From b93a87abf2ff30d0d6e4f87a0957b39c0724f75c Mon Sep 17 00:00:00 2001
From: iliya <iliya.saroukhanian@etu.hesge.ch>
Date: Mon, 1 Apr 2024 17:23:20 +0200
Subject: [PATCH] cleanup: refactored Aliya's ideas
---
src/simplexe.py | 57 +++++++++++++++++++++++++++++++++++++++++--------
1 file changed, 48 insertions(+), 9 deletions(-)
diff --git a/src/simplexe.py b/src/simplexe.py
index 2247d32..c6631f1 100644
--- a/src/simplexe.py
+++ b/src/simplexe.py
@@ -255,19 +255,32 @@ class Simplexe:
# to iterate over basic variables do:
for rowId, baseColId in enumerate(self.__basicVariables):
- if self.RHS[rowId] / self.__tableau[rowId][baseColId] < 0:
+ if self.__getBasicVariableValue(rowId, baseColId) < 0:
return False
- # raise Exception(
- # 'Not implemented', 'Simplexe.__isSolutionFeasible: missing code to be implemented.')
return True
# returns index of entering col Id
# return None or -1 if there is pivot
def __selectEnteringColumn(self):
# find an entering column for pivot => return -1 if none is found!
- raise Exception(
- 'Not implemented', 'Simplexe.__selectEnteringColumn: missing code to be implemented.')
+
+ # print(self.__tableau[0])
+ # for rowId, baseColId in enumerate(self.__basicVariables):
+ # print(self.__tableau[rowId, baseColId])
+ #
+
+ # This maybe ain't that dumb but it works half the time which is weird
+ # if self.__PivotCount > self.AMatrix.shape[1] - 1:
+ # return -1
+ #
+ # return self.__PivotCount
+
+ if np.size(self.__tableau[-1, :-1][np.where(self.__tableau[-1, :-1]
+ < 0)]) == 0:
+ return -1
+
+ return np.argmin(self.__tableau[-1, :-1])
# returns leaving row ID
# return None or -1 if there is pivot (sets optimisation status accoringly before returning)
@@ -276,8 +289,21 @@ class Simplexe:
# iterate using :
# rowCount = self.TableauRowCount - 2 if self.IsPhaseI else self.TableauRowCount - 1
# for index in range(rowCount):
- raise Exception(
- 'Not implemented', 'Simplexe.__selectLeavingRow: missing code to be implemented.')
+
+ rowCount = self.TableauRowCount - 2 if self.IsPhaseI else \
+ self.TableauRowCount - 1
+
+ lhs = self.__tableau[:rowCount, pivotColId]
+ rhs = self.__tableau[:rowCount, -1]
+
+ ratios = rhs / lhs
+
+ candidates = np.where(ratios > 0, ratios, np.inf)
+
+ if len((np.unique(candidates))) == 0:
+ return -1
+
+ return candidates.argmin()
def __pivotTableau(self, pivotIDs):
if pivotIDs is None or pivotIDs[0] < 0 or pivotIDs[1] < 0:
@@ -302,8 +328,21 @@ class Simplexe:
# iterate using
# pivotRow = self.__tableau[pivotRowId, :] / pivotVal
# for rowId in range(self.TableauRowCount):
- raise Exception(
- 'Not implemented', 'Simplexe.__pivotTableau: missing code to be implemented.')
+
+ # Calculer la ligne du pivot normalisée (avoir la valeur 1 à la colonne du pivot)
+ pivotRow = self.__tableau[pivotRowId, :] / pivotVal
+
+ # Pour chaque ligne autre que le pivot
+ for rowId in range(self.TableauRowCount):
+ if rowId != pivotRowId:
+ # Mettre la colonne du pivot à 0
+ multiplier = self.__tableau[rowId, pivotColId]
+ self.__tableau[rowId, :] -= multiplier * pivotRow
+
+ self.__tableau[pivotRowId, :] = pivotRow
+
+ # raise Exception(
+ # 'Not implemented', 'Simplexe.__pivotTableau: missing code to be implemented.')
# For a given unfeasible initial problem, this method creates the corresponding Tableau of the Phase I, then launches the optimization of Phase I
def initPhaseI(self, simplexe):
--
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