One can obtain the PLU factorisation of a matrix in sage as in the following example:
M=matrix([[1,1],[1,2]])
display(M.LU())
Is there a way to see which exact algortihm is used (and what the exact code is) for Sage to calculate the PLU factorisation of a given matrix? I tried LU??, but it does not work for this command. I also searched for LU in https://doc.sagemath.org/ but was not able to find anything.
Sage relies on Python, hich is object oriented. This means that there is no global LU function, but possibly several LU methods that can only be applied to some particular objects. So, to get the source code of the LU method that will be applied to your matrix, you need to specify the matrix:
sage: M.LU??
Thank you! I find the reference "[TB1997]" but where can I look it up what exact book or article this is? And it seems for integer matrices always the same algorithm is used.
Ah, I think I found it here: http://sporadic.stanford.edu/referenc... : "Lloyd N. Trefethen and David Bau III, Numerical Linear Algebra, SIAM, Philadelphia, 1997." Thanks again!
Asked: 2024-12-28 10:50:49 +0100
Seen: 24 times
Last updated: Dec 28 '24
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