Matrix properties
number of rows	15,435
number of columns	15,435
nonzeros	141,478
structural full rank?	yes
structural rank	15,435
# of blocks from dmperm	1
# strongly connected comp.	1
explicit zero entries	16,795
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 15435-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	100,254
Cholesky flop count	8.0e+05
nnz(L+U), no partial pivoting, with AMD	185,073
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	166,802
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	353,258

Note that all matrix statistics (except nonzero pattern symmetry) exclude the 16795 explicit zero entries.

SVD-based statistics:
norm(A)	108508
min(svd(A))	0.000191859
cond(A)	5.65559e+08
rank(A)	15,435
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.