average from days available?

[Gordon]

Good Morning Scripters,
Does anyone know if it is possible to have average length conditional on amount of days available. If IPO is 18 days ago, and using an average length of 20, average for the 18? average(volume, "max available up to" 20)

 

[mashume]

Here's a simple moving average and average volume label that will plot n-1 bars back (given n total bars since an IPO)

declare upper;

input max_lookback = 50;

script vma {
input varlen = 10;
input variable = CLOSE;
def vMA = (Fold Index = 0 to VarLen with Data Do
    Data + GetValue(variable, index)) / VarLen;
plot VLMA = vMA;
};

def available_bars = fold i = 0 to max_lookback with s do if !isNan(getValue(close, i)) then s + 1 else s + 0;

addLabel(yes, "  Total Available Bars:  " +  available_bars + "   ", color.gray);

plot ipo_ma = vma(available_bars - 1, CLOSE);
ipo_ma.SetPaintingStrategy(paintingStrategy.LINE_VS_POINTS);

def average_vol_since_ipo = vma(available_bars - 1, VOLUME);

addLabel(yes, "  Average Volume last " + (available_bars - 1) + " bars:  " +  floor(average_vol_since_ipo) + "   ", color.gray);

remember that, since it's plotting a moving average of n-1 bars length, it will start on bar 2 and then each bar will be a slower moving average until the last bar. That is, bar 2 will have a ma length of 1, bar 4 will have a ma length of 3, bar 11 will have a ma length of 10 etc... The volume label only shows the most recent value, so the average of all the volume to date.

-mashume