using variables form a prior bar's calulations

[roland_nt]

I am building a Fourier transform indicator which calculates 50 values for a certain parameter, let's say the parameter is named "Real".
So there is a Real[0] through Real[49] for the current bar (i.e. bar[0]).
The calculation needs to reference the prior bar's 50 values for Real (i.e. Bar[1]) as well as the 50 values of Real for the bar before that (bar[2]).

What NinjaTrader data type would I use to declare Real so that the prior bar's calculation values are available?

The NinjaTrader DataSeries type
only stores one value for each bar, not 50.

Real is not a straight 2 dimensional array, since that would reset every thing to 0 each time the indicator executes.

I really need sonething like this
(conceptual example only, might not be correct C#)
Real[3] = new DataSeries (this);
to be referenced in code possibly like this
N = Real[0][25] + Real[1][25] + Real[2][25];
and possibly loaded something like this
Real.Set(A*N-1)[0][25];

I do not need to keep any more than 3 bars back worth of 50 values for each bar.

If this is the wrong forum for this question, please direct me to the proper forum.