Matrix properties
number of rows	416,800
number of columns	416,800
nonzeros	17,277,420
structural full rank?	yes
structural rank	416,800
# of blocks from dmperm	84,321
# strongly connected comp.	84,321
explicit zero entries	5,044,916
nonzero pattern symmetry	symmetric
numeric value symmetry	1%
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:      416,800                                       
# non-zeroes:   22,322,336                                      
                                                                
Problem description: Fully coupled poroelastic problem          
(structural problem)                                            
                                                                
                                                                
The matrix CoupCons3D has been obtained through a Finite Element
transient simulation of a fully coupled consolidation problem on
a three-dimensional domain using Finite Differences for the     
discretization in time.                                         
                                                                
Further information can be found in the following papers:       
                                                                
1) M. Ferronato, G. Pini, and G. Gambolati. The role of         
preconditioning in the solution to FE coupled consolidation     
equations by Krylov subspace methods.  International Journal for
Numerical and Analytical Methods in Geomechanics 33 (2009), pp. 
405-423.                                                        
                                                                
2) M. Ferronato, C. Janna, and G. Pini. Parallel solution to    
ill-conditioned FE geomechanical problems. International Journal
for Numerical and Analytical Methods in Geomechanics 36 (2012), 
pp. 422-437.                                                    
                                                                
3) 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	255,454,187
Cholesky flop count	7.1e+11
nnz(L+U), no partial pivoting, with AMD	510,491,574
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	382,662,721
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	716,433,504

Note that all matrix statistics (except nonzero pattern symmetry) exclude the 5044916 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.