Here you can find the source of minus(double[] a)
static double[] minus(double[] a)
//package com.java2s; //License from project: Open Source License public class Main { static double[] minus(double[] a) { final double[] r = new double[a.length]; for (int i = 0; i < a.length; ++i) { r[i] = -a[i];//from w ww . ja v a2s . c om } return r; } }