matplotlib-devel Mailing List for matplotlib

On Thu, Jun 14, 2012 at 4:12 PM, Benjamin Root <ben...@ou...> wrote:
>
>
> On Thu, Jun 14, 2012 at 11:08 AM, tcb <the...@gm...> wrote:
>
>> Hi,
>>
>> I'm trying to plot a grid of images with no spaces in between them and I
>> have problems with the snapping. The grid is computed in data coordinates
>> and the positions of the images are determined by the extents parameter
>>
>> ax.imshow(read_png(filename), extent=extent, snap=True)
>>
>>
>> The images and extents are always the same size and each image starts
>> where the last finished
>>
>> (x0, x0+dx, y0, y0+dy)
>> (x0+dx, x0+2*dx, y0, y0+dy)
>> etc...
>>
>>
>> but it seems something happens in the backend (both QT4 and GTKAgg) and
>> pixel seams are visible between the images at various zoom levels.
>>
>> It seems the ImageGrid was developed to fix this kind of problem, but I'm
>> not sure I can adapt my plot to use ImageGrid. I want to draw stuff over my
>> images and I need to position them in data coordinates.
>>
>> I've tried the snap=True parameter to imshow and it doesn't seem to
>> affect the output.
>>
>> Does anyone have a simple solution to this problem which eliminates the
>> seams?
>>
>> thanks,
>>
>>
>>
> Could you try out the latest version of matplotlib from the master
> branch? There have been some work in this area in the past few months. I
> don't know if any of that work went into the recently announced v1.1.1-rc2.
>
> Ben Root
>
>
hi,
I'm using the latest version from git.
Any idea what patches are part of that work? or even which
classes/functions were touched?
thanks,

On Thu, Jun 14, 2012 at 11:08 AM, tcb <the...@gm...> wrote:
> Hi,
>
> I'm trying to plot a grid of images with no spaces in between them and I
> have problems with the snapping. The grid is computed in data coordinates
> and the positions of the images are determined by the extents parameter
>
> ax.imshow(read_png(filename), extent=extent, snap=True)
>
>
> The images and extents are always the same size and each image starts
> where the last finished
>
> (x0, x0+dx, y0, y0+dy)
> (x0+dx, x0+2*dx, y0, y0+dy)
> etc...
>
>
> but it seems something happens in the backend (both QT4 and GTKAgg) and
> pixel seams are visible between the images at various zoom levels.
>
> It seems the ImageGrid was developed to fix this kind of problem, but I'm
> not sure I can adapt my plot to use ImageGrid. I want to draw stuff over my
> images and I need to position them in data coordinates.
>
> I've tried the snap=True parameter to imshow and it doesn't seem to affect
> the output.
>
> Does anyone have a simple solution to this problem which eliminates the
> seams?
>
> thanks,
>
>
>
Could you try out the latest version of matplotlib from the master branch?
There have been some work in this area in the past few months. I don't
know if any of that work went into the recently announced v1.1.1-rc2.
Ben Root

Hi,
I'm trying to plot a grid of images with no spaces in between them and I
have problems with the snapping. The grid is computed in data coordinates
and the positions of the images are determined by the extents parameter
ax.imshow(read_png(filename), extent=extent, snap=True)
The images and extents are always the same size and each image starts where
the last finished
(x0, x0+dx, y0, y0+dy)
(x0+dx, x0+2*dx, y0, y0+dy)
etc...
but it seems something happens in the backend (both QT4 and GTKAgg) and
pixel seams are visible between the images at various zoom levels.
It seems the ImageGrid was developed to fix this kind of problem, but I'm
not sure I can adapt my plot to use ImageGrid. I want to draw stuff over my
images and I need to position them in data coordinates.
I've tried the snap=True parameter to imshow and it doesn't seem to affect
the output.
Does anyone have a simple solution to this problem which eliminates the
seams?
thanks,

I don't think this has anything to do with matplotlib, but instead just 
with pygobject (or perhaps just gtk itself) on Fedora 17.
I suspect that this fedora bug is responsible:
https://bugzilla.redhat.com/show_bug.cgi?id=790053
Importing gtk is enough to produce this warning:
In [1]: import gtk
** (process:15013): WARNING **: Trying to register gtype 
'GMountMountFlags' as enum when in fact it is of type 'GFlags'
** (process:15013): WARNING **: Trying to register gtype 
'GDriveStartFlags' as enum when in fact it is of type 'GFlags'
** (process:15013): WARNING **: Trying to register gtype 
'GSocketMsgFlags' as enum when in fact it is of type 'GFlags'
Mike
On 06/13/2012 05:40 PM, Neal Becker wrote:
> Since installing this on fedora f17 x86_64, I see this warning:
>
> ipython -pylab
> ...
>
> ** (process:26729): WARNING **: Trying to register gtype 'GMountMountFlags' as
> enum when in fact it is of type 'GFlags'
>
> ** (process:26729): WARNING **: Trying to register gtype 'GDriveStartFlags' as
> enum when in fact it is of type 'GFlags'
>
> ** (process:26729): WARNING **: Trying to register gtype 'GSocketMsgFlags' as
> enum when in fact it is of type 'GFlags'
>
> Welcome to pylab, a matplotlib-based Python environment [backend: GTKAgg].
> For more information, type 'help(pylab)'.
>
>
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