Matrix properties
number of rows	18,696
number of columns	18,696
nonzeros	4,396,289
structural full rank?	yes
structural rank	18,696
# of blocks from dmperm	221
# strongly connected comp.	221
explicit zero entries	0
nonzero pattern symmetry	0%
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 18696-by-339

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	10,516,757
Cholesky flop count	6.9e+09
nnz(L+U), no partial pivoting, with AMD	21,014,818
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	1,497,631
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	11,056,947

SVD-based statistics:
norm(A)	151252
min(svd(A))	2.49489e-05
cond(A)	6.06246e+09
rank(A)	18,696
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.