%-------------------------------------------------------------------------------
% UF Sparse Matrix Collection, Tim Davis
% http://www.cise.ufl.edu/research/sparse/matrices/Um/2cubes_sphere
% name: Um/2cubes_sphere
% [FEM, electromagnetics, 2 cubes in a sphere. Evan Um, Geophysics, Stanford]
% id: 1919
% date: 2008
% author: E. Um
% ed: T. Davis
% fields: name title A b id date author ed kind notes
% kind: electromagnetics problem
%-------------------------------------------------------------------------------
% notes:
% 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.       
%-------------------------------------------------------------------------------
