What's the best way to retrieve the previous day's closing price and the current day's opening price while using an intraday chart? Also, how does displaying pre- and post-market data affect those results?

I found this listed under the TS Development Environment help file, but when running this indicator in RadarScreen, it only displays a "-1".

 

Code

Example Assigns the Close of the previous day on an intraday chart to Value1, then plots Value1: Value1 = CloseD(1); Plot1(Value1, "PrevClose");

I know this is really old but I was looking for info on this function and found that if it returns -1 you likely don't have enough data or referencing more than 50 periods back.