Matrix: Boeing/nasa1824

Description: STRUCTURE FROM NASA LANGLEY, 1824 DEGREES OF FREEDOM

Boeing/nasa1824 graph
(undirected graph drawing)


Boeing/nasa1824

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  • Matrix group: Boeing
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  • download as a MATLAB mat-file, file size: 197 KB. Use UFget(363) or UFget('Boeing/nasa1824') in MATLAB.
  • download in Matrix Market format, file size: 159 KB.
  • download in Rutherford/Boeing format, file size: 128 KB.

    Matrix properties
    number of rows1,824
    number of columns1,824
    nonzeros39,208
    structural full rank?yes
    structural rank1,824
    # of blocks from dmperm1
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typereal
    structuresymmetric
    Cholesky candidate?yes
    positive definite?no

    authorR. Grimes
    editorT. Davis
    date1995
    kindduplicate structural problem
    2D/3D problem?yes

    Additional fieldssize and type
    bfull 1824-by-1

    Notes:

    Let A1=Nasa/nasa1824 and A2=Boeing/nasa1824.  A1 and A2 have the same 
    nonzero pattern.  A1 and A2 differ in value in only 386 entries out of
    39208, and only in 21 columns of the lower triangular part;           
    tril(A(196:321,196:216)) and the same rows of the upper triangular    
    part.  The magnitudes of the entries in A2 in this region of the      
    matrix are all tiny, and have only 9 digits if printed in base-10     
    (unlike the other entries, which have full precision).  I suspect A2  
    (Boeing/nasa1824) is a corrupted version of A1 (Nasa/nasa1824).       
    

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD69,309
    Cholesky flop count4.6e+06
    nnz(L+U), no partial pivoting, with AMD136,794
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD157,808
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD289,058

    SVD-based statistics:
    norm(A)2.12172e+07
    min(svd(A))3.60113
    cond(A)5.8918e+06
    rank(A)1,824
    sprank(A)-rank(A)0
    null space dimension0
    full numerical rank?yes

    singular values (MAT file):click here
    SVD method used:s = svd (full (A)) ;
    status:ok

    Boeing/nasa1824 svd

    For a description of the statistics displayed above, click here.

    Maintained by Tim Davis, last updated 12-Mar-2014.
    Matrix pictures by cspy, a MATLAB function in the CSparse package.
    Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.