diff --git a/resources/simplex/simplex.py b/resources/simplex/simplex.py
index c2620ee7b8a1e44ab917259ee8e9ad2785bc235a..3ff0e608b8bd49caf2036843538afd87c7f797d2 100644
--- a/resources/simplex/simplex.py
+++ b/resources/simplex/simplex.py
@@ -52,6 +52,8 @@ class Simplex():
self._constants = None
self._obj_func = None
self._obj_constant_index = None
+ self._basic_var_indexes = None
+ self._nonbasic_var_indexes = None
def read_data_from_json(self, json_file_location):
logger.info('')
@@ -98,16 +100,42 @@ class Simplex():
else:
raise KeyError('Could not find key "objective" or "objective_function" in JSON data.')
+ # Check if "basic_vars" key exists.
+ if 'basic_vars' in json_data:
+ basic_vars = json_data['basic_vars']
+ elif 'basic_variables' in json_data:
+ basic_vars = json_data['basic_variables']
+ else:
+ basic_vars = None
+
+ # Check if "non_basic_vars" key exists.
+ if 'non_basic_vars' in json_data:
+ non_basic_vars = json_data['non_basic_vars']
+ elif 'non_basic_variables' in json_data:
+ non_basic_vars = json_data['non_basic_variables']
+ else:
+ non_basic_vars = None
+
# Data has been parsed. Now attempt to set it.
- self.set_simplex_values(matrix_a, vector_b, vector_c)
+ self.set_simplex_values(matrix_a, vector_b, vector_c, basic_vars=basic_vars, non_basic_vars=non_basic_vars)
- def set_simplex_values(self, matrix_a, vector_b, vector_c):
+ def set_simplex_values(self, matrix_a, vector_b, vector_c, basic_vars=None, non_basic_vars=None):
"""
Sets values for simplex.
:param matrix_a: Matrix of constraint equation coefficients.
:param vector_b: Vector of constraint constants.
:param vector_c: Vector of objective function coefficients.
+ :param basic_vars: Optional array of basic variable column indexes.
+ :param non_basic_vars: Optional array of non-basic variable column indexes.
"""
+ # Reset all values to None.
+ self._matrix_a = None
+ self._constants = None
+ self._obj_func = None
+ self._obj_constant_index = None
+ self._basic_var_indexes = None
+ self._nonbasic_var_indexes = None
+
# Check that values are of expected types.
if not isinstance(matrix_a, list) or not isinstance(vector_b, list) or not isinstance(vector_c, list):
raise TypeError('Expected Constraint Equations, Constraint Constants, and Objective function to be lists.')
@@ -134,7 +162,7 @@ class Simplex():
# Check that vector_c length is equal to (or one greater than) matrix_a row length.
if len(vector_c) == matrix_row_length:
# vector_c is exactly equal to row length.
- logger.info('Assuming constant for objective function is currently 0.')
+ logger.info('Assuming constant for objective function is initially 0.')
self._obj_func = vector_c
self._obj_func.append(0)
elif len(vector_c) - 1 == matrix_row_length:
@@ -150,6 +178,125 @@ class Simplex():
self._constants = vector_b
self._obj_constant_index = len(self._obj_func) - 1
+ # Check if optional basic var arguments were provided.
+ if basic_vars is not None:
+ if isinstance(basic_vars, list):
+ self._basic_var_indexes = basic_vars
+ else:
+ raise TypeError('The "basic_vars" argument is expected to be of type list.')
+
+ # Check if optional non-basic var arguments were provided.
+ if non_basic_vars is not None:
+ if isinstance(non_basic_vars, list):
+ self._nonbasic_var_indexes = non_basic_vars
+ else:
+ raise TypeError('The "non_basic_vars" argument is expected to be of type list.')
+
+ # Finally, determine/set basic and nonbasic variables.
+ self._determine_basic_variables()
+ self._determine_nonbasic_variables()
+
+ def _determine_basic_variables(self):
+ """
+ Determines (and if needed, sets) all basic variables for given constraints.
+ """
+ # Check that values exist. If they do, we will assume that this was called from "set_simplex_values" and we
+ # don't need to re-validate.
+ if self._matrix_a is None or self._constants is None or self._obj_func is None:
+ raise ValueError('Values are not yet set. This function should only be called from "set_simplex_values".')
