--- a
+++ b/Semantic Features/GetLargestMatrix.m
@@ -0,0 +1,19 @@
+function [ LargestMatrix ] = GetLargestMatrix( InputMatrix, largestIDs, instanceIDs )
+%GetLargestMatrix 
+%   Kind of a strange function. You feed this the IDs of the rows that you
+%   want to use as 'largest area border of that slice' and it will get
+%   those rows for you in order. Testing with another function confirmed
+%   this is the same order as the Y matrix we're using, so no need to try
+%   and reorder the data. 
+
+%get the rows of the instance IDs that match the instance IDs to generate
+%Patrick's segmentations (same order)
+for i = 1:length(largestIDs)
+   largestRows(i) = find(largestIDs(i) == instanceIDs); 
+end
+
+largestRows = largestRows';
+LargestMatrix = InputMatrix(largestRows,:);
+
+
+end
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