Andy, > We currently have several students interested in symbolic sparse > matrix calculations for GSOC. IMHO, we could use a linear algebra > interface more compatible with scipy.linalg but I don't have a use for > symbolic sparse matrices. > > Since I believe in not adding unnecessary features to a library, I > would like to know who the customers of a symbolic sparse matrix > format would be and what applications, point to code please, we need > to speed up.
In sympy.physics.quantum.qubit and gate we have extremely large and very sparse symbolic unitary matrices. The sizes are as big as any machine anyone has around. Currently we have support for sympy.Matrix, numpy matrices and scipy.sparse, but we don't have any way of handling large symbolic matrices. For *us* it would be killer to have this capability in sympy, as in many cases, it is important to have things in symbolic form. But, with that said, I can't think of many (or any) other cases where sparse symbolic matrices are useful. Another way of handling symbolic sparse matrices would be to add suppor to scipy.sparse (numpy already has this support) for having arbitrary objects as elements. I should also mention that we are pretty much only interested in matrix-vector multiplies, matrix-scalar mult. and matrix addition. We can write some code examples if that would help. Cheers, Brian > Also how big are the matrices you are working with. You have to > remember that sparse matrices usually don't make sense on typical > numerical algorithms until you hit about 1000x1000, because optimized > BLAS can stream so much better. I would guess the number is much > lower with symbolics, but the storage will not be an issue until that > size since we only have a pointer to S(0). > > Having this information would be quite beneficial in organizing what > the student projects should implement. > > -- Andy > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To post to this group, send email to sympy@googlegroups.com. > To unsubscribe from this group, send email to > sympy+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/sympy?hl=en. > > -- Brian E. Granger Cal Poly State University, San Luis Obispo bgran...@calpoly.edu and elliso...@gmail.com -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to sympy@googlegroups.com. To unsubscribe from this group, send email to sympy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
