Matrix properties
number of rows	1,668
number of columns	1,668
nonzeros	10,750
structural full rank?	yes
structural rank	1,668
# 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	D. Hohlfield, T. Bechtold, H. Zappe
editor	E. Rudnyi
date	2006
kind	model reduction problem
2D/3D problem?	yes

Additional fields	size and type
E	sparse 1668-by-1668
B	sparse 1668-by-1
C	sparse 5-by-1668
cname	full 5-by-5

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	22,483
Cholesky flop count	5.8e+05
nnz(L+U), no partial pivoting, with AMD	43,298
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	35,461
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	65,784

SVD-based statistics:
norm(A)	0.000173298
min(svd(A))	3.47945e-09
cond(A)	49806.2
rank(A)	1,668
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.