[SciPy-dev] Inclusion of cython code in scipy
Thu Apr 24 19:35:30 CDT 2008
On Fri, Apr 25, 2008 at 1:47 AM, Neal Becker <firstname.lastname@example.org> wrote:
> Prabhu Ramachandran wrote:
> > Brian Granger wrote:
> >>> > C++ STL containers are truly great for things like this. I would
> >>> > write a simple c++ header file that defines the Particle class,
> >>> > create an std::vector<Particle> to hold them and wrap the whole thing
> >>> > into
> >>> > Cython. I have already done stuff like this (templated c++ with STL)
> >>> > with cython and it works great. Furthermore, you end up with an
> >>> > actual C/Python extension type that 1) is super fast 2) has its own C
> >>> > api that can be called from other C extensions.
> > For some strange reason I still haven't gotten this email but Brian,
> > that is the point I was making, STL has all the needed container classes
> > for this and this is precisely what I use. I just use SWIG to wrap this
> > C++ code and it works great. Much of the STL is already wrapped via
> > SWIG and with numpy.i it interfaces quite well with numpy, in addition
> > you can inject doxygen generated documentation almost automatically so
> > your generated wrapper code is fully documented.
> > I've also explored using D and PyD and it makes for a fantastic
> > combination. D seems to be (gdc) about 1.7 times slower than C++ but is
> > really nice to work with. PyD's support for numpy is lacking but could
> > be fixed.
> > The point is (and what I understand of what Nathan was saying), pyrex
> > and cython let you wrap the code to an extent but do not provide the
> > underlying solution. People were arging that Cython may be used in
> > place of C, and I think our point is that it isn't there yet and for
> > people used to C or C++ it is much easier to just use those instead.
> >> Unfortunately, the context I have done this in is proprietary code for
> >> my employer. But, I will try to put together a simple example this
> >> weekend and post it to launchpad. The documentation on these
> >> capabilities of Cython isn't great right now for sure, so some example
> >> code would sure help.
> > So why don't we do this together. I'll put together my tiny example of
> > a shootout with Python C++ and D and lets see how they stack up. If you
> > would be so kind you can add the cython/pyrex parts to this. Thanks.
> Is pyd still actively developed? Seems to be rather quiet for a while.
I don't think Kirk is doing a lot of development on it, but he's still
around in the D community. Nice to see some other folks here keeping
an eye on D.
BUT ... I think this thread was about alternatives for rewriting
parts of NumPy, and I have to say that writing *any* of numpy in D
seems like the wrong choice at this point.
Examples of using D with numpy on the numpy wiki would be great though.
Also, Prabhu, I can back up your "1.7x slower than C++" assessment.
My own tests have usually come out around that ballpark too. But I
prefer to phrase it as "560 times faster than pure Python". :-)
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