Re: [Matplotlib-users] Reworked axis('scaled')

[Mark B. <ma...@gm...>]

Helge and others -

I really like Helge's idea to zoom by 20% in Toolbar2 if you click once onl=
y.
Will even try to center it near the click if possible.
Will try to implement a version of her code this week.
Incidentally, I found a bug and an inconsistency in my axis('scaled')
implementation.
The new pylab file on the patches page is fixed.

Mark

On 10/17/05, Helge Avlesen <he...@gm...> wrote:
>
>
>
> On 10/14/05, Mark Bakker <ma...@gm...> wrote:
> > Hello all -
> >
> > I finally found time to fix the axis('scaled') feature.
> > It is now consistent when zooming, as requested.
> > In essence, it works the same as axis('equal'), but fixes the
> > lower-left-hand corner rather than the center of the
> > subplot. When using axis('scaled') the _autoscaleon is
> > set to False, so that axis limits will be fixed when
> > features are added to the figure. You can overwrite this
> > by setting it the regular way (also works for axis('equal'))
> > ax.set_autoscale_on(False).
> >
> > My last modification is a prototype implementation of
> > zooming when two axes are linked. The idea behind this
> > is that when an axis is 'equal' or 'scaled' and another
> > axis is linked to this axis, that when you are zooming and
> > changing the size of the subplot, then the size of the
> > linkes axis should change accordingly. I use this when
> > I am contouring 2D horizontal data and have a vertical
> > cross-section linked to the x-axis of the horizontal plot.
> > When I zoom in on the horizontal plot, the length of the
> > linked axis now gets changes too! Works great, actually,
> > but has been implemented for linked x-axis only for now.
> > It works when zooming in the horizontal data (which
> > has axis 'equal'), but not yet when zooming in the
> > linked vertical cross-section. Still working on it.
>
>
> Hi,
> yes this is a step in the right direction!  IMO it would also be nice wit=
h
> functionality for
> zooming in/out on single clicks with the left and right button, e.g.
> something like the below for backend_bases.py:  (hope it is not wrapped t=
o
> death...)
>
> Helge
>
>
> <pre>
> ...
> def release_zoom(...):
>     ...
>        # single click: 5 pixels is a threshold
>         if abs(x-lastx)<5 or abs(y-lasty)<5:
>
>             lastx, lasty =3D a.transData.inverse_xy_tup( (lastx, lasty) )
>             x, y =3D a.transData.inverse_xy_tup ( (x, y) )
>             Xmin,Xmax=3Da.get_xlim()
>             Ymin,Ymax=3Da.get_ylim()
>
>             if self._button_pressed =3D=3D 1:
>
>                 # zoom in by 20%, make point clicked center
>                 dx=3D(Xmax-Xmin)* 0.8*0.5
>                 dy=3D(Ymax-Ymin)*0.8*0.5
>                 a.set_xlim((x-dx, x+dx))
>                 a.set_ylim((y-dy, y+dy))
>
>             elif self._button_pressed =3D=3D 3:
>
>                 # zoom out by 20%, make point clicked center
>                 dx=3D(Xmax-Xmin)*1.2*0.5
>                 dy=3D(Ymax-Ymin)*1.2*0.5
>                 a.set_xlim((x-dx, x+dx))
>                 a.set_ylim ((y-dy, y+dy))
>
>             self.draw()
>             self._xypress =3D None
>             self._button_pressed =3D=3D None
>
>             self.push_current()
>             self.release(event)
>             return
>
>    # zoom to rect
>   ...
> </pre>
>
>
>
>