return np.array(x), np.array(y), np.array(u), np.array(r).reshape(-1, 1), np.array(d).reshape(-1, 1)

This code converts the input variables x, y, u, r, and d into numpy arrays and returns them as a tuple.

- np.array(x) converts x into a numpy array.
- Similarly, np.array(y), np.array(u), np.array(r).reshape(-1, 1), and np.array(d).reshape(-1, 1) convert y, u, r, and d into numpy arrays.
- The reshape method is used to convert r and d into 2D arrays with a single column (-1 is used to automatically determine the number of rows based on the length of the array).
- Finally, all the numpy arrays are combined into a tuple and returned.