Matrix properties
number of rows	79,841
number of columns	79,841
nonzeros	553,921
structural full rank?	yes
structural rank	79,841
# of blocks from dmperm	1
# strongly connected comp.	1
entries not in dmperm blocks	0
explicit zero entries	0
nonzero pattern symmetry	symmetric
numeric value symmetry	symmetric
type	real
structure	symmetric
Cholesky candidate?	no
positive definite?	no

author	P. Benner, J. Saak
editor	E. Rudnyi
date	2002
kind	model reduction problem
2D/3D problem?	yes

Additional fields	size and type
E	sparse 79841-by-79841
B	sparse 79841-by-7
C	sparse 6-by-79841

Notes:

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

Ordering statistics:	AMD	METIS
nnz(chol(P*(A+A'+s*I)*P'))	1,733,147	1,650,417
Cholesky flop count	1.4e+08	1.1e+08
nnz(L+U), no partial pivoting	3,386,453	3,220,993
nnz(V) for QR, upper bound nnz(L) for LU	4,639,030	4,078,059
nnz(R) for QR, upper bound nnz(U) for LU	10,074,013	8,800,326

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.