indToBernstienInd.m

function result = indToBernstienInd(d, k)
% Convert ordinary order to lexicographical order.
% Input:
%     @d: integer, dimension of spline space.
%     @k: integer, position on ordinary sequence order
% Output:
%     @result: vector[3], position of k on exicography order
    
    result = zeros(1,3);
    delt = @(k) ceil((-3 + sqrt(9+8*(k-1)))/2);
    
    result(1) = d - delt(k);
    result(3) = k - ((d-result(1)+1)*(d-result(1)))/2 - 1;
    result(2) = d - result(1) - result(3);
end