Matrix: DRIVCAV/cavity18
Description: Driven Cavity 20 x 20, Reynolds number: 200
(bipartite graph drawing) | (graph drawing of A+A') |
Matrix properties | |
number of rows | 4,562 |
number of columns | 4,562 |
nonzeros | 138,040 |
structural full rank? | yes |
structural rank | 4,562 |
# of blocks from dmperm | 322 |
# strongly connected comp. | 322 |
explicit zero entries | 147 |
nonzero pattern symmetry | 95% |
numeric value symmetry | 0% |
type | real |
structure | unsymmetric |
Cholesky candidate? | no |
positive definite? | no |
author | A. Chapman |
editor | A. Baggag, Y. Saad |
date | 1996 |
kind | subsequent computational fluid dynamics problem |
2D/3D problem? | yes |
Additional fields | size and type |
b | full 4562-by-1 |
x | full 4562-by-1 |
Notes:
next: DRIVCAV/cavity19 first: DRIVCAV/cavity16 pattern is the same as DRIVCAV/cavity16
Ordering statistics: | result |
nnz(chol(P*(A+A'+s*I)*P')) with AMD | 173,690 |
Cholesky flop count | 1.1e+07 |
nnz(L+U), no partial pivoting, with AMD | 342,818 |
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD | 341,666 |
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD | 1,150,538 |
Note that all matrix statistics (except nonzero pattern symmetry) exclude the 147 explicit zero entries.
SVD-based statistics: | |
norm(A) | 13.1764 |
min(svd(A)) | 1.40805e-06 |
cond(A) | 9.35789e+06 |
rank(A) | 4,562 |
sprank(A)-rank(A) | 0 |
null space dimension | 0 |
full numerical rank? | yes |
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.