Hi, On 28 May 2011 15:56, SherjilOzair <sherjiloz...@gmail.com> wrote:
> I would like to know how and where Sympy's matrices are used. > Is Sympy matrices used for numeric computing anywhere ? > btw. mpmath has support for matrices with inexact coefficients. > Are Sympy Matrices expected to offer any advantage that matrices in > numpy/scipy or other libraries cannot offer ? > > Is its use limited to symbolic ? What size of Matrices with symbolic > content is used ? > Operations on Expr are way costlier than operations on numerics. So, > knowing the size of the symbolic matrices that are required would help > me in optimization when writing algorithms for sparse matrices, and > also when refactoring Matrix. > > I expect that one cannot use too large symbolic matrices, as solving/ > inversing/etc. would result in expression blowup. > > I would be glad if you could also tell what running time you would > expect from the matrices that you use. > Look into heurish(), ratint(), gosper_sum(), apart(), rsolve_*() (maybe other). They all use solver of linear systems. A few print statements will give you a clue how big and dense are those matrices and what are the typical types of coefficients. Running sympy.integrals tests this way reveals that the largest matrix was 100 x 71 and there were very many matrices of size around 20 x 20 and larger. It's up to you to perform detailed analysis, but the larger symbolic matrices we will be able to support the better. As to coefficients I would assume that it will be rationals in most cases, but from private discussions and a few issues (e.g. 1880) I know that support for large matrices with polynomial or rational function coefficients will be appreciated. > > -- > 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. > > Mateusz -- 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.
