Matrix: HB/lund_a
Description: SYMMETRIC MATRIX A OF LUND EIGENVALUE PROBLEM, MAY 1974
(undirected graph drawing) |
Matrix properties | |
number of rows | 147 |
number of columns | 147 |
nonzeros | 2,449 |
structural full rank? | yes |
structural rank | 147 |
# of blocks from dmperm | 1 |
# strongly connected comp. | 1 |
explicit zero entries | 0 |
nonzero pattern symmetry | symmetric |
numeric value symmetry | symmetric |
type | real |
structure | symmetric |
Cholesky candidate? | yes |
positive definite? | yes |
author | T. Johansson |
editor | A. Curtis, I. Duff, J. Reid |
date | 1974 |
kind | structural problem |
2D/3D problem? | yes |
Ordering statistics: | result |
nnz(chol(P*(A+A'+s*I)*P')) with AMD | 2,339 |
Cholesky flop count | 4.2e+04 |
nnz(L+U), no partial pivoting, with AMD | 4,531 |
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD | 2,768 |
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD | 4,629 |
SVD-based statistics: | |
norm(A) | 2.23854e+08 |
min(svd(A)) | 80.0351 |
cond(A) | 2.79695e+06 |
rank(A) | 147 |
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.