Matrix properties
number of rows	22,692
number of columns	22,692
nonzeros	1,482,390
structural full rank?	yes
structural rank	22,692
# of blocks from dmperm	1
# strongly connected comp.	1
explicit zero entries	0
nonzero pattern symmetry	symmetric
numeric value symmetry	0%
type	complex
structure	symmetric
Cholesky candidate?	no
positive definite?	no

author	K. Meerbergen
editor	E. Rudnyi
date	2004
kind	model reduction problem
2D/3D problem?	yes

Additional fields	size and type
M	sparse 22692-by-22692
B	sparse 22692-by-1

Notes:

Primary matrix in this model reduction problem is the Oberwolfach K matrix

Ordering statistics:	result
nnz(chol(P*(A+A'+s*I)*P')) with AMD	8,698,416
Cholesky flop count	5.5e+09
nnz(L+U), no partial pivoting, with AMD	17,374,140
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	7,724,103
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	15,373,257

SVD-based statistics:
norm(A)	1.88708e+11
min(svd(A))	1.77817e-07
cond(A)	1.06125e+18
rank(A)	22,686
sprank(A)-rank(A)	6
null space dimension	6
full numerical rank?	no
singular value gap	4.92173e+06

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.