From 7f2e52f6a6978ae66637034eee3bafea87aaf8d5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=C3=A9a=20Saviot?= <lea.saviot@numworks.com>
Date: Mon, 2 Sep 2019 17:55:47 +0200
Subject: [PATCH] [apps/proba] Fix result consistency

Scenario: Poisson distribution, lambda = 4, P(x < ?) = 1.3E-112
---
 apps/probability/calculation/left_integral_calculation.cpp  | 2 ++
 apps/probability/calculation/right_integral_calculation.cpp | 2 ++
 apps/probability/distribution/distribution.cpp              | 6 +++---
 poincare/src/solver.cpp                                     | 2 +-
 4 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/apps/probability/calculation/left_integral_calculation.cpp b/apps/probability/calculation/left_integral_calculation.cpp
index 7af5ff214..f589ce4e8 100644
--- a/apps/probability/calculation/left_integral_calculation.cpp
+++ b/apps/probability/calculation/left_integral_calculation.cpp
@@ -50,10 +50,12 @@ void LeftIntegralCalculation::compute(int indexKnownElement) {
     if (!std::isnan(m_upperBound)) {
       double currentResult = m_distribution->cumulativeDistributiveFunctionAtAbscissa(m_upperBound);
       if (std::fabs(currentResult - m_result) < std::pow(10.0, - Poincare::Preferences::LargeNumberOfSignificantDigits)) {
+        m_result = currentResult;
         return;
       }
     }
     m_upperBound = m_distribution->cumulativeDistributiveInverseForProbability(&m_result);
+    m_result = m_distribution->cumulativeDistributiveFunctionAtAbscissa(m_upperBound);
     if (std::isnan(m_upperBound)) {
       m_result = NAN;
     }
diff --git a/apps/probability/calculation/right_integral_calculation.cpp b/apps/probability/calculation/right_integral_calculation.cpp
index 5e7160606..08903df47 100644
--- a/apps/probability/calculation/right_integral_calculation.cpp
+++ b/apps/probability/calculation/right_integral_calculation.cpp
@@ -50,10 +50,12 @@ void RightIntegralCalculation::compute(int indexKnownElement) {
     if (m_distribution->authorizedValueAtIndex(m_lowerBound, 0)) {
       double currentResult = m_distribution->rightIntegralFromAbscissa(m_lowerBound);
       if (std::fabs(currentResult - m_result) < std::pow(10.0, - Poincare::Preferences::LargeNumberOfSignificantDigits)) {
+        m_result = currentResult;
         return;
       }
     }
     m_lowerBound = m_distribution->rightIntegralInverseForProbability(&m_result);
+    m_result = m_distribution->rightIntegralFromAbscissa(m_lowerBound);
     if (std::isnan(m_lowerBound)) {
       m_result = NAN;
     }
diff --git a/apps/probability/distribution/distribution.cpp b/apps/probability/distribution/distribution.cpp
index 8379a94a5..090ce3e90 100644
--- a/apps/probability/distribution/distribution.cpp
+++ b/apps/probability/distribution/distribution.cpp
@@ -49,14 +49,14 @@ double Distribution::finiteIntegralBetweenAbscissas(double a, double b) const {
 }
 
 double Distribution::cumulativeDistributiveInverseForProbability(double * probability) {
-  if (*probability >= 1.0) {
+  if (*probability > 1.0 - DBL_EPSILON) {
     return INFINITY;
   }
   if (isContinuous()) {
     return 0.0;
   }
-  if (*probability <= 0.0) {
-    return 0.0;
+  if (*probability < DBL_EPSILON) {
+    return -1.0;
   }
   return Poincare::Solver::CumulativeDistributiveInverseForNDefinedFunction<double>(probability,
         [](double k, Poincare::Context * context, Poincare::Preferences::ComplexFormat complexFormat, Poincare::Preferences::AngleUnit angleUnit, const void * context1, const void * context2, const void * context3) {
diff --git a/poincare/src/solver.cpp b/poincare/src/solver.cpp
index 08580bab1..4ac77a0a6 100644
--- a/poincare/src/solver.cpp
+++ b/poincare/src/solver.cpp
@@ -208,7 +208,7 @@ Coordinate2D<double> Solver::IncreasingFunctionRoot(double ax, double bx, double
 template<typename T>
 T Solver::CumulativeDistributiveInverseForNDefinedFunction(T * probability, ValueAtAbscissa evaluation, Context * context, Preferences::ComplexFormat complexFormat, Preferences::AngleUnit angleUnit, const void * context1, const void * context2, const void * context3) {
   T precision = sizeof(T) == sizeof(double) ? DBL_EPSILON : FLT_EPSILON;
-  assert(*probability <= (((T)1.0) - precision) && *probability > precision);
+  assert(*probability <= (((T)1.0) - precision) && *probability >= precision);
   T p = 0.0;
   int k = 0;
   T delta = 0.0;