B=nansubsref(A,I)

function B=nansubsref(A,I)
%NANSUBSREF Subscripted reference, ignoring NaNs.
%   B=NANSUBSREF(A,I) is an array formed from the elements of A specified
%   by the subscript vector I.  The resulting array is the same size as I.

B=nan(size(I));
InnnanI=find(~isnan(I));
B(InnnanI)=A(I(InnnanI));