Matrix: HB/lshp2614
Description: SYMMETRIC MATRIX FROM ALAN GEORGE'S L-SHAPE PROBLEMS, 1978.
(undirected graph drawing) |
Matrix properties | |
number of rows | 2,614 |
number of columns | 2,614 |
nonzeros | 17,980 |
structural full rank? | yes |
structural rank | 2,614 |
# of blocks from dmperm | 1 |
# strongly connected comp. | 1 |
explicit zero entries | 0 |
nonzero pattern symmetry | symmetric |
numeric value symmetry | symmetric |
type | binary |
structure | symmetric |
Cholesky candidate? | yes |
positive definite? | no |
author | A. George |
editor | I. Duff, R. Grimes, J. Lewis |
date | 1978 |
kind | thermal problem |
2D/3D problem? | yes |
Ordering statistics: | result |
nnz(chol(P*(A+A'+s*I)*P')) with AMD | 58,911 |
Cholesky flop count | 2.3e+06 |
nnz(L+U), no partial pivoting, with AMD | 115,208 |
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD | 85,989 |
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD | 160,176 |
SVD-based statistics: | |
norm(A) | 6.98798 |
min(svd(A)) | 0.00134453 |
cond(A) | 5197.35 |
rank(A) | 2,614 |
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.