public NDArray <T> arange(int start, int stop, int step = 1) { if (start > stop) { throw new Exception("parameters invalid"); } switch (typeof(T).Name) { case "Int32": { var n = new NDArray <int>(); n.arange(stop, start, step); return(n as NDArray <T>); } case "Double": { var n = new NDArray <double>(); n.arange(stop, start, step); return(n as NDArray <T>); } default: throw new NotImplementedException(); } }