VectorExplicitEuler.groovy

package eu.mihosoft.vrl.user;
import eu.mihosoft.vrl.user.VectorRhsODEInterface;

/**
 * Explicit Euler Method 
 */
@ComponentInfo(name="VectorExplicitEuler", category="ODE")
public class VectorExplicitEuler implements java.io.Serializable {
  private static final long serialVersionUID=1L;

  private transient boolean stop

  public void stop() {
    this.stop = true
  }

  @OutputInfo(name="VectorTrajectory")
  public VectorTrajectory run(
                    @ParamInfo(name="f(t,u)")
                    VectorRhsODEInterface f,
                    @ParamGroupInfo(group="Initial Values - u|true|no description")
                    @ParamInfo(name="u0", style="array", options="")
                    double[] u0,
                    @ParamGroupInfo(group="Interval - t|true|no description")
                    @ParamInfo(name="t0", options="value=0.0D")
                    double t0,
                    @ParamGroupInfo(group="Interval - t")
                    @ParamInfo(name="tn", options="value=1.0D")
                    double tn,
                    @ParamInfo(name="h", options="value=1e-2D")
                    double h,
                    @ParamInfo(name="Label", options="value=\"expl. Euler\"")
                    String label){

     u0 = u0.clone()

     // create new (and empty) trajectory
     VectorTrajectory trajectory = new VectorTrajectory();

     // check if time interval is correctly chosen by user
     if(t0 > tn){
       throw new IllegalArgumentException("t0 > tn is not allowed.");
       // throw new RuntimeException("Error Text");
     }
 
     // add first (i.e. start) timepoint to the trajectory
     trajectory.add(t0, u0);

     // notation: 
     // we refer to t0, u0 as the current time point and its solution (that is already known)
     // we refer to t, u   as the next time point an its solution (that must be computed)    

      stop = false

     // loop time steps until the current time point is the final time point
     while( t0 < tn) {

       if(stop) {
        break;
       }
        // TODO
     }
    
     return trajectory;
  }

}