|Re: [eigen] TriangularView::solve() interface|
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- To: eigen@xxxxxxxxxxxxxxxxxxx
- Subject: Re: [eigen] TriangularView::solve() interface
- From: Benoit Jacob <jacob.benoit.1@xxxxxxxxx>
- Date: Mon, 24 Aug 2009 10:47:39 -0400
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2009/8/24 Jitse Niesen <jitse@xxxxxxxxxxxxxxxxx>:
> While rewriting part of the tutorial, I noticed that the new
> TriangularView::solve() function returns the solution vector, while the
> other solve functions pass the solution via one of the parameters. Compare
> x = A.triangularView<UpperTriangular>().solve(b);
> A.partialLu().solve(b, &x);
> Was this done on purpose?
Hm, question for Gael, but indeed this is a bit strange. we need to
unify how we use a single given word thoughout eigen.
> The docs on the eigen website  were magically updated,
Thanks to Thomas who has set a cron job on his machine!
> but some of the
> latex was not parsed correctly. Am I doing anything wrong? Everything works
> fine on my own computer.
I didn't know about the "aligned" environment, perhaps it requires a
special package. The standard way to do that would be eqnarray*. Then
you put & on both sides of =. This will also look better.
> Something to perhaps add to the to-do list: a routine to estimate the
> condition number of a matrix based on the LU decomposition.
Is that possible at all? I assume that by condition number we mean the
ratio between the biggest and smallest eigenvalue. I don't think that
the LU decomposition sees that! The SVD, Schur, and diagonalizations
are the ones that can be used here.