Matrix properties
number of rows	101,492
number of columns	101,492
nonzeros	1,647,264
structural full rank?	yes
structural rank	101,492
# of blocks from dmperm	1
# strongly connected comp.	1
explicit zero entries	0
nonzero pattern symmetry	symmetric
numeric value symmetry	symmetric
type	real
structure	symmetric
Cholesky candidate?	yes
positive definite?	yes

author	E. Um
editor	T. Davis
date	2008
kind	electromagnetics problem
2D/3D problem?	yes

Additional fields	size and type
b	full 101492-by-1

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.       

Ordering statistics:	result
nnz(chol(P*(A+A'+s*I)*P')) with AMD	88,679,332
Cholesky flop count	3.0e+11
nnz(L+U), no partial pivoting, with AMD	177,257,172
nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD	209,702,037
nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD	394,050,005

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.