Matrix: GHS_indef/spmsrtls

Description: Gould, Hu, & Scott: sparse matrix square root (CUTEr)

GHS_indef/spmsrtls graph
(undirected graph drawing)

GHS_indef/spmsrtls

  • Home page of the UF Sparse Matrix Collection
  • Matrix group: GHS_indef
  • Click here for a description of the GHS_indef 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: 1 MB. Use UFget(1309) or UFget('GHS_indef/spmsrtls') in MATLAB.
  • download in Matrix Market format, file size: 2 MB.
  • download in Rutherford/Boeing format, file size: 1 MB.

    Matrix properties
    number of rows29,995
    number of columns29,995
    nonzeros229,947
    structural full rank?yes
    structural rank29,995
    # of blocks from dmperm1
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typereal
    structuresymmetric
    Cholesky candidate?no
    positive definite?no

    authorN. Gould
    editorN. Gould
    date2004
    kindstatistical/mathematical problem
    2D/3D problem?no

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD129,971
    Cholesky flop count5.7e+05
    nnz(L+U), no partial pivoting, with AMD229,947
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD129,979
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD219,942

    SVD-based statistics:
    norm(A)14.656
    min(svd(A))0.000103465
    cond(A)141651
    rank(A)29,995
    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

    GHS_indef/spmsrtls 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.