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


  • Matrix: HB/mahindas
  • Description: UNSYMMETRIC MATRIX MAHINDAS ST ERTAR 24OCT84
  • download as a MATLAB mat-file, file size: 46 KB. Use SJget(296) or SJget('HB/mahindas') in MATLAB.
  • download in Matrix Market format, file size: 44 KB.
  • download in Rutherford/Boeing format, file size: 39 KB.

    HB/mahindas

    Routine svd from Matlab 7.6.0.324 (R2008a) used to calculate the singular values.

    HB/mahindas

    dmperm of HB/mahindas

    Matrix properties (click for a legend)  
    number of rows1,258
    number of columns1,258
    structural full rank?yes
    structural rank1,258
    numerical rank 1,257
    dimension of the numerical null space1
    numerical rank / min(size(A))0.99921
    Euclidean norm of A 2.0451e+007
    calculated singular value # 12570.015039
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    4.6864e-006
    calculated singular value # 12589.8213e-007
    gap in the singular values at the numerical rank:
    singular value # 1257 / singular value # 1258
    15312
    calculated condition number2.0823e+013
    condest1.0343e+013
    nonzeros7,682
    # of blocks from dmperm670
    # strongly connected comp.1
    entries not in dmperm blocks2,269
    explicit zero entries0
    nonzero pattern symmetry 2%
    numeric value symmetry 0%
    typereal
    structureunsymmetric
    Cholesky candidate?no
    positive definite?no

    authorK. Pearson
    editorI. Duff, R. Grimes, J. Lewis
    date1984
    kindeconomic problem
    2D/3D problem?no
    SJid296
    UFid208

    Additional fieldssize and type
    bsparse 1258-by-55

    Ordering statistics:AMD METIS DMPERM+
    nnz(chol(P*(A+A'+s*I)*P'))73,433 79,714 9,978
    Cholesky flop count1.4e+007 1.5e+007 3.2e+005
    nnz(L+U), no partial pivoting145,608 158,170 20,967
    nnz(V) for QR, upper bound nnz(L) for LU20,045 22,162 8,729
    nnz(R) for QR, upper bound nnz(U) for LU50,432 57,973 23,005

    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.