Majority Filter algorithm when majority of neighbors have NoData

Discussion created by mdaum14 on Apr 30, 2014
Latest reply on May 1, 2014 by mdaum14
I'm trying to understand how the Majority Filter tool works around the edges and in sparse areas, where most of the neighboring cells have NoData value.  I have my filter set to use EIGHT neighbors, with replacement on MAJORITY.  If only 1 of the 8 neighbors has a value, the cell is replaced by NoData.  However, if 2 or 3 of the cell's neighbors have values (and all the same value), and the remaining 5 or 6 neighbors have NoData, then the cell seems to be replaced by the existing neighbor values.  There is obviously some nuance in the algorithm that's not clear to me from the online documentation.  Can someone explain this?

FWIW, I encountered this going thru the site selection tutorial that comes with the Spatial Analyst package.