Matrix properties
number of rows	30,798
number of columns	30,798
nonzeros	1,801,300
structural full rank?	yes
structural rank	30,798
# 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 30798-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	7,218,099
Cholesky flop count	4.2e+09
nnz(L+U), no partial pivoting, with AMD	14,405,400
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	95,554,020
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	133,074,773

SVD-based statistics:
norm(A)	101234
min(svd(A))	5.3523e-10
cond(A)	1.89141e+14
rank(A)	30,231
sprank(A)-rank(A)	567
null space dimension	567
full numerical rank?	no
singular value gap	1.00126

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.