I have questions about RDF (and CDF) sparse matrices. How are they implemented?
-for dense matrices, sage uses Scipy matrices and this is transparent. -but, how are sparse matrices (RDF,CDF) implemented? 1) Are they Scipy matrices ?2) if yes: there are different data structures for sparse matrices in scipy:
a) an intermediate version which uses a list representation,
not good for number crunching,
b) csc and csr format, which are extremely common in numerical
linear algebra (SuperLU uses them, and iterative methods too).
How hare matrix(RDF,...sparse=True) stored?If it is possible for sage to build automatically csc or csr matrices, then using sparse solvers is trivial. Otherwise I think it is necessary to build Scipy matrices (lil matrices converted to csr or csc format).
Thank you in advance. t.d. -- To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
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