Java Array Normalize normal0(double[] p1, double[] p2, double[] p3)

Description

computes the unit normal vector on the plane p1p2p3 as normalize(p2p1 x p2p3)

License

Open Source License

Declaration

public static double[] normal0(double[] p1, double[] p2, double[] p3) 

Method Source Code

//package com.java2s;
//License from project: Open Source License 

public class Main {
    /**//from  w  w w . j  a  v a 2  s  . com
    computes the unit normal vector on the plane p1p2p3 as
    normalize(p2p1 x p2p3)
     */
    public static double[] normal0(double[] p1, double[] p2, double[] p3) {
        double[] v21 = subtract(p1, p2);
        double[] v23 = subtract(p3, p2);
        return (normalize(crossprod(v21, v23)));
    }

    /** subtracts two vectors v1-v2
     */
    public static double[] subtract(double[] v1, double[] v2) {
        double[] v = new double[3];
        v[0] = v1[0] - v2[0];
        v[1] = v1[1] - v2[1];
        v[2] = v1[2] - v2[2];
        return (v);
    }

    /** returns vector v normalized */
    public static double[] normalize(double[] v) {
        double[] v0 = new double[3];
        double n = norm(v);
        v0[0] = v[0] / n;
        v0[1] = v[1] / n;
        v0[2] = v[2] / n;
        return (v0);
    }

    /** general cross product function for vectors in three dimensions
     */
    public static double[] crossprod(double[] v1, double[] v2) {
        double[] v = new double[3];
        v[0] = v1[1] * v2[2] - v1[2] * v2[1];
        v[1] = v1[2] * v2[0] - v1[0] * v2[2];
        v[2] = v1[0] * v2[1] - v1[1] * v2[0];
        return (v);
    }

    /** returns the norm of the vector*/
    public static double norm(double[] v) {
        return (Math.sqrt(dotprod(v, v)));
    }

    /** computes the dot product v1*v2.*/
    public static double dotprod(double[] v1, double[] v2) {
        return (v1[0] * v2[0] + v1[1] * v2[1] + v1[2] * v2[2]);
    }
}

Related

1. norm2(double[] vector)
2. norm2(double[] x)
3. norm2DoubleArray(double[] v)
4. norm_variance(double[] array)
5. norm_vec(double[] vec)
6. normalCentralMoment(boolean[][] img, int p, int q)
7. normalDist(double[] features, double[] avg, double[][] cov)
8. normalForm(int[] a)
9. normalHashCode(char[] val)