Eric Firing wrote: > Ryan May wrote: >> Hi, >> >> I'll continue my current flood of emails to the list. :) I'm finally >> getting back to my work on Skew-T plots, and I have a semi-working >> implementation (attached.) It runs, and as is, plots up some of the >> grid, with the x-value grid lines skewed 45 degrees to the right (as >> they should be.) The problem is as you resize the plot horizontally, >> some weird things happen. First, some of the lines that start >> overlaid end up separating as you expand the plot. The difference is >> between what is added using ax.plot and what is added using >> ax.vlines. The former adds Line2D objects while the latter adds a >> LineCollection which is holding path objects. I'm really not sure >> what's going on there. I'm not done checking it out yet, but I'm >> curious if anyone has any ideas off the top of their head. >> >> The second issue, which is more pressing, is when you resize >> vertically, the axes limits of the plot don't change (good), but >> unfortunately the lines don't stay connected to their lower >> y-coordinate in data space (bad). I'm really needing to draw things >> in a coordinate system that's independant of the data scale but also >> doesn't depend on the aspect ratio of the axes, so that I can get >> lines (and data plots) where the x gridlines are always at a 45 degree >> angle and the lower Y-value point stays fixed. By problem right now >> is that while I can find the lower left corner in pixel space and use >> that to do the proper adjustments, this changes when you resize. This >> changing is especially important in the y-direction. What I need is >> either of: >> >> 1) Axes space adjusted for aspect ratio (and updated with resizes) >> 2) Pixel space relative to some corner of the axes >> >> Or something similar that I don't know about. Any thoughts, or do I >> just need to come up with some magical combination of transforms that >> works? You can see what I have so far in my attached file. >> > > Ryan, based only on your description of the problems, and of what you > need, I think the answer, or at least part of it, may be in good old > quiver. Look at the way the transform is being generated depending on > the units chosen, and note that preserving a specified angle on the page > is part of it. Also note that the transform has to be regenerated on > resize events, so a custom draw method is required.
I'll take a look and see what I come up with, thanks for the tip. > > (Mike D. translated my original quiver code to use his transforms > framework.) > > It seems like there should be an easier-to-use and more general way to > do these sorts of things, and maybe there is--or maybe it can be ginned up. That's kind of what I was thinking and hoping. I would think this would be useful in a lot of places, especially where orientation relative to the screen is important, since that's not preserved when the axes are resized. > > This reminds me of a thread a long time ago regarding adding hooks so > that classes could register methods to be executed before their artists > are rendered but after things like window and axes sizes have been > determined. Yeah it seems like this comes up a lot. What would be nice though, instead of hooks, would be to fetch the necessary values when the transform is actually needed, instead of being notified of when the transform itself needs to be regenerated. Notifications would seem to add needless boilerplate code. Ryan -- Ryan May Graduate Research Assistant School of Meteorology University of Oklahoma ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Matplotlib-devel mailing list Matplotlib-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
