On using MAX

[binwang2]

The help guide on using MAX is the following:
MAX(IDataSeries inputData, int period)[int barsAgo]

My question is on the [int barsAgo] if barsAgo is not 0. I use barsAgo =15 as an example;

MAX(High, 40)[15],
i should get the highest high for the bars between 54 and 15, NOT highest high for most recent 40 bars. In other wors, the period is started at barsAgo and is counted further into the past by 'period' amount.
Is this understaning correct?

[NinjaTrader_Bertrand]

You got it binwang2.