From bb69ad4b6ef2e7077591b0a8bf22ac18b62e8ba1 Mon Sep 17 00:00:00 2001
From: Brandon Rodriguez <brodriguez8774@gmail.com>
Date: Tue, 26 Nov 2019 23:02:44 -0500
Subject: [PATCH] Partial implementation of "Simplex" algorithm function

---
 resources/simplex/base.py              |  2 +-
 resources/simplex/run_simplex.py       | 97 ++++++++++++++++++++++++++
 tests/resources/simplex/base.py        |  2 +-
 tests/resources/simplex/run_simplex.py | 24 +++++++
 4 files changed, 123 insertions(+), 2 deletions(-)
 create mode 100644 resources/simplex/run_simplex.py
 create mode 100644 tests/resources/simplex/run_simplex.py

diff --git a/resources/simplex/base.py b/resources/simplex/base.py
index 130c06d..7c101f1 100644
--- a/resources/simplex/base.py
+++ b/resources/simplex/base.py
@@ -5,7 +5,7 @@ Assignment: Linear Programming Simplex Algorithm
 Author: Brandon Rodriguez
 
 
-Implementation of the "Simplex" for Linear Programming problems.
+Implementation of base logic for "Simplex" to solve Linear Programming problems.
 
 
 General Terminology to Remember:
diff --git a/resources/simplex/run_simplex.py b/resources/simplex/run_simplex.py
new file mode 100644
index 0000000..145d0e7
--- /dev/null
+++ b/resources/simplex/run_simplex.py
@@ -0,0 +1,97 @@
+"""
+Date: 11-22-19
+Class: CS5310
+Assignment: Linear Programming Simplex Algorithm
+Author: Brandon Rodriguez
+
+
+Implementation of the "Simplex" function for Linear Programming Simplex problems.
+"""
+
+# System Imports.
+import copy
+
+# User Class Imports.
+from resources import logging as init_logging
+
+
+# Initialize Logger.
+logger = init_logging.get_logger(__name__)
+
+
+class RunSimplex():
+    def __init__(self, parent, *args, **kwargs):
+        # Get calling parent. We use this to pull parent data on __call__.
+        self._parent = parent
+
+        # Parent data values to set later.
+        self._matrix_a = None
+        self._vector_b = None
+        self._vector_c = None
+        self._obj_constant_index = None
+        self._basic_var_indexes = None
+        self._nonbasic_var_indexes = None
+
+    def __call__(self, old_basic_col, new_basic_col, *args, **kwargs):
+        # Run pivot function.
+        return self._simplex()
+
+    def _simplex(self):
+        # Run "Initialize-Simplex" function before we do any work.
+        self._parent.initialize()
+
+        # Get parent data, after initialized.
+        matrix_a = self._parent._matrix_a
+        vector_b = self._parent._vector_b
+        vector_c = self._parent._vector_c
+        obj_constant_index = self._parent._obj_constant_index
+        basic_var_indexes = self._parent._b_array
+        nonbasic_var_indexes = self._parent._n_array
+
+        # Create loop to continually improve simplex until optimized.
+        still_optimizable = True
+        while still_optimizable:
+            still_optimizable = False
+            highest_obj_index = -1
+            # Check that we actually can still optimize values.
+            for col_index in range(len(nonbasic_var_indexes)):
+                # Check if value is greater than 0.
+                if vector_c[col_index] > 0:
+                    still_optimizable = True
+                    # Check if current index is larger than previously found one.
+                    if highest_obj_index == -1 or vector_c[col_index] > vector_c[highest_obj_index]:
+                        highest_obj_index = col_index
+
+            # Check that we found something to optimize.
+            if still_optimizable:
+                self._optimize_on_index(highest_obj_index)
+
+    def _optimize_on_index(self, col_index):
+
+        # Get parent data, after initialized.
+        matrix_a = self._parent._matrix_a
+        vector_b = self._parent._vector_b
+        vector_c = self._parent._vector_c
+        obj_constant_index = self._parent._obj_constant_index
+        basic_var_indexes = self._parent._b_array
+        nonbasic_var_indexes = self._parent._n_array
+
+        # Loop through all rows, finding best one to pivot on.
+        delta = []
+        for row_index in range(len(matrix_a)):
+            # Check that we can divide.
+            if matrix_a[row_index][col_index] > 0:
+                delta.append(vector_b[col_index] / matrix_a[row_index][col_index])
+            else:
+                # Less than 1. Can't divide.
+                delta.append(-1)
+
+        # Now check to see which row we actually use.
+        smallest_valid_index = -1
+        for row_index in range(len(delta)):
+            if delta[row_index] > 0:
+                # Check if current index is smaller than previous one.
+                if smallest_valid_index == -1 or delta[row_index] < delta[smallest_valid_index]:
+                    smallest_valid_index = row_index
+
+        # Now pivot on our found values.
diff --git a/tests/resources/simplex/base.py b/tests/resources/simplex/base.py
index 9c23829..b8549d7 100644
--- a/tests/resources/simplex/base.py
+++ b/tests/resources/simplex/base.py
@@ -5,7 +5,7 @@ Assignment: Linear Programming Simplex Algorithm
 Author: Brandon Rodriguez
 
 
-Tests for implementation of the "Simplex" algorithm.
+Tests for base logic of the "Simplex" algorithm.
 """
 
 # System Imports.
diff --git a/tests/resources/simplex/run_simplex.py b/tests/resources/simplex/run_simplex.py
new file mode 100644
index 0000000..3b5f8a4
--- /dev/null
+++ b/tests/resources/simplex/run_simplex.py
@@ -0,0 +1,24 @@
+"""
+Date: 11-22-19
+Class: CS5310
+Assignment: Linear Programming Simplex Algorithm
+Author: Brandon Rodriguez
+
+
+Tests for "Simplex" function implementation of the Simplex algorithm.
+"""
+
+# System Imports.
+import unittest
+
+# User Class Imports.
+from resources.simplex.base import SimplexBase
+
+
+class TestPivot(unittest.TestCase):
+    def setUp(self):
+        self.simplex = SimplexBase()
+
+    def test__run_simplex(self):
+        # Setup initial simplex.
+        pass
-- 
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