I was wondering if someone can help me. ThinkOrSwim has an indicator called relative strength which compares the stock to the SPX. Would anyone know how to apply a 20 period EMA to this indicator? Any help would be greatly appreciated. Thanks

declare lower;

#RS
input CorrelationWithSecurity = "SPX";
def close2 = close(CorrelationWithSecurity);

plot RS = if close2 == 0 then 0 else close/close2;
RS.setDefaultColor(GetColor(6));

def sr = CompoundValue("historical data" = RS, "visible data" = if isNaN(sr[1]) then RS else sr[1]);
plot SRatio = sr;
SRatio.setDefaultColor(GetColor(5));

#EMA of RS
input price = close;
input length = 20;
input displace = 0;
input showBreakoutSignals = no;

plot AvgExp = ExpAverage(RS[-displace], length);
plot UpSignal = RS crosses above AvgExp;
plot DownSignal = RS crosses below AvgExp;

UpSignal.SetHiding(!showBreakoutSignals);
DownSignal.SetHiding(!showBreakoutSignals);

AvgExp.SetDefaultColor(GetColor(1));
UpSignal.SetDefaultColor(Color.UPTICK);
UpSignal.SetPaintingStrategy(PaintingStrategy.BOOLEAN_ARROW_UP);
DownSignal.SetDefaultColor(Color.DOWNTICK);
DownSignal.SetPaintingStrategy(PaintingStrategy.BOOLEAN_ARROW_DOWN);

This is exactly what I was looking for..... Thank you so much, its greatly appreciated!