Matrix properties
number of rows	20,209
number of columns	20,209
nonzeros	139,233
structural full rank?	yes
structural rank	20,209
# 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 20209-by-20209
B	sparse 20209-by-7
C	sparse 6-by-20209

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'))	331,190	339,610
Cholesky flop count	1.4e+07	1.4e+07
nnz(L+U), no partial pivoting	642,171	659,011
nnz(V) for QR, upper bound nnz(L) for LU	790,024	794,309
nnz(R) for QR, upper bound nnz(U) for LU	1,698,034	1,683,407

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.