scijs/ndarray-vandermonde

Name: ndarray-vandermonde

Owner: scijs

Description: Construct Vandermonde matrices with ndarrays

Created: 2015-05-04 11:36:11.0

Updated: 2015-05-10 03:46:48.0

Pushed: 2015-05-12 12:30:50.0

Homepage: null

Size: 152

Language: JavaScript

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README

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; the resulting matrix is square by default), and reversed is a flag that will reverse the columns of the resulting matrix so that higher powers are on the left.

For example,

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

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

y = vander(x);

Credits

(c) 2015 Ricky Reusser. MIT License