double[]dd_deriv=newdouble[3];// derivatives by dependent dd_pre_lars, dd_last and nd_last (calculated on demand) with sign according to first/second in a pair
double[]dd_deriv=newdouble[3];// derivatives by dependent dd_pre_last (0), dd_last (1) and nd_last (1)
// (calculated on demand) with sign according to first/second in a pair