Matrix properties
number of rows	19,998
number of columns	19,998
nonzeros	99,982
structural full rank?	yes
structural rank	19,998
# 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?	yes
positive definite?	yes

author	J. Lienemann, A. Greiner, J. Korvink
editor	E. Rudnyi
date	2004
kind	model reduction problem
2D/3D problem?	yes

Additional fields	size and type
M	sparse 19998-by-19998
E	sparse 19998-by-19998
B	sparse 19998-by-1
C	sparse 1-by-19998

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	69,988
Cholesky flop count	2.5e+05
nnz(L+U), no partial pivoting, with AMD	119,978
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	69,988
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	109,976

SVD-based statistics:
norm(A)	4.71123e+14
min(svd(A))	0.000228815
cond(A)	2.05897e+18
rank(A)	16,182
sprank(A)-rank(A)	3,816
null space dimension	3,816
full numerical rank?	no
singular value gap	1.00046

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.