Matrix properties
number of rows	8,140
number of columns	8,140
nonzeros	2,012,833
structural full rank?	yes
structural rank	8,140
# of blocks from dmperm	2
# strongly connected comp.	2
explicit zero entries	4,069
nonzero pattern symmetry	symmetric
numeric value symmetry	symmetric
type	real
structure	symmetric
Cholesky candidate?	no
positive definite?	no

author	L. Peijie
editor	J. Hogg
date	2011
kind	power network problem
2D/3D problem?	no

Additional fields	size and type
b	full 8140-by-1

Notes:

Three different kinds of optimization methods (OPF, TSCOPF, HTC)
applied to power system simulation.  All matrices are symmetric 
indefinite.  From Li Peijie, Institute of Power Systems,        
Guangxi University (beyondpeijie at gxu.edu.cn).  Collected by  
Jonathan Hogg, Rutherford Appleton Laboratory, Oxfordshire, UK. 

Ordering statistics:	result
nnz(chol(P*(A+A'+s*I)*P')) with AMD	2,483,695
Cholesky flop count	2.3e+09
nnz(L+U), no partial pivoting, with AMD	4,959,250
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	3,241,745
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	6,638,511

Note that all matrix statistics (except nonzero pattern symmetry) exclude the 4069 explicit zero entries.

SVD-based statistics:
norm(A)	41293.3
min(svd(A))	1.25023e-05
cond(A)	3.30284e+09
rank(A)	8,140
sprank(A)-rank(A)	0
null space dimension	0
full numerical rank?	yes

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.