Matrix properties
number of rows	11,730
number of columns	11,730
nonzeros	328,323
structural full rank?	yes
structural rank	11,730
# of blocks from dmperm	331
# strongly connected comp.	331
explicit zero entries	0
nonzero pattern symmetry	61%
numeric value symmetry	0%
type	real
structure	unsymmetric
Cholesky candidate?	no
positive definite?	no

author	K. Willcox, G. Lassaux, D. Gratton
editor	E. Rudnyi
date	2006
kind	model reduction problem
2D/3D problem?	yes

Additional fields	size and type
E	sparse 11730-by-11730
B	sparse 11730-by-2
C	sparse 1-by-11730

Notes:

Primary matrix in this model reduction problem is the Oberwolfach A matrix

Ordering statistics:	result
nnz(chol(P*(A+A'+s*I)*P')) with AMD	1,040,340
Cholesky flop count	1.2e+08
nnz(L+U), no partial pivoting, with AMD	2,068,950
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	1,059,692
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	1,393,718

SVD-based statistics:
norm(A)	6.57342
min(svd(A))	1.69358e-06
cond(A)	3.88137e+06
rank(A)	11,730
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.