Changes between Initial Version and Version 1 of Ticket #22090, comment 8


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Timestamp:
01/06/17 14:30:06 (2 years ago)
Author:
rws
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  • Ticket #22090, comment 8

    initial v1  
    1 Still missing is better documentation. As to performance 75% of complicated summations are spent in computation of one symbolic matrix determinant, of which 2/3 is expansions. It is astonishing that the 12x12 matrix determinant from the summation of `(((n^4-14*n^2-24*n-9) * 2^n / n^2 / (n+1)^2 / (n+2)^2 / (n+3)^2))` needs 4,316 first level expansions, even with the supposedly optimized "enhanced Laplace-expansion" determinant algorithm used.
     1Still missing is better documentation. As to performance 75% of complicated summations are spent in computation of one symbolic matrix determinant, of which 2/3 is expansions. It is astonishing that the 12x12 matrix determinant from the summation of `(((n^4-14*n^2-24*n-9) * 2^n / n^2 / (n+1)^2 / (n+2)^2 / (n+3)^2))` needs 4,316 first level expansions, even with the supposedly optimized "enhanced Laplace-expansion" determinant algorithm used. Resultants should be later computed in Pynac via Singular which apparently uses a subresultant algorithm.