function output=leastnonzero(array)
% This function finds the least non-zero value given an array.
% For example,
%   x=[ 3 2 1; -1 3 -5];
%   y=leastnonzero(x)
%
%   output: y=1
% Author: David Li
% Date: April 28, 2005

[n m]=size(array);
input=reshape(array,n*m,1);
input=sort(input);

while(min(input)<=0)
    if (max(input)<=0)
        break
    end  
    input=input(2:end);
end

output=min(input);