Matrix properties
number of rows	80
number of columns	80
nonzeros	314
structural full rank?	yes
structural rank	80
# of blocks from dmperm	21
# strongly connected comp.	21
explicit zero entries	614
nonzero pattern symmetry	symmetric
numeric value symmetry	32%
type	real
structure	unsymmetric
Cholesky candidate?	no
positive definite?	no

author	R. Grimes
editor	I. Duff, R. Grimes, J. Lewis
date	1983
kind	computational fluid dynamics problem
2D/3D problem?	yes

Ordering statistics:	result
nnz(chol(P*(A+A'+s*I)*P')) with AMD	236
Cholesky flop count	7.4e+02
nnz(L+U), no partial pivoting, with AMD	392
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	203
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	424

Note that all matrix statistics (except nonzero pattern symmetry) exclude the 614 explicit zero entries.

SVD-based statistics:
norm(A)	1.73857e+10
min(svd(A))	0.348153
cond(A)	4.99369e+10
rank(A)	80
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 (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.