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

  • Matrix: JGD_Franz/Franz3
  • Description: Cohomology of various rings, from Matthias Franz, Univ. Konstanz, Germany
  • download as a MATLAB mat-file, file size: 28 KB. Use SJget(633) or SJget('JGD_Franz/Franz3') in MATLAB.
  • download in Matrix Market format, file size: 40 KB.
  • download in Rutherford/Boeing format, file size: 28 KB.


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


    Matrix properties (click for a legend)  
    number of rows1,280
    number of columns2,800
    structural full rank?yes
    structural rank1,280
    numerical rank 1,025
    dimension of the numerical null space1,775
    numerical rank / min(size(A))0.80078
    Euclidean norm of A 6.3246
    calculated singular value # 10251.1777
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    calculated singular value # 10266.3003e-015
    gap in the singular values at the numerical rank:
    singular value # 1025 / singular value # 1026
    calculated condition number2.4107e+017
    # 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

    authorM. Franz
    editorJ.-G. Dumas
    kindcombinatorial problem
    2D/3D problem?no


    Cohomology of various rings, from Matthias Franz, Univ. Konstanz, Germany
    From Jean-Guillaume Dumas' Sparse Integer Matrix Collection,             
    Filename in JGD collection: Franz/1280x2800                              

    Ordering statistics:AMD METIS
    nnz(V) for QR, upper bound nnz(L) for LU1,490,496 1,387,434
    nnz(R) for QR, upper bound nnz(U) for LU443,191 421,449

    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.