Jeff, I sent that last message a little too quickly. Now I see that pyproj really is trying to ensure a copy--that is what the comments and docstring say--so I will simply try to find and fix the bug, the particular case in which a copy is not being made.
Eric Eric Firing wrote: > Jeff, > > I ran into a major bug that I think results from a fairly deep-seated > gotcha in basemap. The problem lies with the in-place transformation of > lon,lat in the proj library. This is not an inherent problem in itself; > the trouble comes because sometimes the data get copied along the way > from the basemap interface into proj, and sometimes they don't. When > they don't get copied, rotate_vector breaks, because the input lon,lat > variables are transformed in place, and then they are no longer lon and > lat when they need to be reused as such. > > This could be fixed with a copy in rotate_vector, but I recommend that > instead it be fixed by guaranteeing that there is a copy at a much lower > level, probably in the pyproj Proj.__call__ method, and if not there, > then in the basemap.__call__ method. I am not sure what all the effects > might be, though--is anything relying on in-place calculation at that level? > > The reason for recommending the low-level copy is that if > basemap.__call__ continues to behave as it does, sometimes obliterating > its input arguments via the in-place operation and sometimes not, it > will continue to cause horrible surprises. I think that the overhead of > a single copy would be a small price to pay to eliminate such surprises. > > If there is a need to preserve the in-place option, then perhaps it > could be accessed through a different interface. Let __call__ guarantee > that its input arguments are preserved, and have a "transform" method > that minimizes copying. > > Eric > > ------------------------------------------------------------------------- > This SF.net email is sponsored by the 2008 JavaOne(SM) Conference > Don't miss this year's exciting event. There's still time to save $100. > Use priority code J8TL2D2. > http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone > _______________________________________________ > Matplotlib-devel mailing list > Matplotlib-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/matplotlib-devel ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ Matplotlib-devel mailing list Matplotlib-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
