// test_rderiv.java

class test_rderiv
{
  test_rderiv()
  {
    int np = 7;
    double cx[] = new double[np];
    double cxx[] = new double[np];
    double x[] = new double[np];
    double y[] = new double[np];
    double yp[] = new double[np];
    double ypp[] = new double[np];
    int order = 1;
    double hx = 0.1;
    double deriv = 0.0;
    double maxerr = 0.0;
    
    System.out.println("test_rderiv.java running");
    System.out.println("hx="+hx);
    for(int i=0; i<np; i++)
    {
      x[i] = 1.0+(double)i*hx;
      y[i] = x[i]*x[i]*x[i]+2.0*x[i]*x[i];
      yp[i] = 3.0*x[i]*x[i]+4.0*x[i];
      ypp[i] = 6.0*x[i]+4.0;      
      System.out.println("x["+i+"]="+x[i]+"  y[i]="+y[i]+"  yp[i]="+yp[i]);
    } // end i
    order = 1;
    System.out.println("order="+order);
    for(int i=0; i<np; i++)
    {
      new rderiv(order, np, i, hx, cx);
      System.out.println("rderiv order="+order+"  points="+np+"  point="+i);
      deriv = 0.0;
      for(int j=0; j<np; j++)
      {
        System.out.println("cx["+j+"]="+cx[j]);
	deriv = deriv + cx[j]*y[j];  
      }
      System.out.println("deriv="+deriv+"  should be="+yp[i]);
      System.out.println(" ");
      maxerr = Math.max(maxerr, Math.abs(deriv-yp[i]));
    }
    System.out.println(" ");

    order = 2;
    for(int i=0; i<np; i++)
    {
      new rderiv(order, np, i, hx, cxx);
      System.out.println("rderiv order="+order+"  points="+np+"  point="+i);
      deriv = 0.0;
      for(int j=0; j<np; j++)
      {
        System.out.println("cxx["+j+"]="+cxx[j]);
        deriv = deriv + cxx[j]*y[j];
      }
      System.out.println("deriv="+deriv+"  should be="+ypp[i]);
      System.out.println(" ");
      maxerr = Math.max(maxerr, Math.abs(deriv-ypp[i]));
    }
    System.out.println(" ");
    System.out.println("maxerr="+maxerr);
    
    System.out.println("test_rderiv finished");
  } // end test_rderiv

  public static void main (String[] args)
  {
    new test_rderiv();
  }
} // end class test_rderiv