• SJSU Singular Matrix Database
  • Matrix group: JGD_Groebner
  • Click here for a description of the JGD_Groebner group.
  • Click here for a list of all matrices
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  • Matrix: JGD_Groebner/f855_mat9_I
  • Description: Groebner basis from Jean-Charles Fauge`res
  • download as a MATLAB mat-file, file size: 643 KB. Use SJget(649) or SJget('JGD_Groebner/f855_mat9_I') in MATLAB.
  • download in Matrix Market format, file size: 863 KB.
  • download in Rutherford/Boeing format, file size: 515 KB.


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


    Matrix properties (click for a legend)  
    number of rows2,456
    number of columns2,511
    structural full rank?yes
    structural rank2,456
    numerical rank 2,228
    dimension of the numerical null space283
    numerical rank / min(size(A))0.90717
    Euclidean norm of A 5.899e+006
    calculated singular value # 22282.3591e-006
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    calculated singular value # 22292.3233e-006
    gap in the singular values at the numerical rank:
    singular value # 2228 / singular value # 2229
    calculated condition number1.4892e+018
    # of blocks from dmperm1
    # strongly connected comp.1
    entries not in dmperm blocks0
    explicit zero entries0
    nonzero pattern symmetry 0%
    numeric value symmetry 0%
    Cholesky candidate?no
    positive definite?no

    authorJ.-C. Faugeres
    editorJ.-G. Dumas
    kindcombinatorial problem
    2D/3D problem?no


    Gro"bner basis from Jean-Charles Fauge`res,                 
    From Jean-Guillaume Dumas' Sparse Integer Matrix Collection,
    Filename in JGD collection: Grobner/f855_mat9.I             

    Ordering statistics:AMD METIS
    nnz(V) for QR, upper bound nnz(L) for LU1,700,978 1,710,514
    nnz(R) for QR, upper bound nnz(U) for LU2,579,991 2,896,454

    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.