Matrix properties
number of rows	73,159
number of columns	59,498
nonzeros	647,495
structural full rank?	no
structural rank	42,208
# of blocks from dmperm	3,546
# strongly connected comp.	27,546
explicit zero entries	0
nonzero pattern symmetry	0%
numeric value symmetry	0%
type	real
structure	rectangular
Cholesky candidate?	no
positive definite?	no

author	T. Clark
editor	T. Davis
date	2009
kind	computer graphics/vision problem
2D/3D problem?	yes

Additional fields	size and type
b	full 73159-by-1

Notes:

Tomographic reconstruction of a particle field in fluid flow, T. Clark  
See http://www.mathworks.com/matlabcentral/newsreader/view_thread/254747
for a discussion.  The problem can be solved via lsqlin in MATLAB:      
lb = zeros (n,1) ;                                                      
x = lsqlin (A, b, [ ], [ ], [ ], [ ], lb) ;                             

Ordering statistics:	result
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	11,451,626
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	213,665,278

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.