function X=nthret(I,F,varargin)
% nthret - Evaluate function and return Nth return value.
%
% Usage:
%
% if F is a function that returns M >= I values, then
%    X = nthret(N,F,...)
% evaluates [Z{1:N}]=F(...)
% and returns Z{N}.

Z=cell(I,1);
[Z{:}]=F(varargin{:});
X=Z{I};
