From 9475649d2e3f4c447d5f47f32e85637fb2e1d186 Mon Sep 17 00:00:00 2001
From: Brandon Rodriguez <brodriguez8774@gmail.com>
Date: Sat, 30 Nov 2019 01:54:32 -0500
Subject: [PATCH] Update initialize to return bool based on feasability
---
resources/simplex/base.py | 2 +-
resources/simplex/initialize.py | 13 ++++---------
tests/resources/simplex/initialize.py | 3 ++-
3 files changed, 7 insertions(+), 11 deletions(-)
diff --git a/resources/simplex/base.py b/resources/simplex/base.py
index 2a9583b..9216b00 100644
--- a/resources/simplex/base.py
+++ b/resources/simplex/base.py
@@ -577,7 +577,7 @@ class SimplexBase():
"""
Initializes simplex.
"""
- self._initialize(debug=debug)
+ return self._initialize(debug=debug)
def pivot(self, old_basic_index, new_basic_index, debug=False):
"""
diff --git a/resources/simplex/initialize.py b/resources/simplex/initialize.py
index e26c2f4..c6eaf0d 100644
--- a/resources/simplex/initialize.py
+++ b/resources/simplex/initialize.py
@@ -68,14 +68,7 @@ class Initialize():
if self._vector_b[smallest_const_index] >= 0:
# Smallest value is non-negative. Is feasible.
# We already know values so return as-is.
- return (
- self._nonbasic_var_indexes,
- self._basic_var_indexes,
- self._matrix_a,
- self._vector_b,
- self._vector_c,
- self._obj_constant_index,
- )
+ return True
# If we got this far, then one or more constraint constants are negative.
# This means we have an invalid simplex starting point, and want to correct it.
@@ -177,9 +170,11 @@ class Initialize():
self._parent._b_array = b_array
self._parent._n_array = n_array
+ return True
+
else:
# No solution exists for original simplex.
logger.info('Could not determine solution for simplex problem. Problem is likely infeasible.')
- return None
+ return False
diff --git a/tests/resources/simplex/initialize.py b/tests/resources/simplex/initialize.py
index 0c57b10..7704933 100644
--- a/tests/resources/simplex/initialize.py
+++ b/tests/resources/simplex/initialize.py
@@ -35,9 +35,10 @@ class TestInitialize(unittest.TestCase):
self.assertEqual(self.simplex._n_array, [0, 1])
# Call initialize method to test.
- self.simplex.initialize()
+ initialize_results = self.simplex.initialize()
# Test initial values "initialize" method.
+ self.assertTrue(initialize_results)
self.assertEqual(self.simplex._matrix_a, [
[9/5, 0, 1, (-1 + 4/5)], # We use -1/5th represented as a float. Technically is the same value.
[-1/5, 1, 0, -1/5],
--
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