hypsom_ut

 PURPOSE: colfilt function to calculate the mean of the highest 30%
 altitude values. Returns NaN if more than 50% of input cells are NaN,
 else removes NaN cells for calculation.

 See also: colfilt()

 Felix Hebeler, Geography Dept., University Zurich, Jan 2007.

0001 function [r] = hypsom_ut(X)
0002 % PURPOSE: colfilt function to calculate the mean of the highest 30%
0003 % altitude values. Returns NaN if more than 50% of input cells are NaN,
0004 % else removes NaN cells for calculation.
0005 %
0006 % See also: colfilt()
0007 %
0008 % Felix Hebeler, Geography Dept., University Zurich, Jan 2007.
0009 
0010 %r=X(ceil(size(X,1)/2),:);
0011 n=sum(isnan(X(:)));
0012 if n>0
0013     if n>=numel(X)/2
0014         r=nan;
0015         return
0016     else
0017         X(isnan(X))=[];
0018     end
0019 end
0020 r=quantile(X(:),0.85);
0021