Ravi wrote: > On Wednesday 21 January 2009 13:55:49 Neal Becker wrote: >> I'm only interested in simple strided 1-d vectors. In that case, I think >> your code already works. If you have c++ code using the iterator >> interface, the iterators dereference will use (*array )[index]. This >> will use operator[], which will call PyArray_GETPTR. So I think this >> will obey strides. > > You are right. I had forgotten that I had simple strided vectors working. > >> Unfortunately, it will also be slow. I suggest something like the >> enclosed. I have done some simple tests, and it seems to work. > > I wonder why PyArray_GETPTR1 is slow. Is it because of the implied integer > multiplication? Unfortunately, your approach means that iterators can > become invalid if the underlying array is resized to a larger size. Hmmh, > perhaps we could make this configurable at compile-time ... > > Thanks for the code. Could you provide some benchmarks on the relative > speeds of the two approaches? > > Regards, > Ravi Do you know about pyublas? This is the same issue we ran into there. I did not benchmark the code you sent me. I was just going by my experience with pyublas. I guess a benchmark would be a good idea.
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