20 Sep 2007 15:01
Re: Anyone have a well-tested SWIG-based C++ STL valarray <=> numpy.array typemap to share?
David Cournapeau <david <at> ar.media.kyoto-u.ac.jp>
2007-09-20 13:01:13 GMT
2007-09-20 13:01:13 GMT
Alexander Schmolck wrote: > "Charles R Harris" <charlesr.harris <at> gmail.com> writes: > > >> The automatic handling of pointers for the default allocation type is also >> convenient and makes it reasonable to have functions return matrices and >> vectors. >> > > Hmm, I wonder whether I missed something when I read the manual. I didn't see > anything in the docs that suggests that ublas matrices do COW, reference > semantics or anything else to make C++'s horrible pass-by-value semantics > bearable performancewise, so I return and pass in shared_ptr's to matrices, > which is syntactically ugly but avoids the need to write a (reference > semantics) wrapper class for matrix. Am I missing some easier way to > efficiently return and pass large matrices? > If ublas is using expression template, shouldn't it alleviate somewhat this problem ? cheers, David
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