Vandermonde

vander(input: any[] | Mat | Tensor, dim : Number) : Mat

param input a JS array, matrix or tensor (will be flattened to a 1-d array)

param dim a number which should be >= 0, the dimension of the vandermonde matrix

returns - Mat - a vander matrix

A vandermonde matrix is defined by a set of scalars, which in this case, come from a 1d array (flattened if 2d or higher), and you can limit it by dim.

A vandermonde matrix is shown as follows

$$\begin{bmatrix} 1 & x_1 & x_1^2 & ... & x_1^{dim} \\ . & . & . & . & . \\ . & . & . & . & .\\ . & . & . & . & .\\ 1 & x_n & x_n^2 & ... & x_n^{dim} \end{bmatrix}$$