Three ways of generating a Vandermonde matrix

vandermonde.sci

// Three ways of generating a Vandermonde matrix: 

function y = vandermonde1(x)
  n = length(x)
  for i = 1:n
    y(:, i) = x^(i-1)
  end
endfunction

function y = vandermonde2(a)
  n = length(a)
  y=[a*ones(1,4)].^[[0:n-1]'*ones(1,4)]'
endfunction

function y = vandermonde3(a)
  n = length(a)
  y = kron(a, ones(1, n)).^kron([0:n-1]', ones(1, n))'
endfunction