Matrix properties
number of rows	1,504,002
number of columns	1,504,002
nonzeros	110,686,677
structural full rank?	yes
structural rank	1,504,002
# of blocks from dmperm	4,502
# strongly connected comp.	4,502
explicit zero entries	193,295
nonzero pattern symmetry	symmetric
numeric value symmetry	0%
type	real
structure	unsymmetric
Cholesky candidate?	no
positive definite?	no

author	C. Janna, M. Ferronato, G. Pini
editor	T. Davis
date	2012
kind	structural problem
2D/3D problem?	yes

Notes:

Authors: Carlo Janna, Massimiliano Ferronato, Giorgio Pini        
Matrix type: Unsymmetric                                          
# equations:      1,504,002                                       
# non-zeroes:   110,879,972                                       
                                                                  
Problem description: Poroelastic problem (structural problem)     
                                                                  
The matrix ML_Geer has been obtained to find through a Meshless   
Petrov-Galerkin discretization the deformed configuration of an   
axial-symmetric porous medium subject to a pore-pressure drawdown.
                                                                  
Further information can be found in the following papers:         
                                                                  
1) M. Ferronato, A. Mazzia, G. Pini, and G. Gambolati. A meshless 
method for axi-symmetric poroelastic simulations: numerical       
study. International Journal for Numerical Methods in Engineering 
70 (2007), pp. 1346-1365.                                         
                                                                  
2) M. Ferronato, C. Janna and G. Pini. A generalized Block FSAI   
preconditioner for unsymmetric indefinite matrices. Journal of    
Computational and Applied Mathematics (2012), submitted.          

Ordering statistics:	result
nnz(chol(P*(A+A'+s*I)*P')) with AMD	1,563,946,213
Cholesky flop count	5.5e+12
nnz(L+U), no partial pivoting, with AMD	3,126,388,424
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	2,826,763,264
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	5,505,743,223

Note that all matrix statistics (except nonzero pattern symmetry) exclude the 193295 explicit zero entries.

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.