From 0e53da5cc4e5952a58a004230b479ee6cb581b70 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=C3=A9a=20Saviot?= <lea.saviot@numworks.com>
Date: Tue, 5 Jun 2018 18:04:27 +0200
Subject: [PATCH] [apps/reg] Fix TrigonometricModel -> watch out for
 radians/degrees

---
 apps/regression/model/trigonometric_model.cpp | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/apps/regression/model/trigonometric_model.cpp b/apps/regression/model/trigonometric_model.cpp
index f40aef511..6380ddb9b 100644
--- a/apps/regression/model/trigonometric_model.cpp
+++ b/apps/regression/model/trigonometric_model.cpp
@@ -1,5 +1,6 @@
 #include "trigonometric_model.h"
 #include <math.h>
+#include <poincare/preferences.h>
 #include <assert.h>
 
 namespace Regression {
@@ -8,24 +9,26 @@ double TrigonometricModel::evaluate(double * modelCoefficients, double x) const
   double a = modelCoefficients[0];
   double b = modelCoefficients[1];
   double c = modelCoefficients[2];
-  return a*sin(b*x+c);
+  double radianX = Poincare::Preferences::sharedPreferences()->angleUnit() == Poincare::Expression::AngleUnit::Radian ? x : x * M_PI/180.0;
+  return a*sin(b*radianX+c);
 }
 
 double TrigonometricModel::partialDerivate(double * modelCoefficients, int derivateCoefficientIndex, double x) const {
   double a = modelCoefficients[0];
   double b = modelCoefficients[1];
   double c = modelCoefficients[2];
+  double radianX = Poincare::Preferences::sharedPreferences()->angleUnit() == Poincare::Expression::AngleUnit::Radian ? x : x * M_PI/180.0;
   if (derivateCoefficientIndex == 0) {
     // Derivate: sin(b*x+c)
-    return sin(b*x+c);
+    return sin(b*radianX+c);
   }
   if (derivateCoefficientIndex == 1) {
     // Derivate: x*a*cos(b*x+c);
-    return x*a*cos(b*x+c);
+    return radianX*a*cos(b*radianX+c);
   }
   if (derivateCoefficientIndex == 2) {
     // Derivate: a*cos(b*x+c)
-    return a*cos(b*x+c);
+    return a*cos(b*radianX+c);
   }
   assert(false);
   return 0.0;