code: public static cuComplex cuCmplx (float r, float i)
      {
          cuComplex res = new cuComplex();
          res.x = r;
          res.y = i;
          return res;
      }
docs: Creates a new complex number consisting of the given real and
  imaginary part.
  
  @param r The real part of the complex number
  @param i The imaginary part of the complex number
  @return A complex number with the given real and imaginary part