Creating a Parameter
Description
To create a new parameter in the Model Tree:
Select the position in a Declaration Section where the new parameter should be inserted
From the Edit menu select Insert – Parameter
Enter a name for the new parameter (if you are creating a multi-dimensional parameter, you can type the indices of each dimension as well)
Press
<Enter>
to create the new parameter (or press<Esc>
to abort the operation)
The newly created parameter is now ready for use, but you probably want to specify some additional attributes. To modify the attributes of the newly created parameter:
Press
<Enter>
or double click on the parameter node.
The most commonly used attributes of a parameter are discussed below.
INDEX DOMAIN
: TheINDEX DOMAIN
attribute should be specified in order to declare indexed parameters. Thewizard will display the Set Dependency Tree of your model and allows you to select one or more indices.
RANGE
: TheRANGE
attribute should be specified in order to restrict the values to certain intervals. Thewizard will let you either select one of the predefined ranges, like
Real
,Nonnegative
,Nonpositive
,Integer
, orBinary
, or specify a (parametric) interval range.UNIT
: TheUNIT
attribute is used to specify the unit in which the parameter value is measured. By specifying a unit, AIMMS is able to perform automatic unit conversions and unit consistency checks. Thewizard will let you select a unit and quantity from the list made up from your model quantities and units together with the information in the AIMMS SI unit base.
DEFAULT
: TheDEFAULT
attribute should be used in order to specify a nonzero default value for the parameter. Note that AIMMS will explicitly store all values that are non-default.DEFINITION
: TheDEFINITION
attribute can (and should) be used to specify the definition of an identifier by means of a global relationship. AIMMS stores the result of a definition and recomputes it only when necessary.
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