double biCubicInterpolation(double xCoord,double yCoord){
  try {
    return interpolatingFunction.value(yCoord,xCoord);
  }
 catch (  FunctionEvaluationException e) {
    e.printStackTrace();
  }
  return Double.NaN;
}

double biCubicInterpolation ( double xCoord , double yCoord ) { try { return interpolatingFunction . value ( yCoord , xCoord ) ; } catch ( FunctionEvaluationException e ) { e . printStackTrace ( ) ; } return Double . NaN ; }
interpolates the value at an arbitrary point with bicubic spline interpolation from apache .