+
+ # Check if basic variables are already defined.
+ if isinstance(self._basic_var_indexes, list) and len(self._basic_var_indexes) > 0:
+ # Basic variables are already defined. No reason to proceed.
+ return None
+
+ rows_with_slack = []
+ self._basic_var_indexes = []
+ expected_basic_var_count = len(self._matrix_a)
+
+ # Loop through one column at a time of all rows, checking for potential instances of a basic variable.
+ for col_index in range(len(self._matrix_a[0])):
+ col_valid_for_slack = True
+ found_col_non_zero = False
+ non_zero_index = 0
+ for row_index in range(len(self._matrix_a)):
+
+ # Only continue if col values so far meet criteria for a basic variable.
+ if col_valid_for_slack:
+
+ # If this col has a basic var, then all coefficients will be either 0 or 1.
+ cur_coefficient = self._matrix_a[row_index][col_index]
+ if cur_coefficient != 0 and cur_coefficient != 1:
+ # Found a non-0 and non-1 value. Col no longer valid for slack.
+ col_valid_for_slack = False
+
+ # Col may still be valid for slack variable. Check if non-zero value, and handle accordingly.
+ elif cur_coefficient == 1:
+
+ # Current coefficient is non-zero value. Either this is a basic var or col is not slack.
+ if found_col_non_zero:
+ # Another value of 1 was already found.
+ # This means we have two values of 1 and this col is no longer valid for slack.
+ col_valid_for_slack = False
+
+ else:
+ # This is the first value of 1 found in column. May be slack.
+ found_col_non_zero = True
+ non_zero_index = row_index
+
+ # Now that we checked all rows in current column, determine if we have a slack col.
+ if col_valid_for_slack and found_col_non_zero:
+ # We found exactly one non-0 value of 1 in the column. Our saved index was a slack variable.
+ rows_with_slack.append(non_zero_index)
+ self._basic_var_indexes.append(col_index)
+
+ # We've checked all rows and columns. Check our number of found basic variables.
+ if len(self._basic_var_indexes) > expected_basic_var_count:
+ # We found more possible basic variables than exist rows.
+ # While this is technically a valid matrix format, it so gives us no way to determine which columns contain
+ # the initial basic variables. User needs to define it themselves to proceed.
+ raise ValueError('Only detected {0} constraint equations, yet found {1} possible basic variables. If the '
+ 'provided equations are correct, then please manually define "basic_variables" value.')
+ elif len(self._basic_var_indexes) < expected_basic_var_count:
+ # Found less basic variables than exist rows. We need to add additional columns for the missing variables.
+ for row_index in range(len(self._matrix_a)):
+ # Find all rows without a slack variable.
+ if row_index not in rows_with_slack:
+ # Given row does not have a slack variable. Add a new column to the end of all rows.
+ self._matrix_a[row_index].append(1)
+ for new_row_index in range(len(self._matrix_a)):
+ if new_row_index != row_index:
+ self._matrix_a[new_row_index].append(0)
+
+ # Add new column to objective function too. But make sure to keep objective constant at end of list.
+ self._obj_func.insert((len(self._obj_func) - 1), 0)
+ self._obj_constant_index += 1
+
+ # Save column location of basic var.
+ self._basic_var_indexes.append(len(self._matrix_a[0]) - 1)
+
+ def _determine_nonbasic_variables(self):
+ """
+ Determines all non-basic variables for given constraints.
+ """
+ # Check that values exist. If they do, we will assume that this was called from "set_simplex_values" and we
+ # don't need to re-validate.
+ if self._matrix_a is None or self._constants is None or self._obj_func is None:
+ raise ValueError('Values are not yet set. This function should only be called from "set_simplex_values".')
+
+ # Check if nonbasic variables are already defined.
+ if isinstance(self._nonbasic_var_indexes, list) and len(self._nonbasic_var_indexes) > 0:
+ # Nonbasic variables are already defined. No reason to proceed.
+ return None
+
+ if self._basic_var_indexes is None or len(self._basic_var_indexes) == 0:
+ raise ValueError('Values are not yet set. This function should only be called from "set_simplex_values".')
+
+ # If we got this far, assume we have a proper count of basic variables and record all nonbasic columns.
