Matrix: AG-Monien/grid1

Description: 2D finite element problem

AG-Monien/grid1 graph
(undirected graph drawing)


AG-Monien/grid1 dmperm of AG-Monien/grid1
AG-Monien/grid1 graph

  • Home page of the UF Sparse Matrix Collection
  • Matrix group: AG-Monien
  • Click here for a description of the AG-Monien group.
  • Click here for a list of all matrices
  • Click here for a list of all matrix groups
  • download as a MATLAB mat-file, file size: 5 KB. Use UFget(2416) or UFget('AG-Monien/grid1') in MATLAB.
  • download in Matrix Market format, file size: 3 KB.
  • download in Rutherford/Boeing format, file size: 3 KB.

    Matrix properties
    number of rows252
    number of columns252
    nonzeros952
    structural full rank?yes
    structural rank252
    # of blocks from dmperm2
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typebinary
    structuresymmetric
    Cholesky candidate?no
    positive definite?no

    authorR. Diekmann, R. Preis
    editorR. Diekmann, R. Preis
    date1998
    kind2D/3D problem
    2D/3D problem?yes

    Additional fieldssize and type
    coordfull 252-by-2

    Notes:

    AG-Monien Graph Collection, Ralf Diekmann and Robert Preis                     
    http://www2.cs.uni-paderborn.de/fachbereich/AG/monien/RESEARCH/PART/graphs.html
                                                                                   
    A collection of test graphs from various sources.  Many of the graphs          
    include XY or XYZ coordinates.  This set also includes some graphs from        
    the Harwell-Boeing collection, the NASA matrices, and some random matrices     
    which are not included here in the AG-Monien/ group of the UF Collection.      
    In addition, two graphs already appear in other groups:                        
                                                                                   
       AG-Monien/big : same as Nasa/barth5, Pothen/barth5 (not included here)      
       AG-Monien/cage_3_11 : same as Pajek/GD98_c (included here)                  
                                                                                   
    The AG-Monien/GRID subset is not included.  It contains square grids that      
    are already well-represented in the UF Collection.                             
                                                                                   
    Six of the problem sets are included as sequences, each sequence being         
    a single problem instance in the UF Collection:                                
                                                                                   
       bfly:  10 butterfly graphs 3..12                                            
       cage:  45 cage graphs 3..12                                                 
       cca:   10 cube-connected cycle graphs, no wrap                              
       ccc:   10 cube-connected cycle graphs, with wrap                            
       debr:  18 De Bruijn graphs                                                  
       se:    13 shuffle-exchange graphs                                           
                                                                                   
    Problem.aux.G{:} are the graphs in these 6 sequences.  Problem.aux.Gname{:}    
    are the original names of each graph, and Problemm.aux.Gcoord{:} are the       
    xy or xyz coordinates of each node, if present.                                
    

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD2,228
    Cholesky flop count2.7e+04
    nnz(L+U), no partial pivoting, with AMD4,204
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD1,771
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD3,087

    SVD-based statistics:
    norm(A)3.91703
    min(svd(A))1.16051e-16
    cond(A)3.37527e+16
    rank(A)250
    sprank(A)-rank(A)2
    null space dimension2
    full numerical rank?no
    singular value gap5.5305e+13

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

    AG-Monien/grid1 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.