Matrix properties
number of rows	1,434
number of columns	1,434
nonzeros	18,228
structural full rank?	yes
structural rank	1,434
# of blocks from dmperm	30
# strongly connected comp.	30
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. Li, M. Kamon
editor	E. Rudnyi
date	2006
kind	model reduction problem
2D/3D problem?	yes

Additional fields	size and type
E	sparse 1434-by-1434
B	sparse 1434-by-1

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'))	9,856	14,996	9,856
Cholesky flop count	1.7e+05	4.5e+05	1.7e+05
nnz(L+U), no partial pivoting	18,278	28,558	18,278
nnz(V) for QR, upper bound nnz(L) for LU	18,782	20,897	15,887
nnz(R) for QR, upper bound nnz(U) for LU	35,555	49,612	35,555

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.