Imports System.IO
Imports Mosel
' Example of accessing sets in Mosel
Module ExSet
Public Sub RunExSet(ByVal Log As TextWriter)
Dim mosel As XPRM
Dim model As XPRMModel
Dim mySet As XPRMSet
Dim first, last, i As Integer
' Initialise Mosel
mosel = XPRM.Init
' Load a BIM file
model = mosel.LoadModel("Models/burglari.bim")
' And run it
model.Run()
' Get the model object named 'ITEMS'
' (it must be a set)
mySet = model.FindIdentifier("ITEMS")
If (Not mySet.IsEmpty) Then
' Items in a set are indexed by numbers
' So get the first and last indexes
first = mySet.FirstIndex
last = mySet.LastIndex
Log.WriteLine("Elements of set ITEMS:")
For i = first To last
Log.Write(" {0}, ", mySet.GetAsString(i))
Next
Log.WriteLine()
' We've written this out explicitly to demonstrate set access, but the
' set actually knows how to output itself. Uncomment the following line
' to see this in action
' Log.WriteLine(mySet.ToString)
If (mySet.GetIndex("CD player") < 0) Then
Log.WriteLine("'CD player' is not contained in 'ITEMS'")
End If
End If
End Sub
End Module
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Imports System.IO
Imports Mosel
' Example of using arrays with index sets; different ways of enumerating arrays
Module ExAs
Public Sub RunExAs(ByVal Log As TextWriter)
Dim mosel As XPRM
Dim model As XPRMModel
Dim varr As XPRMArray
Dim sets() As XPRMSet
Dim vindex() As XPRMValue
Dim indices() As Integer
Dim dimensions As Integer
Dim i As Integer
' Initialise Mosel
mosel = XPRM.Init
' Load a BIM file
model = mosel.LoadModel("Models/trans.bim")
' Run the model
model.Run()
' Get the model object named 'x'
' It must be an array
varr = model.FindIdentifier("x")
' Get the number of dimensions of the array
dimensions = varr.Dim
' Get the indexing sets
sets = varr.IndexSets
' We could use varr.ToString to obtain a summary of the array contents,
' but instead we'll demonstrate how to interate over the array's content
' directly
Log.WriteLine("1. Logic entries:")
' Get the first entry of varr
For Each indices In varr.Indices
Log.Write("x(")
' Get the values for this index
vindex = varr.DereferenceIndex(indices)
' Now, output them. Note that we could call the utility method
' varr.IndexToString(indices) instead of doing all this, but again
' this wouldn't be such a useful demonstration
If (dimensions > 1) Then
For i = 0 To dimensions - 2
Log.Write(vindex(i).AsString & ",")
Next
End If
Log.Write(vindex(dimensions - 1).AsString & "), ")
Next
Log.WriteLine()
' Now enumerate over the true entries - in a dense array this would
' be no different from the previous demonstration, so only do it for
' a dynamic array
If (varr.IsDynamic) Then
Log.WriteLine("2. True entries:")
For Each indices In varr.TEIndices
' Functionally the same as above, but this time we'll demonstrate
' using IndexToStringrasExAs
Log.Write("x" & varr.IndexToString(indices) & ", ")
Next
End If
Log.WriteLine()
model.Reset()
End Sub
End Module
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Imports System.IO
Imports Mosel
' Example of accessing problems and solution information
Module ExProb
Public Sub RunExProb(ByVal Log As TextWriter)
Dim mosel As XPRM
Dim model As XPRMModel
Dim varr, darr As XPRMArray
Dim lgrade As XPRMLinCtr
' Initialise Mosel
mosel = XPRM.Init
' Load a BIM file
model = mosel.LoadModel("Models/blend2.bim")
' Run the model (it includes optimization)
model.Run()
' Export the problem to a file in LP format (maximization)
model.ExportProblem("p", "blend")
' Test whether optimal is found
If (model.ProblemStatus = XPRMProblemStatus.PB_OPTIMAL) Then
Log.WriteLine("Solution is optimal.")
End If
' Print out the objective function value
Log.WriteLine("Objective value: {0}", model.ObjectiveValue)
' Get the model objects 'x' and 'COST' (both arrays)
varr = model.FindIdentifier("x")
darr = model.FindIdentifier("COST")
' For each entry in array var, display solution value and corresponding
' cost
Dim indices() As Integer
For Each indices In varr.Indices
Log.WriteLine( _
"x{0}={1} (COST: {2})", _
varr.IndexToString(indices), _
varr.Get(indices).AsMPVar.Solution, _
darr.GetAsReal(indices) _
)
Next
' Get the model object 'LoGrade'
' It must be a reference to a linear constraint
lgrade = CType(model.FindIdentifier("LoGrade"), XPRMReference).Value.AsLinCtr
Log.WriteLine( _
"LoGrade: activity={0}, dual={1}", _
lgrade.Activity, _
lgrade.Dual _
)
model.Reset()
End Sub
End Module
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