• 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/net25
  • Description: net25 matrix from Alexander Andrianov, SAS Institute Inc.
  • download as a MATLAB mat-file, file size: 392 KB. Use SJget(420) or SJget('Andrianov/net25') in MATLAB.
  • download in Matrix Market format, file size: 426 KB.
  • download in Rutherford/Boeing format, file size: 145 KB.


    Routine svd from Matlab (R2008a) used to calculate the singular values.


    dmperm of Andrianov/net25

    Matrix properties (click for a legend)  
    number of rows9,520
    number of columns9,520
    structural full rank?yes
    structural rank9,520
    numerical rank 9,058
    dimension of the numerical null space462
    numerical rank / min(size(A))0.95147
    Euclidean norm of A 70.426
    calculated singular value # 90580.29266
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    calculated singular value # 90593.0582e-014
    gap in the singular values at the numerical rank:
    singular value # 9058 / singular value # 9059
    calculated condition number1.3041e+019
    # of blocks from dmperm2
    # strongly connected comp.2
    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'))1,500,131 1,625,289 1,500,131
    Cholesky flop count6.5e+008 7.6e+008 6.5e+008
    nnz(L+U), no partial pivoting2,990,742 3,241,058 2,990,742
    nnz(V) for QR, upper bound nnz(L) for LU12,248,007 8,103,288 7,835,422
    nnz(R) for QR, upper bound nnz(U) for LU18,725,968 17,009,581 17,037,382

    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.