Matrix properties
number of rows	20,685
number of columns	20,685
nonzeros	2,454,957
structural full rank?	yes
structural rank	20,685
# of blocks from dmperm	1
# strongly connected comp.	1
explicit zero entries	0
nonzero pattern symmetry	symmetric
numeric value symmetry	symmetric
type	binary
structure	symmetric
Cholesky candidate?	yes
positive definite?	no

author	C. Damhaug
editor	N. Gould, Y. Hu, J. Scott
date	2004
kind	structural problem
2D/3D problem?	yes

Ordering statistics:	result
nnz(chol(P*(A+A'+s*I)*P')) with AMD	6,409,887
Cholesky flop count	3.6e+09
nnz(L+U), no partial pivoting, with AMD	12,799,089
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	10,485,024
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	24,503,550

SVD-based statistics:
norm(A)	126.227
min(svd(A))	0
cond(A)	Inf
rank(A)	2,866
sprank(A)-rank(A)	17,819
null space dimension	17,819
full numerical rank?	no
singular value gap	7.12873e+10

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.