From bug-octave-request at bevo dot che dot wisc dot edu  Mon Nov  8 12:32:59 1999
Subject: Re: Test fails - octave-2.1.20 on irix6.5
From: "John W. Eaton" <jwe at bevo dot che dot wisc dot edu>
To: Joao Cardoso <jcardoso at inescn dot pt>
Cc: bug-octave at bevo dot che dot wisc dot edu, David.Billinghurst@riotinto.com.au
Date: Mon, 8 Nov 1999 12:32:06 -0600 (CST)



On  8-Nov-1999, Joao Cardoso <jcardoso at inescn dot pt> wrote:

| "Billinghurst, David (RTD)" wrote:
| 
| > Just built octave-2.1.20 on irix6.5 with both gcc-2.95.1 and egcs 19991102
| > snapshot.
| >
| > I get a failure on test poly/residue-1.m as it misses the allowed tolerances
| >
| > by an order of magnitude. Haven't done a full error analysis, but I suspect
| > the tolerances may be a little tight.
| >
| > The test case poly/residue-1.m is
| >
| > b = [1, 1, 1];
| > a = [1, -5, 8, -4];
| > [r, p, k, e] = residue (b, a);
| > (abs (r - [-2; 7; 3]) < sqrt (eps)
| >  && abs (p - [2; 2; 1]) < sqrt (eps)
| >  && isempty (k)
| >  && e == [1; 2; 1])
| >
| > For octave-2.1.20 this fails as
| >
| > r - [-2; 7; 3]  =
| >    -1.0658e-14
| >     1.7276e-07
| >     1.1990e-14
| >
| > while sqrt (eps) =  1.4901e-08
| 
| I also have this problem with SCO. However the same test in
| octave-2.1.14 runs OK.

The roots function uses eig, and Lapack was updated to 3.0 for
2.1.20.  Could that be the cause of the problem?  It seems to work
fine on my Linux system.

jwe



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