Matrix properties
number of rows	20,082
number of columns	20,082
nonzeros	281,150
structural full rank?	yes
structural rank	20,082
# of blocks from dmperm	1
# strongly connected comp.	1
explicit zero entries	0
nonzero pattern symmetry	symmetric
numeric value symmetry	9%
type	real
structure	unsymmetric
Cholesky candidate?	no
positive definite?	no

author	C. Moosmann, A. Griener
editor	E. Rudnyi
date	2004
kind	model reduction problem
2D/3D problem?	yes

Additional fields	size and type
E	sparse 20082-by-20082
B	sparse 20082-by-1
C	sparse 5-by-20082
cname	full 5-by-6

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	6,111,848
Cholesky flop count	5.0e+09
nnz(L+U), no partial pivoting, with AMD	12,203,614
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	8,897,575
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	16,070,062

SVD-based statistics:
norm(A)	0.314457
min(svd(A))	8.85393e-08
cond(A)	3.55161e+06
rank(A)	20,082
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 (R)) ; where [~,R,E] = spqr (A) with droptol of zero
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.