Matrix: MathWorks/Kaufhold
Description: John Kaufhold, GE. Triggers bug in LU in MATLAB 6.5 on Windows (not Linux)
(undirected graph drawing) |
Matrix properties | |
number of rows | 8,765 |
number of columns | 8,765 |
nonzeros | 42,471 |
structural full rank? | yes |
structural rank | 8,765 |
# of blocks from dmperm | 256 |
# strongly connected comp. | 256 |
explicit zero entries | 0 |
nonzero pattern symmetry | symmetric |
numeric value symmetry | 78% |
type | real |
structure | unsymmetric |
Cholesky candidate? | no |
positive definite? | no |
author | Kaufhold |
editor | T. Davis |
date | 2006 |
kind | counter-example problem |
2D/3D problem? | no |
Ordering statistics: | result |
nnz(chol(P*(A+A'+s*I)*P')) with AMD | 46,565 |
Cholesky flop count | 4.4e+05 |
nnz(L+U), no partial pivoting, with AMD | 84,365 |
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD | 99,409 |
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD | 204,810 |
SVD-based statistics: | |
norm(A) | 1e+15 |
min(svd(A)) | 2.0662 |
cond(A) | 4.83981e+14 |
rank(A) | 8,759 |
sprank(A)-rank(A) | 6 |
null space dimension | 6 |
full numerical rank? | no |
singular value gap | 2.29824 |
singular values (MAT file): | click here |
SVD method used: | s = svd (full (A)) ; |
status: | ok |
For a description of the statistics displayed above, click here.
Maintained by Tim Davis, last updated 12-Mar-2014.
Matrix pictures by cspy, a MATLAB function in the CSparse package.
Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.