Matrix properties
number of rows	19,994
number of columns	19,994
nonzeros	79,966
structural full rank?	yes
structural rank	19,994
# of blocks from dmperm	3
# strongly connected comp.	3
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 19994-by-19994
E	sparse 19994-by-19994
B	sparse 19994-by-1
C	sparse 1-by-19994

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	54,978
Cholesky flop count	1.6e+05
nnz(L+U), no partial pivoting, with AMD	89,962
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	54,978
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	84,958

SVD-based statistics:
norm(A)	5.88727e+13
min(svd(A))	0.000114704
cond(A)	5.13256e+17
rank(A)	18,047
sprank(A)-rank(A)	1,947
null space dimension	1,947
full numerical rank?	no
singular value gap	1.0006

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.