Matrix properties
number of rows	36,519
number of columns	36,519
nonzeros	326,107
structural full rank?	yes
structural rank	36,519
# of blocks from dmperm	57
# strongly connected comp.	57
explicit zero entries	0
nonzero pattern symmetry	symmetric
numeric value symmetry	symmetric
type	binary
structure	symmetric
Cholesky candidate?	yes
positive definite?	no

author	NASA
editor	G. Kumfert, A. Pothen
date	1995
kind	duplicate structural problem
2D/3D problem?	yes

Notes:

Nasa/pwt, GHS_psdef/pwt and Pothen/pwt are identical; Pothen/ has xyz coord.

Ordering statistics:	result
nnz(chol(P*(A+A'+s*I)*P')) with AMD	1,555,833
Cholesky flop count	1.6e+08
nnz(L+U), no partial pivoting, with AMD	3,075,147
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	2,667,503
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	5,000,519

SVD-based statistics:
norm(A)	9.90527
min(svd(A))	8.72467e-19
cond(A)	1.13532e+19
rank(A)	35,475
sprank(A)-rank(A)	1,044
null space dimension	1,044
full numerical rank?	no
singular value gap	4.30451e+09

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.