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Working with arrays

  • arraydef.mos: Defining arrays: sparse and dense arrays; deleting array entries; multiple indices; array access functions
  • arrayinit.mos: Array initialization from a text file (requires arrayinit.dat)
  • autoarray.mos: Working with automatic arrays
  • chess2.mos: Indexing arrays by variables
Further explanation of this example: 'Mosel User Guide', Section 8.1 Arrays

Source Files
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Data Files


   Mosel User Guide Example Problems

   file arraydef.mos 
   Defining arrays.
   - sparse and dense arrays
   - deleting array entries
   - multiple indices
   - array access functions
   (c) 2010 Fair Isaac Corporation
       author: S. Heipcke, Jul. 2010, rev. Mar. 2022
model "array definition"

  A1: array(1..3) of integer         ! Fixed size array
  F = {"a","b","c"}
  A2: array(F) of real               ! Fixed size array
  A3: array(R:range) of integer      ! Dense array with nknown index set
  A4: dynamic array(F) of real       ! Sparse array
  A5: hashmap array(F) of real       ! Sparse array

 writeln("A1:", A1, " A2:", A2, " A3:", A3, " A4:", A4, " A5:", A5)

! Using the array initialization operator
 A1::[10,20,30]                      ! Range indices are known
 A2::(["a","b","c"])[1.1, 2.5, 3.9]  ! String indices must be stated
 A3::(1..3)[10,20,30]                ! Indices are not known upfront

! Redefine an entry

! This line leads to an 'index out of range' error
! A2("d"):=5.1
 forall(f in F) A4(f):= 10*random    ! Value assignment
 forall(f in F) A5(f):= A4(f)
 delcell(A4("a")); delcell(A5("b"))  ! Deleting entries from sparse arrays
 writeln("A1:", A1, " A2:", A2, " A3:", A3, " A4:", A4, " A5:", A5)

 delcell(A4); reset(A5)              ! Deleting the whole array contents
 writeln("A4:", A4, " A5:", A5)

!**** Multiple indices and array access functions ****

  C: array(range, set of string, set of real) of integer
  D: array(1..5) of array(range, set of string) of real

 C(5,"ab",1.5):= 10
 C(5,"dce",2.5):= 15
 writeln("C=", C, ", size of C: ", C.size, ", number of dimensions: ", C.nbdim)
 forall(i in 1..getnbdim(C))
  writeln("  index set ", i, " = ", C.index(i), " (size:", C.index(i).size, ")")

! Alternative syntax for accessing entries of 'array of array' structures
 D(1,7,"a"):= 2.8;  D(3,7,"b"):= 1.4
 D(1)(9,"a"):= 20;  D(4)(1,"b"):= 3.5

 writeln("D: ", D)

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