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
entries not in dmperm blocks	5,740
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:	AMD	METIS	DMPERM+
nnz(chol(P*(A+A'+s*I)*P'))	1,040,340	1,111,784	1,010,559
Cholesky flop count	1.2e+08	1.4e+08	1.1e+08
nnz(L+U), no partial pivoting	2,068,950	2,211,838	2,015,128
nnz(V) for QR, upper bound nnz(L) for LU	1,059,692	1,172,256	844,166
nnz(R) for QR, upper bound nnz(U) for LU	1,393,718	2,347,145	1,561,784

Maintained by Tim Davis, last updated 30-Sep-2008.
Matrix pictures by cspy, a MATLAB function in the CSparse package.
Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.