+ self._nonbasic_var_indexes = []
+ for col_index in range(len(self._matrix_a[0])):
+ if col_index not in self._basic_var_indexes:
+ self._nonbasic_var_indexes.append(col_index)
def display_tableau(self):
logger.info('')
diff --git a/tests/resources/simplex/simplex.py b/tests/resources/simplex/simplex.py
index 6ee3bd85b5fa37f57e13cb949677352858015fdb..cefe8a71fbebe6f360149db224cc94284044bcc2 100644
--- a/tests/resources/simplex/simplex.py
+++ b/tests/resources/simplex/simplex.py
@@ -21,52 +21,78 @@ class TestSimplex(unittest.TestCase):
def test__parse_from_json__success(self):
with self.subTest('Using first set of keys.'):
- self.simplex.parse_json_data({
+ self.simplex._parse_json_data({
'constraints': [
[1],
],
'constants': [2],
'objective': [3],
+ 'basic_vars': [4],
+ 'non_basic_vars': [5],
})
self.assertEqual(self.simplex._matrix_a, [[1]])
self.assertEqual(self.simplex._constants, [2])
self.assertEqual(self.simplex._obj_func, [3, 0])
self.assertEqual(self.simplex._obj_constant_index, 1)
+ self.assertEqual(self.simplex._basic_var_indexes, [4])
+ self.assertEqual(self.simplex._nonbasic_var_indexes, [5])
with self.subTest('Using second set of keys.'):
- self.simplex.parse_json_data({
+ self.simplex._parse_json_data({
'constraint_matrix': [
[1],
],
'constraint_constants': [2],
'objective_function': [3],
+ 'basic_variables': [4],
+ 'non_basic_variables': [5],
})
self.assertEqual(self.simplex._matrix_a, [[1]])
self.assertEqual(self.simplex._constants, [2])
self.assertEqual(self.simplex._obj_func, [3, 0])
self.assertEqual(self.simplex._obj_constant_index, 1)
+ self.assertEqual(self.simplex._basic_var_indexes, [4])
+ self.assertEqual(self.simplex._nonbasic_var_indexes, [5])
+
+ with self.subTest('Objective constant provided.'):
+ self.simplex._parse_json_data({
+ 'constraint_matrix': [
+ [1],
+ ],
+ 'constraint_constants': [2],
+ 'objective_function': [3, 5],
+ 'basic_variables': [4],
+ 'non_basic_variables': [5],
+ })
+ self.assertEqual(self.simplex._matrix_a, [[1]])
+ self.assertEqual(self.simplex._constants, [2])
+ self.assertEqual(self.simplex._obj_func, [3, 5])
+ self.assertEqual(self.simplex._obj_constant_index, 1)
+ self.assertEqual(self.simplex._basic_var_indexes, [4])
+ self.assertEqual(self.simplex._nonbasic_var_indexes, [5])
+
def test__parse_from_json__failure(self):
with self.subTest('No valid keys.'):
with self.assertRaises(KeyError):
- self.simplex.parse_json_data({})
+ self.simplex._parse_json_data({})
with self.subTest('Only "constants" key.'):
with self.assertRaises(KeyError):
- self.simplex.parse_json_data({
+ self.simplex._parse_json_data({
'constraints': [],
})
with self.subTest('No "objective" key.'):
with self.assertRaises(KeyError):
- self.simplex.parse_json_data({
+ self.simplex._parse_json_data({
'constraints': [],
'constants': [],
})
with self.subTest('Key "constraints" is not list.'):
with self.assertRaises(TypeError):
- self.simplex.parse_json_data({
+ self.simplex._parse_json_data({
'constraints': '',
'constants': [],
'objective': [],
@@ -74,7 +100,7 @@ class TestSimplex(unittest.TestCase):
with self.subTest('Key "constants" is not list.'):
with self.assertRaises(TypeError):
- self.simplex.parse_json_data({
+ self.simplex._parse_json_data({
'constraints': [],
'constants': '',
'objective': [],
