function  A = m_poly(b,X)
% A = m_poly(b,X)
%
% The function returns the polynomial items of X(:). The formula is:
% $$ A_j = x^{j-1}, j=1,...b $$
% The vector b is degree+1 of the polynomial.
%
% Notation:
% X [m x 1] is an input column vector,
% b [1 x 1] is degree+1 of the polynomial.
% A [m x b] is an output matrix of the non-linear  mappings, where each
% column corresponds to an item of the further linear combination. 
%
% Example
% y = m_poly(2,linspace(0,1,10)) % a straight line
%
A = repmat(X(:),[1 b(1)]); % calculate columns of the matrix 
% where each column corresponds to the corresponded degree of the polynomial.
for j = 1:b(1)
    A(:,j)=A(:,j).^(j-1);
end
return