Matrix properties
number of rows	513,351
number of columns	513,351
nonzeros	20,207,907
structural full rank?	yes
structural rank	513,351
# of blocks from dmperm	46
# strongly connected comp.	46
explicit zero entries	144
nonzero pattern symmetry	symmetric
numeric value symmetry	symmetric
type	real
structure	symmetric
Cholesky candidate?	yes
positive definite?	yes

author	M. Mazaheri
editor	T. Davis
date	2015
kind	computer vision problem
2D/3D problem?	yes

Additional fields	size and type
b	full 513351-by-1

Notes:

Sparse bundle adjustment problem from Mehdi Mazaheri, University of Calgary   
                                                                              
A is symmetric positive definite, coming from bundle adjustment of 1700 images
to optimize the trajectory of a multi-camera data acqusition system. The      
trajectory is a loop inside a building at the University of Calgary.          
                                                                              
Mehdi Mazaheri                                                                
Dept of Geomatics, University of Calgary                                      

Ordering statistics:	result
nnz(chol(P*(A+A'+s*I)*P')) with AMD	10,659,339
Cholesky flop count	3.7e+08
nnz(L+U), no partial pivoting, with AMD	20,805,327
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	1,732,207,548
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	2,681,108,649

Note that all matrix statistics (except nonzero pattern symmetry) exclude the 144 explicit zero entries.

For a description of the statistics displayed above, click here.

Maintained by Tim Davis, last updated 04-Jun-2015.
Matrix pictures by cspy, a MATLAB function in the CSparse package.
Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.