Matrix properties
number of rows	20,374
number of columns	20,374
nonzeros	812,749
structural full rank?	yes
structural rank	20,374
# of blocks from dmperm	426
# strongly connected comp.	426
explicit zero entries	0
nonzero pattern symmetry	3%
numeric value symmetry	0%
type	real
structure	unsymmetric
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 20374-by-49

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	1,840,401
Cholesky flop count	1.8e+08
nnz(L+U), no partial pivoting, with AMD	3,660,428
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	247,082
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	1,924,721

SVD-based statistics:
norm(A)	2365.05
min(svd(A))	2.74908e-05
cond(A)	8.60307e+07
rank(A)	20,374
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 (R)) ; where [~,R,E] = spqr (A) with droptol of zero
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.