wolffd@0: function p = mkPolyFvec(x)
wolffd@0: % MKPOLYFVEC Make feature vector by constructing 2nd order polynomial from input data
wolffd@0: % function p = mkPolyFvec(x)
wolffd@0: %
wolffd@0: % x(:,i) for example i
wolffd@0: % p(:,i) = [x(1,i) x(2,i) x(3,i) x(1,i)^2 x(2,i)^2 x(3,i)^2 ..
wolffd@0: %           x(1,i)*x(2,i) x(1,i)*x(3,i) x(2,i)*x(3,i)]'
wolffd@0: %
wolffd@0: % Example
wolffd@0: % x = [4 5 6]'
wolffd@0: % p = [4 5 6  16 25 36  20 24 30]'
wolffd@0: 
wolffd@0: fvec = x;
wolffd@0: fvecSq = x.*x;
wolffd@0: [D N] = size(x);
wolffd@0: fvecCross = zeros(D*(D-1)/2, N);
wolffd@0: i = 1;
wolffd@0: for d=1:D
wolffd@0:   for d2=d+1:D
wolffd@0:     fvecCross(i,:) = x(d,:) .* x(d2,:);
wolffd@0:     i = i + 1;
wolffd@0:   end
wolffd@0: end
wolffd@0: p = [fvec; fvecSq; fvecCross];