Re: [Matplotlib-users] How to blank an area of the canvas?
Jae-Joon Lee wrote: I have added a bbox support for restore_region, but I'm afraid that this feature is not well tested. And I guess what you find is, unfortunately, a bug. While I'll try to push the changes to the svn tomorrow, you may try to monkey-patch with following code. snip Thanks a lot, this seems to basically work. For some reason the bboxes are still restored at slightly the wrong place --- I have to adjust them by one pixel in the y direction, but this is doable. However, while matplotlib does support some animation, I think you 'd better turn to another tool if you need an efficiency, Maybe so. What tool would you recommend for animated plots? Best wishes, -- Brendan Barnwell Do not follow where the path may lead. Go, instead, where there is no path, and leave a trail. --author unknown -- SOLARIS 10 is the OS for Data Centers - provides features such as DTrace, Predictive Self Healing and Award Winning ZFS. Get Solaris 10 NOW http://p.sf.net/sfu/solaris-dev2dev ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] How to blank an area of the canvas?
Brendan Barnwell wrote: I'm trying to find the quickest way to erase a rectangular area of the figure canvas. I tried using canvas.restore_region with the optional bbox argument, but there seems to be some mismatch between the measurement units of the saved buffer object and the currently shown data. For instance, if I have a Text object on my plot, I tried this: bbox = g.text.get_window_extent() canvas.restore_region(background, bbox) . . . but it does not correctly block out the text. (The restored rectangle from the background appears elsewhere on the axes.) How can I convert the buffer coordinates to the coordinates of the the displayed plot? I'm sorry to bump my own post, but I would really appreciate some help with this. I've been wrestling with it for a couple days now, and I cannot figure out how the coordinate system of the saved canvas is related to the axes coordinates. I have found that with bbox.transformed(ax.transData) I can at least get the coordinates scaled to fit on the axes, but they are still offset in position from where the box actually appears on the canvas. I can't figure out how to compute this offset. By playing around with the coordinates manually, for instance, I've found that adjusting x by -52 and y by 21 appears to line up the canvas with the axes, but I can't see where these numbers -52 and 21 would come from. My saved canvas buffer's get_extents() method returns (65, 50, 586, 443), so I thought that the appropriate offsets would be 65 and 50, but that doesn't work. So, what coordinates (x1, y1, x2, y2) do I need to use in canvas.restore_region(savedBuffer, (x1, y1, x2, y2)) in order to restore precisely the area of canvas occupied by a patch drawn at axis coordinates (a1, b1, a2, b2)? Thanks? -- Brendan Barnwell Do not follow where the path may lead. Go, instead, where there is no path, and leave a trail. --author unknown -- SOLARIS 10 is the OS for Data Centers - provides features such as DTrace, Predictive Self Healing and Award Winning ZFS. Get Solaris 10 NOW http://p.sf.net/sfu/solaris-dev2dev ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] How to blank an area of the canvas?
I have added a bbox support for restore_region, but I'm afraid that this feature is not well tested. And I guess what you find is, unfortunately, a bug. While I'll try to push the changes to the svn tomorrow, you may try to monkey-patch with following code. from matplotlib.transforms import Bbox, BboxBase from matplotlib.backends.backend_agg import RendererAgg def restore_region(self, region, bbox=None, xy=None): if bbox is not None or xy is not None: rx, ry, width, height = region.get_extents() if bbox is None: x1, y1, x2, y2 = region.get_extents() elif isinstance(bbox, BboxBase): x1, y1, x2, y2 = bbox.extents else: x1, y1, x2, y2 = bbox if xy is None: ox, oy = rx, ry else: ox, oy = xy self._renderer.restore_region2(region, x1, height-y2+ry, x2, height-y1+ry, ox, oy) else: self._renderer.restore_region(region) RendererAgg.restore_region = restore_region But, again, the code is not well tested and there could be another bug (or even this patch may introduce a new bug). So, see how it works and let know of any problem. However, while matplotlib does support some animation, I think you 'd better turn to another tool if you need an efficiency, Regards, -JJ On Sun, Feb 14, 2010 at 2:18 PM, Brendan Barnwell brenb...@brenbarn.net wrote: Brendan Barnwell wrote: I'm trying to find the quickest way to erase a rectangular area of the figure canvas. I tried using canvas.restore_region with the optional bbox argument, but there seems to be some mismatch between the measurement units of the saved buffer object and the currently shown data. For instance, if I have a Text object on my plot, I tried this: bbox = g.text.get_window_extent() canvas.restore_region(background, bbox) . . . but it does not correctly block out the text. (The restored rectangle from the background appears elsewhere on the axes.) How can I convert the buffer coordinates to the coordinates of the the displayed plot? I'm sorry to bump my own post, but I would really appreciate some help with this. I've been wrestling with it for a couple days now, and I cannot figure out how the coordinate system of the saved canvas is related to the axes coordinates. I have found that with bbox.transformed(ax.transData) I can at least get the coordinates scaled to fit on the axes, but they are still offset in position from where the box actually appears on the canvas. I can't figure out how to compute this offset. By playing around with the coordinates manually, for instance, I've found that adjusting x by -52 and y by 21 appears to line up the canvas with the axes, but I can't see where these numbers -52 and 21 would come from. My saved canvas buffer's get_extents() method returns (65, 50, 586, 443), so I thought that the appropriate offsets would be 65 and 50, but that doesn't work. So, what coordinates (x1, y1, x2, y2) do I need to use in canvas.restore_region(savedBuffer, (x1, y1, x2, y2)) in order to restore precisely the area of canvas occupied by a patch drawn at axis coordinates (a1, b1, a2, b2)? Thanks? -- Brendan Barnwell Do not follow where the path may lead. Go, instead, where there is no path, and leave a trail. --author unknown -- SOLARIS 10 is the OS for Data Centers - provides features such as DTrace, Predictive Self Healing and Award Winning ZFS. Get Solaris 10 NOW http://p.sf.net/sfu/solaris-dev2dev ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users -- SOLARIS 10 is the OS for Data Centers - provides features such as DTrace, Predictive Self Healing and Award Winning ZFS. Get Solaris 10 NOW http://p.sf.net/sfu/solaris-dev2dev ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
[Matplotlib-users] How to blank an area of the canvas?
I'm trying to find the quickest way to erase a rectangular area of the figure canvas. I tried using canvas.restore_region with the optional bbox argument, but there seems to be some mismatch between the measurement units of the saved buffer object and the currently shown data. For instance, if I have a Text object on my plot, I tried this: bbox = g.text.get_window_extent() canvas.restore_region(background, bbox) . . . but it does not correctly block out the text. (The restored rectangle from the background appears elsewhere on the axes.) How can I convert the buffer coordinates to the coordinates of the the displayed plot? I also tried creating a patch with the same bounds as the text bbox and adding it to the axes, but this seems to have no effect. Do I have to do something besides ax.draw_artist(mypatch) to get it to draw? This is part of the same thing I posted about a few days ago with trying to do an animation with many moving parts. Are there any examples of animations which do not involve restoring the entire background with each draw, but rather individually erasing individual elements in the plot and redrawing them elsewhere? That's what I'm trying to do here. Thanks, -- Brendan Barnwell Do not follow where the path may lead. Go, instead, where there is no path, and leave a trail. --author unknown -- SOLARIS 10 is the OS for Data Centers - provides features such as DTrace, Predictive Self Healing and Award Winning ZFS. Get Solaris 10 NOW http://p.sf.net/sfu/solaris-dev2dev ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
