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{
	TASC DEC 2025
	One Euro Filter Indicator
	From "1€ Filter: A Simple Speed-Based Low-Pass Filter
	For Noisy Input In Interactive Systems" (CHI 2012)
	By Georges Casiez, Nicolas Roussel, and Daniel Vogel
	(C) 2025 John F. Ehlers
}

inputs:
	PeriodMin( 10 ), // Minimum cutoff frequency
	BetaVal( 0.2 ); // Responsiveness factor

variables:
	Price( 0 ),
	PeriodDX( 10 ),
	AlphaDX( 0 ),
	SmoothedDX( 0 ),
	Cutoff( 0 ),
	Alpha3( 0 ),
	Smoothed( 0 );

Price = Close;
AlphaDX = 2 * 3.14159 / (4 * 3.14159 + PeriodDX);

// Initialize
if CurrentBar = 1 then 
begin
	SmoothedDX = 0;
	Smoothed = Price;
end;

// EMA the Delta Price
SmoothedDX = AlphaDX * (Price - Price[1]) + (1 -
 AlphaDX) * SmoothedDX[1];
// Adjust cutoff period based on fraction of the rate of 
// change
Cutoff = PeriodMin + BetaVal * AbsValue(SmoothedDX);
// Compute adaptive alpha
Alpha3 = 2*3.14159 / (4 * 3.14159 + Cutoff);
//Adaptive smoothing
Smoothed = Alpha3 * Price + (1 - Alpha3) * Smoothed[1];
//Plot
Plot1( Smoothed );