updated on October 11 2012

maintained by Julien Langou, U. Colorado Denver and Julie Langou, U. Tennessee

RED means BUG WAS CONFIRMED but IT IS STILL HERE

ORANGE means BUG WAS NOT CONFIRMED

GREEN means BUG WAS CORRECTED :

bug0101 :: [S,D, C, Z]hsein: NaN in H can cause an infinite loop

  • CORRECTED, rev 1350

  • Present in LAPACK 3.4.2

  • bug report by Alexander Kobotov (INTEL) on October 3 2012

  • See forum topic 3928

  • added check for NaN after the norm of each block of H is computed

  • if NaN is detected, returns with INFO=-6 (H is the 6th parameter)

  • Corrected by Rodney on Thu Oct 11

bug0061 :: zgehrd.f is overflowing

  • CONFIRMED

  • bug report by Victor Liu on Tuesday August 03rd, 2010

  • zgehrd.f is overflowing the maximum size in bytes of the largest array that

  • can be put on the stack with gfortran (⇒ leads ,e.g., to non-reproducible and uncorrect execution

  • of zgeev in multithreaded context

  • lapackers involved in the bug fix process: Julie and Julien Langou and Mathieu Faverge

  • bug fix by Victor Liu on Wednesday August 04th, 2010

  • see forum topic 1930

  • two outstanding issues: (1) how do we go to fix this?, (2) more LAPACK subroutines might be concerned.

bug0057 :: Non-eigenvectors from DGEEV, problem in balancing

  • CONFIRMED

  • bug report sent by Numpy team on April 22nd, 2010

  • see forum topic 1818

  • see follow-up on lapackers on April 22nd from Jim "bug in DGEHRD" "The balancing is choosing to scale some rows/columns by factors like 1e18, which rather amplifies tiny rounding errors in the (presumably correctly) computed eigenvectors of the balanced matrix, when balancing is undone at the end. The expert driver interface dgeevx would let the user disable balancing, until we figure out whether this is a bug or a feature, I’m not sure which."

bug0056 :: Non-orthogonal eigenvectors returned from DSYEVR

  • CONFIRMED

  • bug report sent by Scipy team on April 22nd

  • see LAPACK Mailing list msg 874

  • Confirmed by Rodney on Tue, 17 Feb 2011

  • " I can reproduce similar problems that the user encountered with non-orthogonal eigenvectors when only

  • a few eigenvalues are requested. This also happens with SSYEVR. If I set ABSTOL to SLAMCH(Safe minimum),

  • the problem goes away in SSYEVR, and improves with DSYEVR but does not completely go away."

bug0033 :: failure of zheevd on a specific matrix

bug0032 :: matrix splitting problem with dstebz and sstebz

  • CONFIRMED

  • bug report sent by Phil DeMier (IBM) on Mon 29 Jun 2009 to "lapack@cs.utk.edu". "matrix splitting problem with dstebz and sstebz"

  • see Phil DeMier’s email and Phil DeMier’s test code

  • Confirmed by Rodney on Tue, 17 Feb 2011