From 2aea72d22815a50492532b3913bc3eb34a75e4de Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89milie=20Feral?= <emilie.feral@numworks.com>
Date: Fri, 30 Dec 2016 12:19:11 +0100
Subject: [PATCH] [apps/regression] Add a method to data model

Change-Id: Ic08de61e87a0886dfb2520bf9292ba1176b3d84a
---
 apps/regression/data.cpp | 5 +++++
 apps/regression/data.h   | 1 +
 2 files changed, 6 insertions(+)

diff --git a/apps/regression/data.cpp b/apps/regression/data.cpp
index ffa96c5bd..976991b2e 100644
--- a/apps/regression/data.cpp
+++ b/apps/regression/data.cpp
@@ -177,6 +177,10 @@ float Data::yIntercept() {
   return yMean() - slope()*xMean();
 }
 
+float Data::yValueForXValue(float x) {
+  return slope()*x+yIntercept();
+}
+
 float Data::maxXValue() {
   float max = -FLT_MAX;
   for (int k = 0; k < m_numberOfPairs; k++) {
@@ -219,6 +223,7 @@ float Data::minYValue() {
 
 void Data::initCursorPosition() {
   m_xCursorPosition = (m_xMin+m_xMax)/2.0f;
+  m_yCursorPosition = yValueForXValue(m_xCursorPosition);
 }
 
 void Data::initWindowParameters() {
diff --git a/apps/regression/data.h b/apps/regression/data.h
index 94d5d3b90..c8faf1404 100644
--- a/apps/regression/data.h
+++ b/apps/regression/data.h
@@ -44,6 +44,7 @@ public:
   float covariance();
   float slope();
   float yIntercept();
+  float yValueForXValue(float x);
 
   constexpr static int k_maxNumberOfPairs = 500;
 private: