Matrix properties
number of rows	29,902
number of columns	29,902
nonzeros	274,697
structural full rank?	yes
structural rank	29,902
# of blocks from dmperm	1
# strongly connected comp.	1
explicit zero entries	27,721
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 29902-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	211,402
Cholesky flop count	2.2e+06
nnz(L+U), no partial pivoting, with AMD	392,902
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	370,626
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	809,882

Note that all matrix statistics (except nonzero pattern symmetry) exclude the 27721 explicit zero entries.

SVD-based statistics:
norm(A)	6.66667e+07
min(svd(A))	0.000695993
cond(A)	9.57865e+10
rank(A)	29,902
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.