait_interactively"), and move the busy waiting code in the
backend-dependant part of the code. That way we can remove it backend
after backend.

I can contribute a bit to this refactoring, but give me a couple of weeks
before.

Cheers,

Gaël