Koutsovasilis/F2
AUDI engine piston rod; Panos Koutsovasilis, Technische Univ. Dresden
| Name |
F2 |
| Group |
Koutsovasilis |
| Matrix ID |
1861 |
|
Num Rows
|
71,505 |
|
Num Cols
|
71,505 |
|
Nonzeros
|
5,294,285 |
|
Pattern Entries
|
5,294,285 |
|
Kind
|
Structural Problem |
|
Symmetric
|
Yes |
|
Date
|
2007 |
|
Author
|
P. Koutsovasilis |
|
Editor
|
T. Davis |
| Structural Rank |
71,505 |
| Structural Rank Full |
true |
|
Num Dmperm Blocks
|
1 |
|
Strongly Connect Components
|
1 |
|
Num Explicit Zeros
|
0 |
|
Pattern Symmetry
|
100% |
|
Numeric Symmetry
|
100% |
|
Cholesky Candidate
|
yes |
|
Positive Definite
|
no |
|
Type
|
real |
| Download |
MATLAB
Rutherford Boeing
Matrix Market
|
| Notes |
Stiffness matrix from an AUDI engine piston rod. This matrix is an ill-
condition symmetric indefinite matrix. In MATLAB 7.4, the matrix is
factorized three times in x=A\b. Inside backslash, CHOLMOD is tried first
since the matrix is symmetric and all diagonal entries are positive. CHOLMOD
fails since the matrix is indefinite. Next, UMFPACK is used with default
pivot tolerances which maintain sparsity at the (rare) expense of a slight
decrease in accuracy. This succeeds, but the result is flagged as
potentially inaccurate because the condition estimate is high. UMFPACK is
then used again with more conservative tolerances (but more fill-in).
|
