No, the * in the function parameter is wrong. In C, adding a '*' means getting the content of the series. But the function does not want the content, it wants the series as a parameter. The '*' is not a part of the name.

The '500' in the LowPass line is the period for the lowpass filter.

- We've gotten many similar questions, the '*' before the name seems to be a source of confusion for people learning C. Because knowing pointers is not really required for strategy development, in the next tutorial version we'll avoid it altogether and will define series without the '*'. So if the '*' confuses you, just forget it and switch to the new online tutorial:

http://zorro-trader.com/manual/en/tutorial_trade.htm