Matrix properties
number of rows	11,445
number of columns	11,445
nonzeros	176,117
structural full rank?	yes
structural rank	11,445
# 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	E. Rudnyi
editor	E. Rudnyi
date	2004
kind	model reduction problem
2D/3D problem?	yes

Additional fields	size and type
E	sparse 11445-by-11445
B	sparse 11445-by-1
C	sparse 7-by-11445
cname	full 7-by-7

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	491,255
Cholesky flop count	4.1e+07
nnz(L+U), no partial pivoting, with AMD	971,065
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	841,710
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	2,001,083

SVD-based statistics:
norm(A)	266.266
min(svd(A))	2.741e-15
cond(A)	9.71418e+16
rank(A)	11,444
sprank(A)-rank(A)	1
null space dimension	1
full numerical rank?	no
singular value gap	5.96041e+07

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.