N: (int, optional) Number of columns in the output. If N is not specified, a square array is returned (N=len(x)).
increasing: (bool, optional) Order of the powers of the columns. If TRUE, the powers increase from left to right, if FALSE (the default) they are reversed.
vander(x, N=None, increasing=FALSE) -> Tensor
Generates a Vandermonde matrix.
The columns of the output matrix are elementwise powers of the input vector x(N−1),x(N−2),...,x0. If increasing is TRUE, the order of the columns is reversed x0,x1,...,x(N−1). Such a matrix with a geometric progression in each row is named for Alexandre-Theophile Vandermonde.