• Name of the model & options• Parameters• Declarations (decision variables, arrays, etc.)• Data input• Objective function• Constraints• Output & results

How to write a model in Mosel Xpress-IVE

1

model ModelName

options …

uses “mmxprs”

… !other sections

end-model

For comment write “!” before the commented word

How to write a model (1) Name of the model & options

2

model ModelName

!parameters section first

parameters

MAXTIME=300

USE_LOG=false

!...

end-parameters

!Rest of the model (declarations, statements, etc.)

end-model

How to write a model (2) Parameters – optional section

3

declarations

Variable : mpvar

VariableArray : array() of mpvar

IntegerVariable : mpvar

BinaryVariable : mpvar

end-declarations

IntegerVariable is_integer !when integer variable

BinaryVariable is_binary !when binary variable

4

How to write a model (3) Declarations (variables, arrays, etc.)

declarations

UnitCost : array(1..10) of integer

end-declarations

initializations from “Filename”

UnitCost;

end-initializations

5

How to write a model (4) Data input – optional section

Cost:=2*x1+3*x2

!...constraints

minimize(Cost) !you don’t need to declare Cost

or

Profit:=2*x1+3*x2

!...constraints

miximize(Profit) !you don’t need to declare Profit

6

How to write a model (5) Objective function

! simple constraint

X1+3*X2-5*X3<=8

! multiple constraints using loop

forall(i in 1..10) Z(i)=1

! sum constraint

sum(i in 1..10) X(i)<=B

! multiple sum constraints using loop

forall(i in 1..5) sum (j in 1..10) X(i,j)=1

7

How to write a model (6) Constraints

853 321 xxx

10,..,11 iforzi

Bxi

i

10

1

5,..,1110

1

iforxj

ij

! Value of objective function - getobjval

writeln(“Objective value: “, getobjval)

! Value of decision variable

writeln(“X1 = “,getsol(X1))

! Values of decision variables in array using loop

forall(i in 1..M)

writeln(" Y(“, i,") = “, getsol(Y(i)))

8

How to write a model (7) Output & results