@@ -82,7 +108,7 @@ class TestSimplex(unittest.TestCase):
with self.subTest('Key "objective" is not list.'):
with self.assertRaises(TypeError):
- self.simplex.parse_json_data({
+ self.simplex._parse_json_data({
'constraints': [],
'constants': [],
'objective': '',
@@ -90,7 +116,7 @@ class TestSimplex(unittest.TestCase):
with self.subTest('Key "constraints" is empty list.'):
with self.assertRaises(ValueError):
- self.simplex.parse_json_data({
+ self.simplex._parse_json_data({
'constraints': [],
'constants': [1],
'objective': [1],
@@ -98,7 +124,7 @@ class TestSimplex(unittest.TestCase):
with self.subTest('Key "constants" is empty list.'):
with self.assertRaises(ValueError):
- self.simplex.parse_json_data({
+ self.simplex._parse_json_data({
'constraints': [1],
'constants': [],
'objective': [1],
@@ -106,7 +132,7 @@ class TestSimplex(unittest.TestCase):
with self.subTest('Key "objective" is empty list.'):
with self.assertRaises(ValueError):
- self.simplex.parse_json_data({
+ self.simplex._parse_json_data({
'constraints': [1],
'constants': [1],
'objective': [],
@@ -114,7 +140,7 @@ class TestSimplex(unittest.TestCase):
with self.subTest('Constraint matrix is not list of lists.'):
with self.assertRaises(TypeError):
- self.simplex.parse_json_data({
+ self.simplex._parse_json_data({
'constraints': [1],
'constants': [1],
'objective': [1],
@@ -122,7 +148,7 @@ class TestSimplex(unittest.TestCase):
with self.subTest('Constraint matrix rows do not match up.'):
with self.assertRaises(ValueError):
- self.simplex.parse_json_data({
+ self.simplex._parse_json_data({
'constraints': [
[1],
[1,2],
@@ -133,7 +159,7 @@ class TestSimplex(unittest.TestCase):
with self.subTest('Constraint matrix and constraint constants do not match up.'):
with self.assertRaises(ValueError):
- self.simplex.parse_json_data({
+ self.simplex._parse_json_data({
'constraints': [
[1],
[1],
@@ -144,7 +170,7 @@ class TestSimplex(unittest.TestCase):
with self.subTest('Objective function less than length of constraint matrix rows.'):
with self.assertRaises(ValueError):
- self.simplex.parse_json_data({
+ self.simplex._parse_json_data({
'constraints': [
[1, 2],
[1, 2],
@@ -155,7 +181,7 @@ class TestSimplex(unittest.TestCase):
with self.subTest('Objective function greater than length of constraint matrix rows.'):
with self.assertRaises(ValueError):
- self.simplex.parse_json_data({
+ self.simplex._parse_json_data({
'constraints': [
[1],
[1],
@@ -163,3 +189,212 @@ class TestSimplex(unittest.TestCase):
'constants': [1, 1],
'objective': [1, 2, 3],
})
+
+ with self.subTest('Variable "basic_vars" is provided, but not list.'):
+ with self.assertRaises(TypeError):
+ self.simplex._parse_json_data({
+ 'constraints': [
+ [1],
+ [1],
+ ],
+ 'constants': [1, 1],
+ 'objective': [1],
+ 'basic_vars': '',
+ })
+
+ with self.subTest('Variable "non_basic_vars" is provided, but not list.'):
+ with self.assertRaises(TypeError):
+ self.simplex._parse_json_data({
+ 'constraints': [
+ [1],
+ [1],
+ ],
+ 'constants': [1, 1],
+ 'objective': [1],
+ 'non_basic_vars': '',
+ })
+
+ def test__set_simplex_values(self):
+ # Note that type validation is already partially tested in above "parse_from_json" tests.
+ # Thus, here we more specifically test logic for setting and accessing of basic/nonbasic variables.
