Clark/tomographic1

Tomographic reconstruction of a particle field in fluid flow, T. Clark
Name tomographic1
Group Clark
Matrix ID 2264
Num Rows 73,159
Num Cols 59,498
Nonzeros 647,495
Pattern Entries 647,495
Kind Computer Graphics/Vision Problem
Symmetric No
Date 2009
Author T. Clark
Editor T. Davis
Structural Rank 42,208
Structural Rank Full false
Num Dmperm Blocks 3,546
Strongly Connect Components 27,546
Num Explicit Zeros 0
Pattern Symmetry 0%
Numeric Symmetry 0%
Cholesky Candidate no
Positive Definite no
Type real
Download MATLAB Rutherford Boeing Matrix Market
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) ;