PseudoVandermonde matrix of given degrees.
Returns the pseudoVandermonde matrix of degrees deg and sample points (x, y). The pseudoVandermonde matrix is defined by
where 0 <= i <= deg[0] and 0 <= j <= deg[1]. The leading indices of V index the points (x, y) and the last index encodes the powers of x and y.
If V = polyvander2d(x, y, [xdeg, ydeg]), then the columns of V correspond to the elements of a 2D coefficient array c of shape (xdeg + 1, ydeg + 1) in the order
and np.dot(V, c.flat) and polyval2d(x, y, c) will be the same up to roundoff. This equivalence is useful both for least squares fitting and for the evaluation of a large number of 2D polynomials of the same degrees and sample points.
Parameters :  x, y : array_like
deg : list of ints


Returns :  vander2d : ndarray

See also
polyvander, polyvander3d., polyval3d