• SJSU Singular Matrix Database
  • Matrix group: Andrianov
  • Click here for a description of the Andrianov group.
  • Click here for a list of all matrices
  • Click here for a list of all matrix groups

  • Matrix: Andrianov/net4-1
  • Description: net4-1 matrix from Alexander Andrianov, SAS Institute Inc.
  • download as a MATLAB mat-file, file size: 3 MB. Use SJget(472) or SJget('Andrianov/net4-1') in MATLAB.
  • download in Matrix Market format, file size: 3 MB.
  • download in Rutherford/Boeing format, file size: 1 MB.


    A singular value of A is guaranteed1 to be in the interval pictured by the blue bars around each of the calculated singular values.

    Routine svds_err, version 1.0, used with Matlab (R2008a) to calculate the 6 largest singular values and associated error bounds.
    Routine spnrank, version 1.0 with opts.tol_eigs = 1e-008, used with Matlab (R2008a) to calculate singular values 86174 to 86179 and associated error bounds.


    dmperm of Andrianov/net4-1

    Matrix properties (click for a legend)  
    number of rows88,343
    number of columns88,343
    structural full rank?yes
    structural rank88,343
    numerical rank 86,176
    dimension of the numerical null space2,167
    numerical rank / min(size(A))0.97547
    Euclidean norm of A 145.02
    calculated singular value # 861764.0257e-005
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    calculated singular value # 861773.651e-014
    gap in the singular values at the numerical rank:
    singular value # 86176 / singular value # 86177
    calculated condition number-2
    # of blocks from dmperm97
    # strongly connected comp.97
    entries not in dmperm blocks0
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    Cholesky candidate?yes
    positive definite?no

    authorA. Andrianov
    editorT. Davis
    kindoptimization problem
    2D/3D problem?no

    Ordering statistics:AMD METIS DMPERM+
    nnz(chol(P*(A+A'+s*I)*P'))2,371,331 2,863,298 2,800,720
    Cholesky flop count1.2e+008 2.0e+008 2.0e+008
    nnz(L+U), no partial pivoting4,654,319 5,638,253 5,513,097
    nnz(V) for QR, upper bound nnz(L) for LU320,212,504 - 318,675,915
    nnz(R) for QR, upper bound nnz(U) for LU876,556,249 - 876,377,040

    Maintained by Leslie Foster, last updated 24-Apr-2009.

    Entries 5 through 14 in the table of matrix properties and the singular
    value plot were created using SJsingular code. The other plots
    and statistics are produced using utilities from the SuiteSparse package.
    Matrix color plot pictures by cspy, a MATLAB function in the CSparse package.