From 65383970a7aeb35e8557cc495ac18ad66433d29e Mon Sep 17 00:00:00 2001
From: Ahmet Inan <inan@aicodix.de>
Date: Sun, 24 Feb 2019 19:42:54 +0100
Subject: [PATCH] added prev, alpha init and samples() to EMA

---
 ema.hh | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/ema.hh b/ema.hh
index 210d699..4a23a4d 100644
--- a/ema.hh
+++ b/ema.hh
@@ -22,13 +22,17 @@ class EMA
 		return x-VALUE(1)+sqrt(x*(x-VALUE(4))+VALUE(3));
 	}
 public:
-	EMA() : prev(0), alpha(1)
+	constexpr EMA(TYPE prev = TYPE(0), VALUE alpha = VALUE(1)) : prev(prev), alpha(alpha)
 	{
 	}
 	void cutoff(int n, int N)
 	{
 		alpha = cutoff_alpha(n, N);
 	}
+	void samples(int s)
+	{
+		alpha = VALUE(1) / VALUE(s);
+	}
 	TYPE operator()(TYPE input)
 	{
 		return prev = lerp(alpha, prev, input);