Matrix properties
number of rows	20
number of columns	15
nonzeros	60
structural full rank?	yes
structural rank	15
# of blocks from dmperm	1
# strongly connected comp.	1
explicit zero entries	0
nonzero pattern symmetry	0%
numeric value symmetry	0%
type	integer
structure	rectangular
Cholesky candidate?	no
positive definite?	no

author	V. Welker
editor	J.-G. Dumas
date	2008
kind	combinatorial problem
2D/3D problem?	no

Notes:

Simplicial complexes from Homology from Volkmar Welker.     
From Jean-Guillaume Dumas' Sparse Integer Matrix Collection,
http://ljk.imag.fr/membres/Jean-Guillaume.Dumas/simc.html   
                                                            
http://www.mathematik.uni-marburg.de/~welker/               
                                                            
Filename in JGD collection: Homology/n3c4.b2.20x15.sms      

Ordering statistics:	result
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	123
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	105

SVD-based statistics:
norm(A)	2.44949
min(svd(A))	1.29148e-16
cond(A)	1.89666e+16
rank(A)	10
sprank(A)-rank(A)	5
null space dimension	5
full numerical rank?	no
singular value gap	3.8646e+15

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.