MathWorks/TS
x=A\b triggers a bug in MATLAB R2009a and earlier
| Name |
TS |
| Group |
MathWorks |
| Matrix ID |
2256 |
|
Num Rows
|
2,142 |
|
Num Cols
|
2,142 |
|
Nonzeros
|
45,262 |
|
Pattern Entries
|
45,262 |
|
Kind
|
Counter Example Problem |
|
Symmetric
|
No |
|
Date
|
2009 |
|
Author
|
P. Quillen |
|
Editor
|
T. Davis |
| Structural Rank |
2,140 |
| Structural Rank Full |
false |
|
Num Dmperm Blocks
|
92 |
|
Strongly Connect Components
|
183 |
|
Num Explicit Zeros
|
0 |
|
Pattern Symmetry
|
95.3% |
|
Numeric Symmetry
|
4.1% |
|
Cholesky Candidate
|
no |
|
Positive Definite
|
no |
|
Type
|
real |
| SVD Statistics |
| Matrix Norm |
4.434200e+02 |
| Minimum Singular Value |
1.961143e-15 |
| Condition Number |
2.261028e+17
|
| Rank |
2,140 |
| sprank(A)-rank(A) |
0 |
| Null Space Dimension |
2 |
| Full Numerical Rank? |
no |
| Download Singular Values |
MATLAB
|
| Download |
MATLAB
Rutherford Boeing
Matrix Market
|
| Notes |
This is a structurally singular matrix that triggers a bug in the
2-by-2 pivoting strategy in UMFPACK versions 4.1 through 5.3.
The bug thus exists in MATLAB R2006b through R2009a. It was
fixed in UMFPACK 5.4 and MATLAB R2009b. Contributed by Pat Quillen,
The MathWorks, Inc. The sprank(A) and rank(A) are 2140.
|
