Copyright	(c) Junaid Rasheed 2020-2023
License	BSD-3
Maintainer	jrasheed178@gmail.com
Stability	experimental
Safe Haskell	Safe-Inferred
Language	Haskell2010

Linear.Simplex.Util

Description

Helper functions for performing the two-phase simplex method.

Synopsis

isMax :: ObjectiveFunction -> Bool
simplifySystem :: [PolyConstraint] -> [PolyConstraint]
dictionaryFormToTableau :: Dict -> Tableau
tableauInDictionaryForm :: Tableau -> Dict
extractObjectiveValue :: Maybe Result -> Maybe SimplexNum
combineVarLitMapSums :: VarLitMapSum -> VarLitMapSum -> VarLitMapSum
foldDictValue :: [DictValue] -> DictValue
foldVarLitMap :: [VarLitMap] -> VarLitMap
insertPivotObjectiveToDict :: PivotObjective -> Dict -> Dict
showT :: Show a => a -> Text
logMsg :: (MonadIO m, MonadLogger m) => LogLevel -> Text -> m ()
extractTableauValues :: Tableau -> Map Var SimplexNum
extractDictValues :: Dict -> Map Var SimplexNum

Documentation

isMax :: ObjectiveFunction -> Bool Source #

Is the given ObjectiveFunction to be Maximized?

simplifySystem :: [PolyConstraint] -> [PolyConstraint] Source #

Simplifies a system of PolyConstraints by first calling simplifyPolyConstraint, then reducing LEQ and GEQ with same LHS and RHS (and other similar situations) into EQ, and finally removing duplicate elements using nub.

dictionaryFormToTableau :: Dict -> Tableau Source #

Converts a Dict to a Tableau using dictEntryToTableauEntry. FIXME: maybe remove this line. The basic variables will have a coefficient of 1 in the Tableau.

tableauInDictionaryForm :: Tableau -> Dict Source #

Converts a Tableau to a Dict. We do this by isolating the basic variable on the LHS, ending up with all non basic variables and a SimplexNum constant on the RHS.

extractObjectiveValue :: Maybe Result -> Maybe SimplexNum Source #

If this function is given Nothing, return Nothing. Otherwise, we lookup the Integer given in the first item of the pair in the map given in the second item of the pair. This is typically used to extract the value of the ObjectiveFunction after calling twoPhaseSimplex.

combineVarLitMapSums :: VarLitMapSum -> VarLitMapSum -> VarLitMapSum Source #

Combines two 'VarLitMapSums together by summing values with matching keys

foldDictValue :: [DictValue] -> DictValue Source #

foldVarLitMap :: [VarLitMap] -> VarLitMap Source #

insertPivotObjectiveToDict :: PivotObjective -> Dict -> Dict Source #

showT :: Show a => a -> Text Source #

logMsg :: (MonadIO m, MonadLogger m) => LogLevel -> Text -> m () Source #

extractTableauValues :: Tableau -> Map Var SimplexNum Source #

extractDictValues :: Dict -> Map Var SimplexNum Source #