Matrix properties
number of rows	19,994
number of columns	19,994
nonzeros	79,966
structural full rank?	yes
structural rank	19,994
# of blocks from dmperm	3
# strongly connected comp.	3
entries not in dmperm blocks	0
explicit zero entries	0
nonzero pattern symmetry	symmetric
numeric value symmetry	symmetric
type	real
structure	symmetric
Cholesky candidate?	yes
positive definite?	yes

author	J. Lienemann, A. Greiner, J. Korvink
editor	E. Rudnyi
date	2004
kind	model reduction problem
2D/3D problem?	yes

Additional fields	size and type
M	sparse 19994-by-19994
E	sparse 19994-by-19994
B	sparse 19994-by-1
C	sparse 1-by-19994

Notes:

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

Ordering statistics:	AMD	METIS	DMPERM+
nnz(chol(P*(A+A'+s*I)*P'))	54,978	82,308	54,978
Cholesky flop count	1.6e+05	3.7e+05	1.6e+05
nnz(L+U), no partial pivoting	89,962	144,622	89,962
nnz(V) for QR, upper bound nnz(L) for LU	54,978	92,368	54,978
nnz(R) for QR, upper bound nnz(U) for LU	84,958	153,219	84,958

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.