Matrix: Um/2cubes_sphere

Description: FEM, electromagnetics, 2 cubes in a sphere. Evan Um, Geophysics, Stanford

Um/2cubes_sphere graph
(undirected graph drawing)


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  • download as a MATLAB mat-file, file size: 13 MB. Use UFget(1919) or UFget('Um/2cubes_sphere') in MATLAB.
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    Matrix properties
    number of rows101,492
    number of columns101,492
    structural full rank?yes
    structural rank101,492
    # of blocks from dmperm1
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    Cholesky candidate?yes
    positive definite?yes

    authorE. Um
    editorT. Davis
    kindelectromagnetics problem
    2D/3D problem?yes

    Additional fieldssize and type
    bfull 101492-by-1


    A matrix from Evan Um, Geophysics, Stanford.  Studying finite-element  
    time domain solvers for electromagnetic diffusion equations. The 3-D   
    computational domain consists of 88,213 tetrahedral elements.  The     
    computational domain consists of the two parts.  First, there are two  
    300m x 300m x 150m boxes where a fine mesh is used.  Second, the two   
    boxes are enclosed by a large sphere whose radius is 10 km.  An element
    growth factor is used to increase the mesh size gradually inside the   
    sphere.  This is because absorbing boundary conditions are not very    
    good choices for these problems.  The finite element technique is      
    edge-based rather than node-based.  Therefore, the unknowns are        
    amplitudes of electromagnetic fields on an edge of each element.       

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD88,679,332
    Cholesky flop count3.0e+11
    nnz(L+U), no partial pivoting, with AMD177,257,172
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD209,702,037
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD394,050,005

    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.