[Matlisp-users] Re: Problem with function geev

[Paul L. I. <aea...@gm...>]

I would like to know if the patch at the bottom of this email solves
the geev problem for the other people who have reported it.  It solves
mine.

I have been having the same issue with geev.  Calling it causes cmucl
to go into an infinite loop.  In slime I can interrupt the program,
and then call geev again.  The second time no infinite loop occurs,
but the results are corrupted (i.e. The resulting matrices are
populated with silent-NaNs).

I have tracked the source of these problems down to a heisenbug in the
subroutines which determine parameters of the machine.  Unfortunately,
this patch could not possibly affect the real cause of the problem,
but if it works for other people besides me, it may help lead to the
real problem.

The logical effect of this patch is to cause the LAPACK routines to
assume the base of the machine is at least binary.

Index: dlamch.f
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
RCS file: /cvsroot/matlisp/matlisp/LAPACK/SRC/dlamch.f,v
retrieving revision 1.1
diff -u -w -r1.1 dlamch.f
--- dlamch.f=0915 Apr 2000 00:24:53 -0000=091.1
+++ dlamch.f=099 Aug 2005 02:47:52 -0000
@@ -231,7 +231,7 @@
 *
 *           fl( a + b ) .gt. a.
 *
-         B =3D 1
+         B =3D 2
          C =3D DLAMC3( A, B )
 *
 *+       WHILE( C.EQ.A )LOOP