[Rd] Listing of LAPACK error codes

[Prof Brian Ripley]

On Wed, 25 Mar 2009, Orlando Döhring wrote:

> Professor Ripley commented on LAPACK error codes:
> https://stat.ethz.ch/pipermail/r-help/2007-March/127702.html and says
> "Internal LAPACK errors are usually problems with arithmetic accuracy,
> and as such are compiler- and CPU-specific."
>
> Is there a listing for the error codes from Lapack routine 'dsyevr'?
> Especially I am interested about the meaning and handling of error codes 1
> and 2. In Lapack.c I only see the reference to the variable info in certain
> Fortran code:

I read the LAPACK sources: I know of no other documentation.  (You 
seem to have missed the sources, which are part of R.)

>    F77_CALL(dsyevr)(jobv, range, uplo, &n, rx, &n, &vl, &vu, &il, &iu,
> &abstol, &m, rvalues, rz, &n, isuppz, &tmp, &lwork, &itmp, &liwork, &info);
>    if (info != 0)
>        error(_("error code %d from Lapack routine '%s'"), info, "dsyevr");
>    lwork = (int) tmp;
>    liwork = itmp;
>
>    work = (double *) R_alloc(lwork, sizeof(double));
>    iwork = (int *) R_alloc(liwork, sizeof(int));
>    F77_CALL(dsyevr)(jobv, range, uplo, &n, rx, &n, &vl, &vu, &il, &iu,
> &abstol, &m, rvalues, rz, &n, isuppz, work, &lwork, iwork, &liwork, &info);
>    if (info != 0)
>        error(_("error code %d from Lapack routine '%s'"), info, "dsyevr");
>
> 	[[alternative HTML version deleted]]

Overdue to read the posting guide ....

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595