• 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/can_256
  • Description: SYMMETRIC PATTERN FROM CANNES,LUCIEN MARRO,JUNE 1981.
  • download as a MATLAB mat-file, file size: 6 KB. Use SJget(75) or SJget('HB/can_256') in MATLAB.
  • download in Matrix Market format, file size: 4 KB.
  • download in Rutherford/Boeing format, file size: 3 KB.

    HB/can_256

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

    HB/can_256

    Matrix properties (click for a legend)  
    number of rows256
    number of columns256
    structural full rank?yes
    structural rank256
    numerical rank 250
    dimension of the numerical null space6
    numerical rank / min(size(A))0.97656
    Euclidean norm of A 16.037
    calculated singular value # 2500.0012512
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    9.0949e-013
    calculated singular value # 2513.2459e-015
    gap in the singular values at the numerical rank:
    singular value # 250 / singular value # 251
    3.8548e+011
    calculated condition number1.3578e+017
    condestInf
    nonzeros2,916
    # of blocks from dmperm1
    # strongly connected comp.1
    entries not in dmperm blocks0
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typebinary
    structuresymmetric
    Cholesky candidate?yes
    positive definite?no

    authorL. Marro
    editorI. Duff, R. Grimes, J. Lewis
    date1981
    kindstructural problem
    2D/3D problem?yes
    SJid75
    UFid98

    Ordering statistics:AMD METIS
    nnz(chol(P*(A+A'+s*I)*P'))3,512 3,745
    Cholesky flop count6.2e+004 7.2e+004
    nnz(L+U), no partial pivoting6,768 7,234
    nnz(V) for QR, upper bound nnz(L) for LU7,799 8,408
    nnz(R) for QR, upper bound nnz(U) for LU17,106 17,342

    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.