andrewssobral / andrewssobral/redsvd

U and V have last column all zeros

Aberta
#5 2 comentários 0 reações 0 responsáveis Ver no GitHub
auto-migrated Priority-Medium Type-Defect
Linguagem predominante
C++
Estrelas
7
Forks
3
Métricas de merge de PRs
Nenhum PR com merge em 30d

Descrição

```
What steps will reproduce the problem?
1.
>cat densa.txt
1.5 0.0 2.5 2.5
0.0 2.5 2.5 0.0
1.5 0.0 2.5 1.0
0.0 2.5 2.5 0.0
0.0 2.5 2.5 0.0
2.
redsvd -i densa.txt -o densa -f dense -r 10
3.
>cat densa.U
-0.401793 +0.706597 -0.582481 +0.000000
-0.486488 -0.308495 -0.038651 +0.000000
-0.358540 +0.463912 +0.810083 +0.000000
-0.486488 -0.308495 -0.038651 +0.000000
-0.486488 -0.308495 -0.038651 +0.000000
>cat densa.V
-0.165886 +0.472878 +0.409235 +0.000000
-0.530701 -0.623149 -0.347478 +0.000000
-0.807177 +0.164981 +0.334580 +0.000000
-0.198253 +0.600711 -0.774494 +0.000000

What is the expected output? What do you see instead?
First, I expected U to be 5 by 5.
Tried same matrix in gnu octave, and the first 3 column match exactly, but the
last one have values not zero:
octave-3.2.4:1> A=[1.5 0 2.5 2.5;0 2.5 2.5 0; 1.5 0 2.5 1.0; 0 2.5 2.5 0;0 2.5
2.5 0]
A =

1.50000 0.00000 2.50000 2.50000
0.00000 2.50000 2.50000 0.00000
1.50000 0.00000 2.50000 1.00000
0.00000 2.50000 2.50000 0.00000
0.00000 2.50000 2.50000 0.00000

octave-3.2.4:2> [u,s,v]=svd(A);
octave-3.2.4:3> u
u =

-4.0179e-01 7.0660e-01 5.8248e-01 1.9052e-16 -3.8365e-20
-4.8649e-01 -3.0849e-01 3.8651e-02 8.1650e-01 -1.2869e-16
-3.5854e-01 4.6391e-01 -8.1008e-01 -3.1762e-17 3.8365e-20
-4.8649e-01 -3.0849e-01 3.8651e-02 -4.0825e-01 -7.0711e-01
-4.8649e-01 -3.0849e-01 3.8651e-02 -4.0825e-01 7.0711e-01

octave-3.2.4:4> v
v =

-1.6589e-01 4.7288e-01 -4.0924e-01 7.6249e-01
-5.3070e-01 -6.2315e-01 3.4748e-01 4.5750e-01
-8.0718e-01 1.6498e-01 -3.3458e-01 -4.5750e-01
-1.9825e-01 6.0071e-01 7.7449e-01 1.1102e-16

What version of the product are you using? On what operating system?
Ubuntu 12.04
redsvd 0.2.0

Please provide any additional information below.
I don't sure it is an issue, I didn't find any other information to let me know
if this behavior is expected.
```

Original issue reported on code.google.com by `hecha...@gmail.com` on 27 Sep 2012 at 4:27

Guia de contribuição

Nenhum guia de contribuição indexado para este repositório

Avaliação

Esta issue ainda não foi avaliada.

Receba novas issues na sua caixa de entrada

Um resumo curto de issues do GitHub para quem está começando.