Matrix properties
number of rows	1,357
number of columns	1,357
nonzeros	8,985
structural full rank?	yes
structural rank	1,357
# 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 1357-by-1357
B	sparse 1357-by-7
C	sparse 6-by-1357

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	11,629
Cholesky flop count	1.4e+05
nnz(L+U), no partial pivoting, with AMD	21,901
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	20,824
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	42,242

SVD-based statistics:
norm(A)	4.80077e-05
min(svd(A))	3.611e-09
cond(A)	13294.8
rank(A)	1,357
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.