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

  • Matrix: Nemeth/nemeth18
  • Description: Newton-Schultz iteration, Z_k+1=Z_k+(1/2)*(I-(Z_k)^2)*Z_k. This is Z_18
  • download as a MATLAB mat-file, file size: 5 MB. Use UFget(782) or UFget('Nemeth/nemeth18') in MATLAB.
  • download in Matrix Market format
  • download in Rutherford/Boeing format

    Nemeth/nemeth18

    Nemeth/nemeth18 graph

    Matrix properties
    number of rows9,506
    number of columns9,506
    nonzeros695,234
    structural full rank?yes
    structural rank9,506
    # of blocks from dmperm1
    # strongly connected comp.1
    entries not in dmperm blocks0
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typereal
    structuresymmetric
    Cholesky candidate?no
    positive definite?no

    authorK. Nemeth
    editorT. Davis
    date1999
    kindsubsequent theoretical/quantum chemistry problem
    2D/3D problem?no

    Notes:

    next: Nemeth/nemeth19 first: Nemeth/nemeth01

    Ordering statistics:AMD METIS
    nnz(chol(P*(A+A'+s*I)*P'))382,022 842,491
    Cholesky flop count1.5e+07 7.8e+07
    nnz(L+U), no partial pivoting754,538 1,675,476
    nnz(V) for QR, upper bound nnz(L) for LU383,290 971,269
    nnz(R) for QR, upper bound nnz(U) for LU751,356 1,653,161

    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.