Matrix properties
number of rows	28,216
number of columns	28,216
nonzeros	730,080
structural full rank?	yes
structural rank	28,216
# of blocks from dmperm	2
# strongly connected comp.	2
explicit zero entries	0
nonzero pattern symmetry	symmetric
numeric value symmetry	symmetric
type	real
structure	symmetric
Cholesky candidate?	no
positive definite?	no

author	G. Geng
editor	T. Davis
date	2009
kind	power network problem
2D/3D problem?	no

Additional fields	size and type
b	sparse 28216-by-1

Notes:

Transient stability-constrained optimal power flow (TSOPF) problems from     
Guangchao Geng, Institute of Power System, College of Electrical Engineering,
Zhejiang University, Hangzhou, 310027, China.  (genggc AT gmail DOT com).    
Matrices in the  Full-Space (FS) group are symmetric indefinite, and are best
solved with MA57.  Matrices in the the Reduced-Space (RS) group are best     
solved with KLU, which for these matrices can be 10 times faster than UMFPACK
or SuperLU.                                                                  

Ordering statistics:	result
nnz(chol(P*(A+A'+s*I)*P')) with AMD	1,995,246
Cholesky flop count	2.9e+08
nnz(L+U), no partial pivoting, with AMD	3,962,276
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	66,537,663
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	107,036,016

SVD-based statistics:
norm(A)	24506.4
min(svd(A))	7.85749e-10
cond(A)	3.11885e+13
rank(A)	28,017
sprank(A)-rank(A)	199
null space dimension	199
full numerical rank?	no
singular value gap	1.00378

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.