Changes between Version 2 and Version 4 of Ticket #28543


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Timestamp:
09/27/19 20:20:23 (13 months ago)
Author:
egourgoulhon
Comment:

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  • Ticket #28543

    • Property Status changed from new to needs_review
    • Property Cc tscrim added
  • Ticket #28543 – Description

    v2 v4  
    33Gamma^k^,,ij,, = (De,,i,,)(f,,k,, , e,,j,,)
    44
    5 where (f,,k,,) stands for the coframe dual to (e,,i,,). In the current implementation, this is performed by a triple loop on k, i and j with a recomputation of De,,i,, at each stage of the inner loop (!). This makes the whole computation terribly slow for manifold dimensions > 2. This ticket reorders the loops, factoring De,,i,,. As a result, in Sage 8.9.rc1, we pass from
     5where (f,,k,,) stands for the coframe dual to (e,,i,,). In the current implementation, this is performed by a triple loop on k, i and j with a recomputation of De,,i,, at each stage of the inner loop (!). This makes the whole computation terribly slow for manifold dimensions > 2. This ticket reorders the loops, factoring De,,i,,. As a result, in Sage 8.9.rc1, we move from
    66{{{
    77sage -t --long src/sage/manifolds/differentiable/affine_connection.py