Matrix properties
number of rows	21,498
number of columns	21,498
nonzeros	897,056
structural full rank?	yes
structural rank	21,498
# of blocks from dmperm	1
# strongly connected comp.	1
explicit zero entries	0
nonzero pattern symmetry	symmetric
numeric value symmetry	symmetric
type	integer
structure	symmetric
Cholesky candidate?	yes
positive definite?	no

author	R. Kouhia
editor	T. Davis
date	2008
kind	structural problem
2D/3D problem?	yes

Additional fields	size and type
b	full 21498-by-1

Notes:

Matrix problems from Reijo Kouhia, Structural Mechanics, Helsinki  
University of Technology.   http://users.tkk.fi/~kouhia/sparse.html

Ordering statistics:	result
nnz(chol(P*(A+A'+s*I)*P')) with AMD	2,251,690
Cholesky flop count	4.6e+08
nnz(L+U), no partial pivoting, with AMD	4,481,882
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	6,715,664
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	12,198,788

SVD-based statistics:
norm(A)	173.029
min(svd(A))	4.05471e-202
cond(A)	4.26735e+203
rank(A)	3,583
sprank(A)-rank(A)	17,915
null space dimension	17,915
full numerical rank?	no
singular value gap	8.4176e+09

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.