Matrix A defined on nodes , aggregate size bounds , , aggregation radius r and number of smoothing steps
Output
Set of ( non-overlapping) aggregates
Scale the matrix
Filter out weak connections from matrix for which ;
Initialise ; ;
repeat ... until
; choose a seednode from (or randomly from set if )
Set layer ; and
for
Set layer
If , add to all that are connected through to at least 2 nodes in , set and set .
Find (i.e. the largest layer) and add to all of shortest path length from
set
Merge any aggregate that is too small (i.e. ) with a connected neighbouring aggregate (subject to the requirement ; it may be necessary to split up to achieve this) and shrink accordingly.
The smoothing is then done to get restriction matrix and coarse problem (see Smoothed Coarse Spaces).
Generated on Thu Mar 17 2011 15:10:02 for DOUG by
1.7.3-20110217