Matrix: Cylshell/s2rmq4m1

Description: FEM, cylindrical shell, 30x30 quad. mesh, stabilized MITC4 elements, R/t=100

Cylshell/s2rmq4m1 graph
(undirected graph drawing)


Cylshell/s2rmq4m1
Cylshell/s2rmq4m1 graph

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  • Matrix group: Cylshell
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  • download as a MATLAB mat-file, file size: 1 MB. Use UFget(1606) or UFget('Cylshell/s2rmq4m1') in MATLAB.
  • download in Matrix Market format, file size: 1 MB.
  • download in Rutherford/Boeing format, file size: 854 KB.

    Matrix properties
    number of rows5,489
    number of columns5,489
    nonzeros263,351
    structural full rank?yes
    structural rank5,489
    # of blocks from dmperm1
    # strongly connected comp.1
    explicit zero entries17,760
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typereal
    structuresymmetric
    Cholesky candidate?yes
    positive definite?yes

    authorR. Kouhia
    editorR. Boisvert, R. Pozo, K. Remington, B. Miller, R. Lipman, R. Barrett, J. Dongarra
    date1997
    kindstructural problem
    2D/3D problem?yes

    Additional fieldssize and type
    coordfull 5489-by-3

    Notes:

    %                                                                              
    %FILE  s2rmq4m1.mtx                                                            
    %TITLE Cyl shell R/t = 100 unif 30x30 quad mesh stab MITC4 elem with drill rot 
    %KEY   s2rmq4m1                                                                
    %                                                                              
    %                                                                              
    %CONTRIBUTOR Reijo Kouhia (reijo.kouhia@hut.fi)                                
    %                                                                              
    %REFERENCE   M. Benzi, R. Kouhia, M.Tuma: An assesment of some                 
    %            preconditioning techniques in shell problems                      
    %            Technical Report LA-UR-97-3892, Los Alamos National Laboratory    
    %                                                                              
    %BEGIN DESCRIPTION                                                             
    % Matrix from a static analysis of a cylindrical shell                         
    % Radius to thickness ratio R/t = 100                                          
    % Length to radius ratio    R/L = 1                                            
    % One octant discretized with uniform 30 x 30 quadrilateral 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 2x2 Gauss-Legendre 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:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD927,079
    Cholesky flop count2.3e+08
    nnz(L+U), no partial pivoting, with AMD1,848,669
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD854,951
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD1,697,963

    Note that all matrix statistics (except nonzero pattern symmetry) exclude the 17760 explicit zero entries.

    SVD-based statistics:
    norm(A)68743.4
    min(svd(A))0.000387463
    cond(A)1.77419e+08
    rank(A)5,489
    sprank(A)-rank(A)0
    null space dimension0
    full numerical rank?yes

    singular values (MAT file):click here
    SVD method used:s = svd (full (A)) ;
    status:ok

    Cylshell/s2rmq4m1 svd

    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.