Matrix properties
number of rows	66,917
number of columns	66,917
nonzeros	1,703,365
structural full rank?	yes
structural rank	66,917
# 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	J. Hildenbrand
editor	E. Rudnyi
date	2004
kind	model reduction problem
2D/3D problem?	yes

Additional fields	size and type
E	sparse 66917-by-66917
B	sparse 66917-by-1
C	sparse 28-by-66917
cname	full 28-by-7

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'))	55,993,092	22,241,935
Cholesky flop count	1.2e+11	1.8e+10
nnz(L+U), no partial pivoting	111,919,267	44,416,953
nnz(V) for QR, upper bound nnz(L) for LU	86,330,206	37,070,715
nnz(R) for QR, upper bound nnz(U) for LU	154,029,283	70,842,109

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.