A simple Moving Average not simple?

[joemeyer]

If
return sma(14,close());

gives me the 14 period simple moving average, why does

return sma(14,(close(-1));

not give me a displaced 14 period moving average,
or

return sma(14, open() - close())

not give me the 14 period average of the difference?

I am missing something?
Thank you for helping me with what should be very simple stuff!
Joe

[ACM]

joemeyer
You are not getting an average because close(-1) and open()-close() are values and not series which are instead required as a source by a builtin study.
In the first case if you want to displace the average you could use either of the following
sma(14, close(),-1)
or
offsetSeries(sma(14,close()),1)
In the second case you would need to compute your open()-close() equation in a separate function and then call that function using efsInternal() to create the series which you can pass to the sma() function.
For more information and examples on the use of efsInternal() see also this thread
Alex