Matrix: VanVelzen/std1_Jac2
Description: Chemical process simulation, Nils van Velzen (complete problem)
(bipartite graph drawing) | (graph drawing of A+A') |
Matrix properties | |
number of rows | 21,982 |
number of columns | 21,982 |
nonzeros | 1,248,213 |
structural full rank? | yes |
structural rank | 21,982 |
# of blocks from dmperm | 11,091 |
# strongly connected comp. | 1 |
explicit zero entries | 518 |
nonzero pattern symmetry | 0% |
numeric value symmetry | 0% |
type | real |
structure | unsymmetric |
Cholesky candidate? | no |
positive definite? | no |
author | N. van Velzen |
editor | T. Davis |
date | 2006 |
kind | chemical process simulation problem |
2D/3D problem? | no |
Additional fields | size and type |
b | full 21982-by-1 |
Ordering statistics: | result |
nnz(chol(P*(A+A'+s*I)*P')) with AMD | 43,523,834 |
Cholesky flop count | 2.5e+11 |
nnz(L+U), no partial pivoting, with AMD | 87,025,686 |
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD | 6,583,192 |
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD | 17,960,469 |
Note that all matrix statistics (except nonzero pattern symmetry) exclude the 518 explicit zero entries.
SVD-based statistics: | |
norm(A) | 4.46217e+11 |
min(svd(A)) | 2.36735e-15 |
cond(A) | 1.88488e+26 |
rank(A) | 12,050 |
sprank(A)-rank(A) | 9,932 |
null space dimension | 9,932 |
full numerical rank? | no |
singular value gap | 1.00273 |
singular values (MAT file): | click here |
SVD method used: | s = piro_band_svd (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.