Matrix: HB/bcsstk23
Description: SYMMETRIC STIFFNESS MATRIX - PORTION OF A 3D GLOBALLY TRIANGLULAR BLDG
(undirected graph drawing) |
Matrix properties | |
number of rows | 3,134 |
number of columns | 3,134 |
nonzeros | 45,178 |
structural full rank? | yes |
structural rank | 3,134 |
# 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 | J. Lewis |
editor | I. Duff, R. Grimes, J. Lewis |
date | 1984 |
kind | structural problem |
2D/3D problem? | yes |
Ordering statistics: | result |
nnz(chol(P*(A+A'+s*I)*P')) with AMD | 431,344 |
Cholesky flop count | 1.3e+08 |
nnz(L+U), no partial pivoting, with AMD | 859,554 |
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD | 741,699 |
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD | 1,261,838 |
SVD-based statistics: | |
norm(A) | 2.25804e+16 |
min(svd(A)) | 8535.28 |
cond(A) | 2.64554e+12 |
rank(A) | 3,133 |
sprank(A)-rank(A) | 1 |
null space dimension | 1 |
full numerical rank? | no |
singular value gap | 1.67394 |
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.