How can I compute coefficient of determination(R^2) of robust regresstion?

    x=[1,2,3,4,5,6,7,8,9,10];
    y=[1.1,2.1,13.1,4.3,5.4,5.8,6.9,7.8,16,10.1];
    [b,stat]=robustfit(x,y,'bisquare');
    sse=stat.dfe*stat.robust_s^2;
    phat = b(1) + b(2)*x;
    ssr = norm(phat-mean(y))^2; % ssr = norm(phat-mean(phat))^2; are also tested
    R^2=1-sse/ssr

but sse and ssr are not same to the results of cftool ,nor the R^2.

thak you for your help