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Re: new snapshot?
From: |
Søren Hauberg |
Subject: |
Re: new snapshot? |
Date: |
Thu, 25 Feb 2010 13:40:41 -0800 |
tor, 25 02 2010 kl. 16:25 -0500, skrev John W. Eaton:
> That fixed all the eigs failures for me, but I'm still seeing the
> following failure in svds, which uses eigs:
>
> >>>>> processing /export/home/jwe/src/octave/scripts/sparse/svds.m
> ***** testif HAVE_ARPACK
> [u2,s2,v2,flag] = svds(a,k,0);
> s2 = diag(s2);
> assert(flag,!1);
> assert(s(k:-1:1), s2, 1e-10);
> !!!!! test failed
> assert (s (k:-1:1),s2,1e-10) expected
> 38.060
> 38.060
> 38.034
> 38.034
> 38.015
> 38.015
> 38.004
> but got
> 38.060
> 38.034
> 38.034
> 38.015
> 38.015
> 38.004
> 38.004
> maximum absolute error 0.0263523 exceeds tolerance 1e-10
>
> The test is:
>
> n = 100;
> k = 7;
> a =
> sparse([3:n,1:n,1:(n-2)],[1:(n-2),1:n,3:n],[ones(1,n-2),0.4*n*ones(1,n),ones(1,n-2)]);
> [u,s,v] = svd(full(a));
> s = diag(s);
> [dum, idx] = sort(abs(s));
> s = s(idx);
> u = u(:,idx);
> v = v(:,idx);
> randn('state',42)
>
> [u2,s2,v2,flag] = svds(a,k,0);
> s2 = diag(s2);
> assert(flag,!1);
> assert(s(k:-1:1), s2, 1e-10);
>
> If I run this test in a copy of Octave compiled *without* --enable-64,
> I sometimes see also the error now. The problem does not happen every
> time I run the test. So it seems like some kind of memory error, but
> valgrind is not telling me anything.
>
> I'm compiling with CXXFLAGS=-ggdb3 CFLAGS=-ggdb3, GCC version 4.4.3
> 20100108 (prerelease) (Debian 4.4.2-9) on an amd64 system.
>
> Can anyone else duplicate this problem?
I am seeing this problem on a checkout from before your changes (haven't
tried with your changes):
$ hg tip
changeset: 10339:de2d43bcb083
tag: tip
user: Jaroslav Hajek <address@hidden>
date: Fri Feb 19 11:47:47 2010 +0100
summary: optimize some lazy index operations
This is on an AMD64 system running a 32-bit Ubuntu install. Perhaps this
is related to running a 32-bit OS on a 64-bit machine?
I got CXXFLAGS='-g -O2' using gcc 4.4.1.
Soren
- Re: new snapshot?, (continued)
- Re: new snapshot?, Ben Abbott, 2010/02/18
- new snapshot?, John W. Eaton, 2010/02/18
- Re: new snapshot?, Jaroslav Hajek, 2010/02/18
- Re: new snapshot?, John W. Eaton, 2010/02/18
- Re: new snapshot?, David Bateman, 2010/02/18
- Re: new snapshot?, John W. Eaton, 2010/02/24
- Re: new snapshot?, Jaroslav Hajek, 2010/02/25
- Re: new snapshot?, John W. Eaton, 2010/02/25
- Re: new snapshot?, John W. Eaton, 2010/02/25
- Re: new snapshot?,
Søren Hauberg <=
- Re: new snapshot?, Michael D. Godfrey, 2010/02/26
- Re: new snapshot?, John W. Eaton, 2010/02/26
- Re: new snapshot?, Michael D. Godfrey, 2010/02/26
- Re: new snapshot?, Jaroslav Hajek, 2010/02/26
- Re: new snapshot?, Michael D. Godfrey, 2010/02/26
- Re: new snapshot?, John W. Eaton, 2010/02/26
- Re: new snapshot?, Michael D. Godfrey, 2010/02/26
- Re: new snapshot?, Michael D. Godfrey, 2010/02/26
- Re: new snapshot?, Michael D. Godfrey, 2010/02/26
- Re: new snapshot?, David Bateman, 2010/02/28