Matrix properties
number of rows	2,911,419
number of columns	2,911,419
nonzeros	127,729,899
structural full rank?	yes
structural rank	2,911,419
# of blocks from dmperm	58,990
# strongly connected comp.	58,990
explicit zero entries	0
nonzero pattern symmetry	symmetric
numeric value symmetry	symmetric
type	real
structure	symmetric
Cholesky candidate?	yes
positive definite?	yes

author	C. Janna, M. Ferronato
editor	T. Davis
date	2014
kind	2D/3D problem
2D/3D problem?	yes

Notes:

Janna/Bump_2911: 3D geomechanical reservoir simulation           
                                                                 
Authors: Carlo Janna and Massimiliano Ferronato                  
Symmetric Positive Definite Matrix                               
# equations:     2,911,419                                       
# non-zeroes:  130,378,257                                       
                                                                 
The matrix Bump_2911 is obtained from the 3D geomechanical       
simulation of a gas-reservoir discretized by linear tetrahedral  
Finite Elements. The mechanical properties of the medium vary    
with the depth and the geological formation. Zero displacement   
are applied on bottom and lateral boundary, while a traction-free
top boundary is assumed.                                         
                                                                 
Further information may be found in the following papers:        
                                                                 
1) C. Janna, M. Ferronato, G. Gambolati. "Enhanced Block FSAI    
preconditioning using Domain Decomposition techniques". SIAM     
Journal on Scientific Computing, 35, pp. S229-S249, 2013.        
                                                                 
2) C. Janna, M. Ferronato, G. Gambolati. "The use of supernodes  
in factored sparse approximate inverse preconditioning". SIAM    
Journal on Scientific Computing, submitted.                      

Ordering statistics:	result
nnz(chol(P*(A+A'+s*I)*P')) with AMD	46,256,036,210
Cholesky flop count	4.0e+15
nnz(L+U), no partial pivoting, with AMD	92,509,161,001
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	59,141,190,270
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	99,758,707,809

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.