bugGNU Octave - Bugs: bug #52999, Syntax change in eigs


bug #52999: Syntax change in eigs

Submitted by:  Marco Caliari <caliari>
Submitted on:  Mon 29 Jan 2018 08:45:46 AM UTC  
Category:  Octave Function Severity:  3 - Normal
Priority:  5 - Normal Item Group:  Matlab Compatibility
Status:  None Assigned to:  None
Originator Name:  Open/Closed:  Open
Release:  dev Operating System:  GNU/Linux

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Mon 29 Jan 2018 08:45:46 AM UTC, original submission:  

From R2017b, the syntax (and the underlying method) in eigs has changed (although the old syntax is still supported)


Fixing the syntax should not be difficult and should require only a modification of eigs.m. The underlying method is now the Krylov-Schur algorithm proposed by G. W. Stewart, which shares with ARPACK the Arnoldi factorization and other ideas. I am aware only of this free toy implementation


Due to the importance of the ARPACK package (used by octave, scilab, scipy, R, ...), I think that the right way to do could be an extension of the ARPACK modes to include the new algorithm, or a fork to a KSPACK. In this way, all the nice features already in ARPACK (single/double precision, symmetric/unsymmetric/complex routines, reverse communication) would be kept. Implementing from scratch the Krylov-Schur method in octave would be a huuuge amount of work.

Marco Caliari <caliari>
Project Member


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