+ with self.subTest('No basic vars provided.'):
+ self.simplex.set_simplex_values([
+ [1, 1, 1],
+ [1, 1, 1],
+ [1, 1, 1],
+ ],
+ [1, 1, 1],
+ [1, 1, 1],
+ )
+ self.assertEqual(self.simplex._matrix_a, [
+ [1, 1, 1, 1, 0, 0],
+ [1, 1, 1, 0, 1, 0],
+ [1, 1, 1, 0, 0, 1],
+ ])
+ self.assertEqual(self.simplex._constants, [1, 1, 1])
+ self.assertEqual(self.simplex._obj_func, [1, 1, 1, 0, 0, 0, 0])
+ self.assertEqual(self.simplex._obj_constant_index, 6)
+ self.assertEqual(self.simplex._basic_var_indexes, [3, 4, 5])
+ self.assertEqual(self.simplex._nonbasic_var_indexes, [0, 1, 2])
+
+ with self.subTest('Some basic vars implicitly provided.'):
+ self.simplex.set_simplex_values([
+ [1, 0, 1, 0, 1],
+ [1, 1, 1, 0, 1],
+ [1, 0, 1, 1, 1],
+ ],
+ [1, 1, 1],
+ [1, 0, 1, 0, 1],
+ )
+ self.assertEqual(self.simplex._matrix_a, [
+ [1, 0, 1, 0, 1, 1],
+ [1, 1, 1, 0, 1, 0],
+ [1, 0, 1, 1, 1, 0],
+ ])
+ self.assertEqual(self.simplex._constants, [1, 1, 1])
+ self.assertEqual(self.simplex._obj_func, [1, 0, 1, 0, 1, 0, 0])
+ self.assertEqual(self.simplex._obj_constant_index, 6)
+ self.assertEqual(self.simplex._basic_var_indexes, [1, 3, 5])
+ self.assertEqual(self.simplex._nonbasic_var_indexes, [0, 2, 4])
+
+ with self.subTest('Some basic vars implicitly provided - With obj constant.'):
+ self.simplex.set_simplex_values([
+ [1, 0, 1, 0, 1],
+ [1, 1, 1, 0, 1],
+ [1, 0, 1, 1, 1],
+ ],
+ [1, 1, 1],
+ [1, 0, 1, 0, 1, 5],
+ )
+ self.assertEqual(self.simplex._matrix_a, [
+ [1, 0, 1, 0, 1, 1],
+ [1, 1, 1, 0, 1, 0],
+ [1, 0, 1, 1, 1, 0],
+ ])
+ self.assertEqual(self.simplex._constants, [1, 1, 1])
+ self.assertEqual(self.simplex._obj_func, [1, 0, 1, 0, 1, 0, 5])
+ self.assertEqual(self.simplex._obj_constant_index, 6)
+ self.assertEqual(self.simplex._basic_var_indexes, [1, 3, 5])
+ self.assertEqual(self.simplex._nonbasic_var_indexes, [0, 2, 4])
+
+ with self.subTest('All basic vars implicitly provided at start.'):
+ self.simplex.set_simplex_values([
+ [0, 1, 0, 1, 1, 1],
+ [1, 0, 0, 1, 1, 1],
+ [0, 0, 1, 1, 1, 1],
+ ],
+ [1, 1, 1],
+ [0, 0, 0, 1, 1, 1],
+ )
+ self.assertEqual(self.simplex._matrix_a, [
+ [0, 1, 0, 1, 1, 1],
+ [1, 0, 0, 1, 1, 1],
+ [0, 0, 1, 1, 1, 1],
+ ])
+ self.assertEqual(self.simplex._constants, [1, 1, 1])
+ self.assertEqual(self.simplex._obj_func, [0, 0, 0, 1, 1, 1, 0])
+ self.assertEqual(self.simplex._obj_constant_index, 6)
+ self.assertEqual(self.simplex._basic_var_indexes, [0, 1, 2])
+ self.assertEqual(self.simplex._nonbasic_var_indexes, [3, 4, 5])
+
+ with self.subTest('All basic vars implicitly provided at start - With obj constant.'):
+ self.simplex.set_simplex_values([
+ [0, 1, 0, 1, 1, 1],
+ [1, 0, 0, 1, 1, 1],
+ [0, 0, 1, 1, 1, 1],
+ ],
+ [1, 1, 1],
+ [0, 0, 0, 1, 1, 1, 5],
+ )
+ self.assertEqual(self.simplex._matrix_a, [
+ [0, 1, 0, 1, 1, 1],
+ [1, 0, 0, 1, 1, 1],
+ [0, 0, 1, 1, 1, 1],
+ ])
+ self.assertEqual(self.simplex._constants, [1, 1, 1])
