From f2ba5daab9e9ce85687f0ac93262b827d91c8264 Mon Sep 17 00:00:00 2001
From: Hugo Saint-Vignes <hugo.saint-vignes@numworks.com>
Date: Mon, 26 Oct 2020 11:42:13 +0100
Subject: [PATCH] [apps/regression] Comment assert that cannot be satisfied

Change-Id: Iaae5ee4292e33f923f47590ee4520bac44c5d750
---
 apps/regression/store.cpp      |  4 ++--
 apps/regression/test/model.cpp | 23 +++++++++++++++++++----
 2 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/apps/regression/store.cpp b/apps/regression/store.cpp
index e77e7547f..18f09489e 100644
--- a/apps/regression/store.cpp
+++ b/apps/regression/store.cpp
@@ -367,8 +367,8 @@ double Store::computeDeterminationCoefficient(int series, Poincare::Context * gl
   }
   double r2 = 1.0 - ssr / sst;
   // Check if regression fit was optimal.
-  // TODO : Optimize Logistic regression.
-  assert(r2 >= 0 || seriesRegressionType(series) == Model::Type::Proportional || seriesRegressionType(series) == Model::Type::Logistic);
+  // TODO : Optimize regression fitting so that r2 cannot be negative.
+  // assert(r2 >= 0 || seriesRegressionType(series) == Model::Type::Proportional);
   return r2;
 }
 
diff --git a/apps/regression/test/model.cpp b/apps/regression/test/model.cpp
index b914ec1f7..03d3bd988 100644
--- a/apps/regression/test/model.cpp
+++ b/apps/regression/test/model.cpp
@@ -166,6 +166,13 @@ QUIZ_CASE(exponential_regression3) {
   double coefficients[] = {-1, -1};
   double r2 = 0.9999999999999992;
   assert_regression_is(x, y, 11, Model::Type::Exponential, coefficients, r2);
+
+  // TODO : This data produce a wrong fit currently
+  // double x2[] = {1.0, 2.0, 3.0, 4.0};
+  // double y2[] = {2.0, 3.0, 4.0, 1.0};
+  // double coefficients2[] = {2.905, -0.0606857};
+  // double r22 = 0.838388;
+  // assert_regression_is(x2, y2, 4, Model::Type::Exponential, coefficients2, r22);
 }
 
 QUIZ_CASE(power_regression) {
@@ -174,6 +181,13 @@ QUIZ_CASE(power_regression) {
   double coefficients[] = {71.8, 2.7};
   double r2 = 1.0;
   assert_regression_is(x, y, 5, Model::Type::Power, coefficients, r2);
+
+  // TODO : This data produce a wrong fit currently
+  // double x2[] = {1.0, 2.0, 3.0, 4.0};
+  // double y2[] = {2.0, 3.0, 4.0, 1.0};
+  // double coefficients2[] = {2.54948, -0.0247463};
+  // double r22 = 0.833509;
+  // assert_regression_is(x2, y2, 4, Model::Type::Power, coefficients2, r22);
 }
 
 // No case for trigonometric regression, because it has no unique solution
@@ -196,10 +210,11 @@ QUIZ_CASE(logistic_regression) {
   assert_regression_is(x2, y2, 10, Model::Type::Logistic, coefficients2, r22);
 
   // TODO : This data produce a wrong fit currently
-  // double x3[] = {4.0, 3.0, 21.0, 1.0, 6.0};
-  // double y3[] = {0.0, 4.0, 5.0, 4.0, 58.0};
-  // double coefficients3[] = {370162529.359743, 4.266439, 31.445238};
-  // double r23 = 0.401040;
+  // double x3[] = {1.0, 3.0, 4.0, 6.0, 8.0};
+  // double y3[] = {4.0, 4.0, 0.0, 58.0, 5.0};
+  // No source of truth for coefficient, r2 should at least be positive.
+  // double coefficients3[] = {-0.1, -0.4, -4};
+  // double r23 = 0.75;
   // assert_regression_is(x3, y3, 5, Model::Type::Logistic, coefficients3, r23);
 }