• UF Sparse Matrix Collection
  • Matrix group: GHS_psdef
  • Click here for a description of the GHS_psdef group.
  • Click here for a list of all matrices
  • Click here for a list of all matrix groups


  • Matrix: GHS_psdef/ldoor
  • Description: INDEED Test Matrix
  • download as a MATLAB mat-file, file size: 308 MB. Use UFget(1268) or UFget('GHS_psdef/ldoor') in MATLAB.
  • download in Matrix Market format
  • download in Rutherford/Boeing format

    GHS_psdef/ldoor

    dmperm of GHS_psdef/ldoor

    GHS_psdef/ldoor graph

    Matrix properties
    number of rows952,203
    number of columns952,203
    nonzeros42,493,817
    structural full rank?yes
    structural rank952,203
    # of blocks from dmperm42,667
    # strongly connected comp.42,667
    entries not in dmperm blocks0
    explicit zero entries4,028,658
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typereal
    structuresymmetric
    Cholesky candidate?yes
    positive definite?yes

    authorJ. Weiher
    editorJ. Koster
    date2004
    kindstructural problem
    2D/3D problem?yes

    Ordering statistics:AMD METIS DMPERM+
    nnz(chol(P*(A+A'+s*I)*P'))141,363,607 130,705,577 -
    Cholesky flop count1.1e+11 6.5e+10 -
    nnz(L+U), no partial pivoting281,775,011 260,458,951 -
    nnz(V) for QR, upper bound nnz(L) for LU493,926,414 292,334,386 -
    nnz(R) for QR, upper bound nnz(U) for LU1,038,324,331 590,390,040 -

    Note that all matrix statistics (except nonzero pattern symmetry) exclude the 4028658 explicit zero entries.

    Maintained by Tim Davis, last updated 04-May-2008.
    Matrix pictures by cspy, a MATLAB function in the CSparse package.
    Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.