%
%       Calculate the first difference between
%       points in a series
%       dif=firstdif(series)

% Written by Marinna Martini

function dif=firstdif(series);
m=100;

N=length(series);
for i=1:(N-1),
        dif(i)=abs(series(i)-series(i+1));
        if dif(i) ~= 0,
                if dif(i) < m,
                        m = dif(i);
                end
        end
end

fprintf('Minimum is %f',m)