Example usage for org.apache.commons.math3.complex Quaternion getScalarPart

Introduction

In this page you can find the example usage for org.apache.commons.math3.complex Quaternion getScalarPart.

Prototype

public double getScalarPart() 

Source Link

Document

Gets the scalar part of the quaternion.

Usage

From source file:etomica.virial.MCMoveClusterRingRegrowOrientation.java

public void rotateVectorV(double angle, IVector axis, IVectorMutable v) {
    double q0 = Math.cos(angle / 2.0);
    double sth2 = Math.sin(angle / 2.0);
    IVectorMutable a1 = space.makeVector();
    a1.E(axis);//  w  w  w .  j a  v a 2s  .com
    a1.TE(sth2);
    double q1 = a1.getX(0);
    double q2 = a1.getX(1);
    double q3 = a1.getX(2);
    Quaternion q = new Quaternion(q0, q1, q2, q3);
    Quaternion vec = new Quaternion(0, v.getX(0), v.getX(1), v.getX(2));
    Quaternion w = q.multiply(vec).multiply(q.getConjugate());
    if (Math.abs(w.getScalarPart()) > 1E-10)
        throw new RuntimeException("Quaternion product is not a vector!");
    v.E(w.getVectorPart());
}

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