ndarray-vandermonde

Construct an ndarray vandermonde matrix

Introduction

A Vandermonde matrix is a matrix with format:

It's useful for least squares fits, among other things, in which you want a set of basis vectors that are successive powers of a variable evaluated at specific points. It's usually just plug and chug into QR or SVD in order to solve the least squares problem.

Usage

vander( x [, N] [, reversed] )

x is a vector of numbers, N is the width of the resulting matrix (i.e. the highest power + 1), and reversed is a flag that will reverse the columns of the resulting matrix so that higher powers are on the left.

For example,

var vander = require('ndarray-vandermonde'),
    ndarray = require('ndarray');

var x = ndarray(Float64Array([1,2,3,4]));

var y = vander(x);

Credits

(c) 2015 Ricky Reusser. MIT License