Matrix properties
number of rows	5,489
number of columns	5,489
nonzeros	217,669
structural full rank?	yes
structural rank	5,489
# of blocks from dmperm	1
# strongly connected comp.	1
entries not in dmperm blocks	0
explicit zero entries	1,852
nonzero pattern symmetry	symmetric
numeric value symmetry	symmetric
type	real
structure	symmetric
Cholesky candidate?	yes
positive definite?	yes

author	R. Kouhia
editor	R. Boisvert, R. Pozo, K. Remington, B. Miller, R. Lipman, R. Barrett, J. Dongarra
date	1997
kind	structural problem
2D/3D problem?	yes

Notes:

%                                                                              
%FILE  s3rmt3m1.mtx                                                            
%TITLE Cyl shell R/t=1000 unif 30x30 trian mesh stab MITC3 elem with drill rot 
%KEY   s3rmt3m1                                                                
%                                                                              
%                                                                              
%CONTRIBUTOR Reijo Kouhia (reijo.kouhia@hut.fi)                                
%                                                                              
%BEGIN DESCRIPTION                                                             
% Matrix from a static analysis of a cylindrical shell                         
% Radius to thickness ratio R/t = 1000                                         
% Length to radius ratio    R/L = 1                                            
% One octant discretized with uniform 30 x 30 triangular mesh                  
% element:                                                                     
% facet-type shell element where the bending part is formulated                
% using the stabilized MITC theory (stabilization paramater 0.4)               
% the membrane part includes drilling rotations using                          
% the Hughes-Brezzi formulation with (regularizing parameter = G/1000,         
% where G is the shear modulus)                                                
% full 3-point integration                                                     
% --------------------------------------------------------------------------   
% Note:                                                                        
% The sparsity pattern of the matrix is determined from the element            
% connectivity data assuming that the element matrix is full.                  
% Since this case the  material model is linear isotropically elastic          
% and the FE mesh is  uniform there exist some zeros.                          
% Since the removal of those zero elements is trivial                          
% but the reconstruction of the current sparsity                               
% pattern is impossible from the sparsified structure without any further      
% knowledge of the element connectivity, the zeros are retained in this file.  
% ---------------------------------------------------------------------------  
%END DESCRIPTION                                                               
%                                                                              
%                                                                              

Ordering statistics:	AMD	METIS
nnz(chol(P*(A+A'+s*I)*P'))	517,528	593,918
Cholesky flop count	7.2e+07	9.3e+07
nnz(L+U), no partial pivoting	1,029,567	1,182,347
nnz(V) for QR, upper bound nnz(L) for LU	665,211	809,852
nnz(R) for QR, upper bound nnz(U) for LU	1,314,023	1,496,012

Note that all matrix statistics (except nonzero pattern symmetry) exclude the 1852 explicit zero entries.

Maintained by Tim Davis, last updated 30-Sep-2008.
Matrix pictures by cspy, a MATLAB function in the CSparse package.
Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.