Matrix properties
number of rows	5,177
number of columns	5,177
nonzeros	35,185
structural full rank?	yes
structural rank	5,177
# of blocks from dmperm	1
# strongly connected comp.	1
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 5177-by-5177
B	sparse 5177-by-7
C	sparse 6-by-5177

Notes:

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

Ordering statistics:	result
nnz(chol(P*(A+A'+s*I)*P')) with AMD	61,746
Cholesky flop count	1.4e+06
nnz(L+U), no partial pivoting, with AMD	118,315
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	128,813
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	276,474

SVD-based statistics:
norm(A)	4.99224e-05
min(svd(A))	9.35911e-10
cond(A)	53341
rank(A)	5,177
sprank(A)-rank(A)	0
null space dimension	0
full numerical rank?	yes

singular values (MAT file):	click here
SVD method used:	s = svd (full (A)) ;
status:	ok

For a description of the statistics displayed above, click here.

Maintained by Tim Davis, last updated 12-Mar-2014.
Matrix pictures by cspy, a MATLAB function in the CSparse package.
Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.