Matrix properties
number of rows	1,176
number of columns	1,176
nonzeros	18,552
structural full rank?	yes
structural rank	1,176
# of blocks from dmperm	2
# strongly connected comp.	2
explicit zero entries	0
nonzero pattern symmetry	symmetric
numeric value symmetry	symmetric
type	binary
structure	symmetric
Cholesky candidate?	yes
positive definite?	no

author	A. Erisman
editor	A. Curtis, I. Duff, J. Reid
date	1973
kind	power network problem
2D/3D problem?	no

Ordering statistics:	result
nnz(chol(P*(A+A'+s*I)*P')) with AMD	10,483
Cholesky flop count	3.2e+05
nnz(L+U), no partial pivoting, with AMD	19,790
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	11,822
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	27,455

SVD-based statistics:
norm(A)	80.0739
min(svd(A))	0
cond(A)	Inf
rank(A)	774
sprank(A)-rank(A)	402
null space dimension	402
full numerical rank?	no
singular value gap	1.43856e+12

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.