Examples of ConjugateGradients

   */
  public void testConjugateGradients1() {
    
    double epsilon = 1e-7;
    
    Solver s = new ConjugateGradients();
    
    Body b1 = new Body("default");
    Body b2 = new Body("default");
    
    Solver.NCPConstraint c1 = new NCPConstraint();
    Vector3 va =new Vector3(1,0,0);
    Vector3 vb =new Vector3(-1,0,0);
    Vector3 z = new Vector3(0,0,0);
    c1.assign(b1,b2,
        va,z,vb,z,
        va,z,vb,z,
        -Double.POSITIVE_INFINITY,Double.POSITIVE_INFINITY,null,1, 0);
    
    //This is the system
    //
    // [ 1 0 0  0 0 0  -1 0 0  0 0 0] [1 0 0  0 0 0  -1 0 0  0 0 0 ]^T x + 1= 0  =>
    // 2 x + 1 = 0  
    //
    // with the solution x = -1/2 
    
    //list of bodies and constraints
    List<Body> bodies = new ArrayList<Body>();
    List<NCPConstraint> constraints = new ArrayList<NCPConstraint>();
    bodies.add(b1); bodies.add(b2); constraints.add(c1);


    //run the solver
    s.solve(constraints, bodies, 0.0);
    
    System.out.println("cg test="+c1.lambda);
    
    //expect solution 1/2
    assertTrue( Math.abs(-0.5 - c1.lambda) < epsilon );

   */
  public void testConjugateGradients2() {
    
    double epsilon = 1e-7;
    
    Solver s = new ConjugateGradients();
    Body b1 = new Body("default");
    Body b2 = new Body("default");
    
    Solver.NCPConstraint c1 = new NCPConstraint();
    Solver.NCPConstraint c2 = new NCPConstraint();


    Vector3 va =new Vector3(1,0,0);
    Vector3 vb =new Vector3(-1,0,0);
    Vector3 z = new Vector3(0,0,0);
    c1.assign(b1,b2,
        va,z,vb,z,
        va,z,vb,z,
        0,0,null,1, 0);
    c2.assign(b1,b2,
        va,z,vb,z,
        va,z,vb,z,
        0,0,null,1, 0);


    
    //This is the system
    //
    // [ 1 0 0  0 0 0  -1 0 0  0 0 0] [1 0 0  0 0 0  -1 0 0  0 0 0 ]^T x + 1 = 0  
    // [ 1 0 0  0 0 0  -1 0 0  0 0 0] [1 0 0  0 0 0  -1 0 0  0 0 0 ]           =>
    //
    // 2  2 x1 + 1 = 0  
    // 2  2 x2 + 1 = 0
    //
    // with a least squares solution solution x1 = -1/4 and x2 = -1/4 
    
    //list of bodies and constraints
    List<Body> bodies = new ArrayList<Body>();
    List<NCPConstraint> constraints = new ArrayList<NCPConstraint>();
    bodies.add(b1); bodies.add(b2); constraints.add(c1); constraints.add(c2);


    //run the solver
    s.solve(constraints, bodies, 0.0);
    
    System.out.println("("+c1.lambda+","+c2.lambda+")");
    
    //expect solution (1/4,1/4)
    assertTrue( Math.abs(-0.25 - c1.lambda) < epsilon );

Examples of ConjugateGradients

Examples of jinngine.physics.solver.ConjugateGradients

Examples of jinngine.physics.solver.ConjugateGradients