public double simulateForward(double value,double time){
  double D=diffusionRateParameter.getParameterValue(0);
  double delta=MathUtils.nextGaussian();
  delta*=Math.sqrt(D * time);
  delta+=getBias() * time;
  return value + delta;
}

public double simulateForward ( double value , double time ) { double D = diffusionRateParameter . getParameterValue ( 0 ) ; double delta = MathUtils . nextGaussian ( ) ; delta *= Math . sqrt ( D * time ) ; delta += getBias ( ) * time ; return value + delta ; }
simulate the diffusion process forward in time .
