Parameter modifications can be widely utilized when creating a model. Parameterizing a model allows flexibility when creating a configurable LCA model.
There are multiple fields throughout the application, that accept parameter inputs. All created parameters are listed on the Parameters page and can be edited there.
To create a parameter from the Parameters page:
Go to the Parameters page.
Click Create new parameter
Then the parameter will be added to the list and you can change the name, add an expression and a comment (optional).
The Parameters page has the following features:
Expression defines how the parameter is calculated. If you enter a number, then it will be the parameter’s value (see below), but you can also enter a calculation formula. When creating a parameter or writing a value in any of the quantified fields such as ‘Amount’, ’Allocation percentage’ etc. there are some expressions which are allowed. These expressions are:
• Plus (+), minus (-), division (/), modulo (%), multiplication (*), power (^).
• Equal (=), unequal (<>).
• Smaller than (<), smaller or equal to (<=), larger than (>), larger or equal to (>=).
• Scientific notation (2.3E-7).
• IF statements (2 IF Parameter1 == 4 ELSE 1).
• AND statements (2 IF(Parameter1 == 4 AND parameter2 == 2) ELSE 5).
• OR statements (2 IF(Parameter1 == 4 OR parameter2 == 2) ELSE 5).
• MAX and MIN functions (MAX(2;5)), (MIN(2;5)).
Note! For more than 2 arguments, please adapt the function to (MAX(1;MAX(2;5))), (MIN(1;MIN(2;5)))
• Parentheses for resolving sub expressions (2*(4-3)).
Value field shows the value which will be used for further calculations, this is especially interesting when you create a large expression with using other parameters or complex formulas.
Used by button, shows if and where the parameter has been used in your model.
Finally, if you would like to delete a parameter, click on the waste bin symbol
.
A parameter can be used in any value field throughout the application. To call a parameter in a value field:
Type the exact parameter name in value field.
When you click out of the field, you can recognize the parametrized field by the sign
.
Parameter tips:
The comment field is good to use for keeping track of the unit of the parameter.
When editing a process you can also fill in the name of a new parameter and the default value will again be 1 until it is edited in the parameter page.
You can also create parameters in the Model Builder.
If you change the name of the parameter on the Parameters page, the name of the parameter will be changed in all the fields in which it is used throughout the application.