• 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/bcspwr04
  • Description: SYMMETRIC STRUCTURE EQUIVALENCED REPRESENTATION OF U.S. POWER NETWORK
  • download as a MATLAB mat-file, file size: 5 KB. Use SJget(60) or SJget('HB/bcspwr04') in MATLAB.
  • download in Matrix Market format, file size: 3 KB.
  • download in Rutherford/Boeing format, file size: 3 KB.

    HB/bcspwr04

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

    HB/bcspwr04

    Matrix properties (click for a legend)  
    number of rows274
    number of columns274
    structural full rank?yes
    structural rank274
    numerical rank 262
    dimension of the numerical null space12
    numerical rank / min(size(A))0.9562
    Euclidean norm of A 10.115
    calculated singular value # 2620.0011149
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    4.8672e-013
    calculated singular value # 2631.1513e-015
    gap in the singular values at the numerical rank:
    singular value # 262 / singular value # 263
    9.6837e+011
    calculated condition number9.7041e+017
    condestInf
    nonzeros1,612
    # 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

    authorB. Dembart, J. Lewis
    editorI. Duff, R. Grimes, J. Lewis
    date1981
    kindpower network problem
    2D/3D problem?no
    SJid60
    UFid16

    Ordering statistics:AMD METIS
    nnz(chol(P*(A+A'+s*I)*P'))1,331 1,427
    Cholesky flop count8.2e+003 9.9e+003
    nnz(L+U), no partial pivoting2,388 2,580
    nnz(V) for QR, upper bound nnz(L) for LU1,835 2,220
    nnz(R) for QR, upper bound nnz(U) for LU3,790 4,516

    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.