public double[][] eval(double[][] dest, NslDouble2 a, NslDouble2 b) {
   return eval(dest, a.getdouble2(), b.getdouble2());
 }
 public double[][] eval(double a, NslDouble2 b) {
   return eval(a, b.getdouble2());
 }
 public double[][] eval(NslDouble2 a, NslDouble2 b) {
   return eval(a.getdouble2(), b.getdouble2());
 }
 public double[][] eval(NslDouble2 a, double b) {
   return eval(a.getdouble2(), b);
 }