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Conditional creation of decision variables

If an array of decision variables of type mpvar is created as a dynamic array then its entries must be created explicitly using the subroutine create (doesx.mos). It is recommended to add an explicit 'exists' condition in loops over sparse arrays to improve the performance of the enumeration (doesx1.mos). Through the automatic finalization mechanism or via an explicit call to finalize a dynamic set is turned into a constant set, all subsequently declared arrays that are indexed by this set will be created as static arrays (doesx2.mos).

Further explanation of this example: 'Mosel User Guide', Section 3.3 Conditional generation

Source Files
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Data Files


   Mosel User Guide Example Problems

   file doesx.mos
   Working with dynamic arrays of variables.
   (c) 2008 Fair Isaac Corporation
       author: Bob Daniel, 2001, rev. Sep. 2018

model doesx
 public declarations
  IR = 1..15
  WHICH: set of integer
  x: dynamic array(IR) of mpvar
  Obj,C: linctr

! Read data from file
 initializations from 'doesx.dat'

! Create the x variables that exist
 forall(i in WHICH) create(x(i))

! Build a little model to show what esists
 Obj:= sum(i in IR) x(i)
 C:= sum(i in IR) i * x(i) >= 5

 exportprob(0, "", Obj)    ! Display the resulting problem definition in Mosel

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