From 9c455957f2640cf65f4206f60d8b2e9659d1e65f Mon Sep 17 00:00:00 2001
From: SimpleArt <71458112+SimpleArt@users.noreply.github.com>
Date: Mon, 9 Nov 2020 16:02:01 -0500
Subject: [PATCH] Edge case for converting fitness to minimization

Avoid catastrophic cancellations
---
 src/EasyGA.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/EasyGA.py b/src/EasyGA.py
index 1399ea4..11642bc 100644
--- a/src/EasyGA.py
+++ b/src/EasyGA.py
@@ -141,7 +141,10 @@ class GA(Attributes):
         if self.target_fitness_type == 'max': return fitness_value
         max_fitness = self.population.get_chromosome(-1).get_fitness()
         min_fitness = self.population.get_chromosome(0).get_fitness()
-        return max_fitness - fitness_value + min_fitness
+        if min_fitness / max_fitness < 1e-5:
+            return -fitness_value
+        else:
+            return max_fitness - fitness_value + min_fitness
 
 
     def print_generation(self):