Hello Ian, Thank you for your second proposition ; I find it very interesting in fact. (But beware that, as I do not feel able to do this on my own, your code exemple / guidance would be needed for sure... ) I will have a look at http://matplotlib.org/devel/index.html I think your idea of having a separate TriFinder class is quite good. My search algo. is not optimised, only avoiding a O(N) for interpolations along a path or line. Some other parts of the code (especially the loop over the (x,y) points in __call__() ) may also be performance-critical, at least for the 'cubic' interpolator. But I dont have a clear picture on how to embed C++ code in python so I would need your example to figure out what is possible. Regards Geoffroy. 2012年11月14日 Ian Thomas <ian...@gm...> > Hi Geoffroy, > > I have had some time to look at your TriLinearInterpolator in some detail > (the other two files only briefly). I would indeed like to add something > like this to matplotlib - the mesh refinement looks very nice and the > interpolators would be useful to many people. > > As you suspected, the code does need significant changes before we can > include it. Some are merely cosmetic, as all code must adhere to PEP8 and > the matplotlib coding guidelines, but there are also some functional and > performance improvements. For example, your wavefront method for finding > the triangle containing a certain point must be able to deal with masked > triangulations and indeed triangulations that are discontinuous, for > example two islands in a masked-out ocean, which is unusual but must be > supported. In terms of performance, there is much explicit looping within > numpy arrays that could be improved using other numpy array commands, and > would also reduce the length of the source code. There is an argument for > some of the performance-critical code to be in C/C++. > > I think the code used to determine which triangle contains a certain point > should be factored out into its own TriFinder class, so that (1) it does > not need to be replicated in the two interpolator classes, and (2) > different algorithms can be easily swapped if necessary. I have a C++ > TriFinder class that I could modify to work within matplotlib, and it is > O(log N) so should be faster than your version for typical use cases. > > I expect that this is probably more work than you anticipated when you > asked if the code needed any improvement! I propose the following: if you > are happy to give matplotlib your source code as it stands and for us to > include it under our BSD-style license, then I will take on the > responsibility of getting it into a form that will be accepted by the other > developers. I will acknowledge your contribution in both the source code > and on the web site, something like "based on code contributed by Geoffroy > Billotey". > > Alternatively, if you would like to use this as an excuse to learn how to > contribute to matplotlib more actively but don't want to take on > everything, then we could divide up the work so that first I write my C++ > log(N) TriFinder class and the linear interpolator that uses it, and then > you could modify the cubic interpolator following the format of the linear > interpolator and using my guidance as and when you need it. > > Let me know your preference, > Ian > > P.S. Never apologise for not being a computer scientist! Many of our > developers, myself included, are proper scientists or engineers!!! > > > > On 29 October 2012 09:37, Ian Thomas <ian...@gm...> wrote: > >> Hi Geoffroy >> >> This will certainly be very useful. I need to spend some time looking at >> it and seeing how it would best fit within the matplotlib framework, >> particularly as only a few days ago I committed to writing a triangular >> grid interpolator for quad grids and it would be sensible to group these >> interpolators together in some way. >> >> I'll get back to you when I've had time to look at it. >> >> Thanks for your efforts! >> Ian >> >> >> >> On 28 October 2012 20:17, GBillotey <geo...@gm...> wrote: >> >>> Hi! >>> >>> >>> I had recently to develop interpolators for a function defined at the >>> nodes >>> of a user-specified triangular mesh. >>> (Beside interpolation, it can help producing higher-quality tricontour >>> plots, using interpolation on a refined mesh and matplotlib tricontour >>> function.) >>> >>> Being a regular user of matplotlib, I would be happy if it can be useful >>> to >>> others... >>> The code is hosted here: >>> https://github.com/GBillotey/trimesh-interpolator.git >>> >>> >>> Please let me know if it this dev. can be useful and if the code needs >>> some >>> cleaning (I am not a computer scientist, only a mechanical engineer) >>> >>> >>> Cheers, >>> Geoffroy. >>> >> >