Andrews/Andrews graph

Matrix: Andrews/Andrews

Description: Eigenvalue problem, Stuart Andrews, Brown Univ. stu@cs.brown.edu


  • UF Sparse Matrix Collection
  • Matrix group: Andrews
  • Click here for a description of the Andrews group.
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  • download as a MATLAB mat-file, file size: 2 MB. Use UFget(924) or UFget('Andrews/Andrews') in MATLAB.
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    Andrews/Andrews

    Matrix properties
    number of rows60,000
    number of columns60,000
    nonzeros760,154
    structural full rank?yes
    structural rank60,000
    # of blocks from dmperm1
    # strongly connected comp.1
    entries not in dmperm blocks0
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typeinteger
    structuresymmetric
    Cholesky candidate?yes
    positive definite?yes

    authorS. Andrews
    editorT. Davis
    date2003
    kindcomputer graphics/vision problem
    2D/3D problem?yes

    Ordering statistics:AMD METIS
    nnz(chol(P*(A+A'+s*I)*P'))117,039,940 36,595,274
    Cholesky flop count5.8e+11 5.2e+10
    nnz(L+U), no partial pivoting234,019,880 73,130,548
    nnz(V) for QR, upper bound nnz(L) for LU241,984,349 82,685,669
    nnz(R) for QR, upper bound nnz(U) for LU420,425,913 159,203,547

    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.