On Monday 25 April 2011 20:49:34 Jonathan Hartley wrote: > On Apr 20, 2:43 pm, Andreas Tawn <andreas.t...@ubisoft.com> wrote: > > > Algis Kabaila <akaba...@pcug.org.au> writes: > > > > Are there any modules for vector algebra (three > > > > dimensional vectors, vector addition, subtraction, > > > > multiplication [scalar and vector]. Could you give me > > > > a reference to such module? > > > > > > NumPy has array (and matrix) types with support for these > > > basic operations you mention. See the tutorial > > > athttp://numpy.scipy.org/ > > > > You might also want to > > considerhttp://code.google.com/p/pyeuclid/ > > > > Cheers, > > > > Drea > > Stealing this from Casey Duncan's recent post to the Grease > users list: > > > - (ab)use complex numbers for 2D vectors (only). Very fast > arithmetic and built-in to Python. Downside is lack of > abstraction. > > - Use pyeuclid (pure python) if ultimate speed isn't an > issue, or if compiled extensions are. It supports 3D and has > a nice api > > - vectypes is a more recent project from the same author as > pyeuclid. It offers a more consistent 'GLSL' like interface, > including swizzling, and internally seems to have more > maintainable code because it generates various sizes of > vector and matrix from a single template. This is done > without performance penalty because the generation is done > at design time, not runtime. > > - Use pyeigen if you want fast vectors, and don't mind > compiling some C/C++. I don't know how the Python api looks > though > > - Use numpy if you want fast batch operations Jonathan,
Thank you for a nice and extensive list of references. To clarify my position - surprisingly, speed is not an issue- I've programmed a matrix in pure python (3, but mainly iwth python 2 syntax) and found that inversion was quite fast enough for my requirements. Good vector algebra is necessary for 3 D frame analysis, so a vector package is indicated. numpy is great, but it is a tool like a sledge to drive a nail... OldAl. -- Algis http://akabaila.pcug.org.au/StructuralAnalysis.pdf -- http://mail.python.org/mailman/listinfo/python-list
