Matrix properties
number of rows	1,434
number of columns	1,434
nonzeros	18,228
structural full rank?	yes
structural rank	1,434
# of blocks from dmperm	30
# strongly connected comp.	30
explicit zero entries	0
nonzero pattern symmetry	symmetric
numeric value symmetry	symmetric
type	real
structure	symmetric
Cholesky candidate?	no
positive definite?	no

author	J. Li, M. Kamon
editor	E. Rudnyi
date	2006
kind	model reduction problem
2D/3D problem?	yes

Additional fields	size and type
E	sparse 1434-by-1434
B	sparse 1434-by-1

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	9,856
Cholesky flop count	1.7e+05
nnz(L+U), no partial pivoting, with AMD	18,278
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	18,782
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	35,555

SVD-based statistics:
norm(A)	913.606
min(svd(A))	0.00233754
cond(A)	390841
rank(A)	1,434
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.