From dce7a3caded533584307d313a0f84c86af0c3316 Mon Sep 17 00:00:00 2001
From: Jens Ahrensfeld <jens@jayfield.org>
Date: Mon, 20 Jun 2022 10:55:26 +0000
Subject: [PATCH] - do not use StatisticsProvider - make cheap and accurate
 trackers

git-svn-id: http://moon:8086/svn/software/trunk/libsrc/cpp@1040 b431acfa-c32f-4a4a-93f1-934dc6c82436
---
 radio/metrics/Tracker.cpp | 42 ++++++++++++++++++++++++++++-----------
 radio/metrics/Tracker.hpp | 19 +++++++++++-------
 2 files changed, 42 insertions(+), 19 deletions(-)

diff --git a/radio/metrics/Tracker.cpp b/radio/metrics/Tracker.cpp
index 2e5237d..5657f5b 100644
--- a/radio/metrics/Tracker.cpp
+++ b/radio/metrics/Tracker.cpp
@@ -1,14 +1,20 @@
 #include "Tracker.hpp"
 
+#include <iostream>
+
+using namespace std;
 
 namespace Radio
 {
 namespace Metrics
 {
 
-Tracker::Tracker(IMinMax const &prov_minMax)
-: m_prov_minMax(prov_minMax)
+Tracker::Tracker(RealScalar rho, RealScalar smoothness)
+: m_mags(NUM_QUADRRANTS)
+, m_rho(rho)
+, m_smoothness(smoothness)
 {
+	m_mags = 0;
 }
 
 Tracker::~Tracker()
@@ -22,18 +28,30 @@ ComplexScalar const* Tracker::trackers() const
 
 void Tracker::process(ComplexScalar const &x)
 {
-	radio_float_t alpha = 0.002;
-	radio_float_t beta = 1.0 - alpha;
-	radio_float_t min_i = m_prov_minMax.min_i();
-	radio_float_t min_q = m_prov_minMax.min_q();
-	radio_float_t max_i = m_prov_minMax.max_i();
-	radio_float_t max_q = m_prov_minMax.max_q();
+	size_t qu = getQuadrant(x);
+	m_mags[qu] *= m_rho;
 
-	m_trackers[0] = beta*m_trackers[0] + alpha*ComplexScalar(max_i, min_q);
-	m_trackers[1] = beta*m_trackers[1] + alpha*ComplexScalar(max_i, max_q);
-	m_trackers[2] = beta*m_trackers[2] + alpha*ComplexScalar(min_i, max_q);
-	m_trackers[3] = beta*m_trackers[3] + alpha*ComplexScalar(min_i, min_q);
+	RealScalar mag = abs(x);
+	if (mag > m_mags[qu])
+	{
+		m_mags[qu] = mag;
+		m_trackers[qu] = m_smoothness*x + (RealScalar(1.0)-m_smoothness)*m_trackers[qu];
+	}
+}
 
+size_t Tracker::getQuadrant(ComplexScalar const &x)
+{
+	size_t result = 0;
+
+	if (x.real() < 0)
+	{
+		result |= 0x02;
+	}
+	if (x.imag() < 0)
+	{
+		result |= 0x01;
+	}
+	return result;
 }
 
 } // Metrics
diff --git a/radio/metrics/Tracker.hpp b/radio/metrics/Tracker.hpp
index 1efa3e4..aaf9a33 100644
--- a/radio/metrics/Tracker.hpp
+++ b/radio/metrics/Tracker.hpp
@@ -4,6 +4,7 @@
 #pragma once
 
 #include <cpp/radio/Vector.hpp>
+#include <cpp/radio/statistics/SlidingMinMax.hpp>
 #include "IMinMax.hpp"
 
 namespace Radio
@@ -13,16 +14,20 @@ namespace Metrics
 
 class Tracker
 {
+	static const size_t NUM_QUADRRANTS = 4;
 public:
-    Tracker(IMinMax const &statsProvider);
-    virtual ~Tracker();
-    void process(ComplexScalar const &x);
-    ComplexScalar const* trackers() const;
-    
+	Tracker(RealScalar rho, RealScalar smoothness=0.5);
+	virtual ~Tracker();
+	void process(ComplexScalar const &x);
+	ComplexScalar const* trackers() const;
+	
 private:
-    IMinMax const &m_prov_minMax;
-	ComplexScalar m_trackers[4];
+	RVec m_mags;
+	RealScalar m_rho;
+	RealScalar m_smoothness;
 
+	ComplexScalar m_trackers[NUM_QUADRRANTS];
+	size_t getQuadrant(ComplexScalar const &x);
 };
 
 } // Metrics