Matrix: GHS_psdef/obstclae
Description: Gould, Hu, & Scott: quadratic obstacle problem (CUTEr)
(undirected graph drawing) |
Matrix properties | |
number of rows | 40,000 |
number of columns | 40,000 |
nonzeros | 197,608 |
structural full rank? | yes |
structural rank | 40,000 |
# of blocks from dmperm | 5 |
# strongly connected comp. | 5 |
explicit zero entries | 0 |
nonzero pattern symmetry | symmetric |
numeric value symmetry | symmetric |
type | real |
structure | symmetric |
Cholesky candidate? | yes |
positive definite? | yes |
author | R. Dembo, U. Tulowitzki |
editor | P. Toint |
date | 1983 |
kind | optimization problem |
2D/3D problem? | no |
Ordering statistics: | result |
nnz(chol(P*(A+A'+s*I)*P')) with AMD | 1,058,836 |
Cholesky flop count | 1.2e+08 |
nnz(L+U), no partial pivoting, with AMD | 2,077,672 |
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD | 2,073,834 |
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD | 3,783,582 |
SVD-based statistics: | |
norm(A) | 8.1995 |
min(svd(A)) | 0.2 |
cond(A) | 40.9975 |
rank(A) | 40,000 |
sprank(A)-rank(A) | 0 |
null space dimension | 0 |
full numerical rank? | yes |
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.