Matrix properties
number of rows	49,989
number of columns	49,989
nonzeros	444,851
structural full rank?	yes
structural rank	49,989
# of blocks from dmperm	7
# strongly connected comp.	7
explicit zero entries	54,156
nonzero pattern symmetry	symmetric
numeric value symmetry	symmetric
type	real
structure	symmetric
Cholesky candidate?	no
positive definite?	no

author	IBM
editor	O. Schenk
date	2006
kind	subsequent optimization problem
2D/3D problem?	no

Additional fields	size and type
b	full 49989-by-1

Notes:

next: - first: Schenk_IBMNA/c-66                                       
An earlier version (Oct. 2003) of this matrix was obtained from Olaf   
Schenk, and appears here as Schenk_IBMNA/c-66.  However, it differs    
from the version posted on his web site as of Nov. 2006.   The new     
version appears here as Schenk_IBMNA/c-66b.   The two matrices are very
similar, but not identical.                                            

Ordering statistics:	result
nnz(chol(P*(A+A'+s*I)*P')) with AMD	1,009,418
Cholesky flop count	2.7e+08
nnz(L+U), no partial pivoting, with AMD	1,968,847
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	79,558,462
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	174,206,767

Note that all matrix statistics (except nonzero pattern symmetry) exclude the 54156 explicit zero entries.

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.