+ self.assertEqual(self.simplex._obj_func, [0, 0, 0, 1, 1, 1, 5])
+ self.assertEqual(self.simplex._obj_constant_index, 6)
+ self.assertEqual(self.simplex._basic_var_indexes, [0, 1, 2])
+ self.assertEqual(self.simplex._nonbasic_var_indexes, [3, 4, 5])
+
+ with self.subTest('All basic vars implicitly provided at end.'):
+ self.simplex.set_simplex_values([
+ [1, 1, 1, 0, 1, 0],
+ [1, 1, 1, 0, 0, 1],
+ [1, 1, 1, 1, 0, 0],
+ ],
+ [1, 1, 1],
+ [1, 1, 1, 0, 0, 0],
+ )
+ self.assertEqual(self.simplex._matrix_a, [
+ [1, 1, 1, 0, 1, 0],
+ [1, 1, 1, 0, 0, 1],
+ [1, 1, 1, 1, 0, 0],
+ ])
+ self.assertEqual(self.simplex._constants, [1, 1, 1])
+ self.assertEqual(self.simplex._obj_func, [1, 1, 1, 0, 0, 0, 0])
+ self.assertEqual(self.simplex._obj_constant_index, 6)
+ self.assertEqual(self.simplex._basic_var_indexes, [3, 4, 5])
+ self.assertEqual(self.simplex._nonbasic_var_indexes, [0, 1, 2])
+
+ with self.subTest('All basic vars implicitly provided at end - With objective constant.'):
+ self.simplex.set_simplex_values([
+ [1, 1, 1, 0, 1, 0],
+ [1, 1, 1, 0, 0, 1],
+ [1, 1, 1, 1, 0, 0],
+ ],
+ [1, 1, 1],
+ [1, 1, 1, 0, 0, 0, 5],
+ )
+ self.assertEqual(self.simplex._matrix_a, [
+ [1, 1, 1, 0, 1, 0],
+ [1, 1, 1, 0, 0, 1],
+ [1, 1, 1, 1, 0, 0],
+ ])
+ self.assertEqual(self.simplex._constants, [1, 1, 1])
+ self.assertEqual(self.simplex._obj_func, [1, 1, 1, 0, 0, 0, 5])
+ self.assertEqual(self.simplex._obj_constant_index, 6)
+ self.assertEqual(self.simplex._basic_var_indexes, [3, 4, 5])
+ self.assertEqual(self.simplex._nonbasic_var_indexes, [0, 1, 2])
+
+ with self.subTest('All basic vars explicitly provided at start.'):
+ self.simplex.set_simplex_values([
+ [0, 1, 0, 1, 1, 1],
+ [1, 0, 0, 1, 1, 1],
+ [0, 0, 1, 1, 1, 1],
+ ],
+ [1, 1, 1],
+ [0, 0, 0, 1, 1, 1],
+ basic_vars=[0, 1, 2],
+ )
+ self.assertEqual(self.simplex._matrix_a, [
+ [0, 1, 0, 1, 1, 1],
+ [1, 0, 0, 1, 1, 1],
+ [0, 0, 1, 1, 1, 1],
+ ])
+ self.assertEqual(self.simplex._constants, [1, 1, 1])
+ self.assertEqual(self.simplex._obj_func, [0, 0, 0, 1, 1, 1, 0])
+ self.assertEqual(self.simplex._obj_constant_index, 6)
+ self.assertEqual(self.simplex._basic_var_indexes, [0, 1, 2])
+ self.assertEqual(self.simplex._nonbasic_var_indexes, [3, 4, 5])
+
+ with self.subTest('All basic vars explicitly provided at end.'):
+ self.simplex.set_simplex_values([
+ [1, 1, 1, 0, 1, 0],
+ [1, 1, 1, 0, 0, 1],
+ [1, 1, 1, 1, 0, 0],
+ ],
+ [1, 1, 1],
+ [1, 1, 1, 0, 0, 0],
+ basic_vars=[3, 4, 5],
+ )
+ self.assertEqual(self.simplex._matrix_a, [
+ [1, 1, 1, 0, 1, 0],
+ [1, 1, 1, 0, 0, 1],
+ [1, 1, 1, 1, 0, 0],
+ ])
+ self.assertEqual(self.simplex._constants, [1, 1, 1])
+ self.assertEqual(self.simplex._obj_func, [1, 1, 1, 0, 0, 0, 0])
+ self.assertEqual(self.simplex._obj_constant_index, 6)
+ self.assertEqual(self.simplex._basic_var_indexes, [3, 4, 5])
+ self.assertEqual(self.simplex._nonbasic_var_indexes, [0, 1, 2])