Tbsc(alpha,p);

function res = Tbsc(alpha,p);

% constant for Tukey Biweight S 

talpha = sqrt(chi2inv(1-alpha,p));
maxit = 1000; 
eps = 10^(-8);
diff = 10^6;
ctest = talpha;
iter = 1;
while ((diff>eps) & iter<maxit)
    cold = ctest;
    ctest = Tbsb(cold,p)/alpha;
    diff = abs(cold-ctest);
    iter = iter+1;
end
res = (ctest);

%-----------------------------------------------------------------------