Documentation
Parameters
In openLCA it is possible to assign processes and product systems different parameters, for example to handle with preliminary values. Parameters can easily be changed later in the modeling of product systems. A parameterised process can substitute hundreds of black-box processes.
openLCA distinguishes local and global parameters. Local and global parameters can overwrite each other; the direction can be defined under File > Preferences >Parameter settings (see Settings).
Notation for parameters
Simple mathematical calculations can be entered directly, e.g. a=6; b=2*5 + 4.
Many more complicated formulas can be used, but then need to be specified according to the Java Math specification.
A list of all provided functions is available here: http://java.sun.com/j2se/1.4.2/docs/api/java/lang/Math.html
To enter a mathematical, provided function, the prefix „Math.” is needed.
Local Parameters
If you open a process or a product system you find a tab „Parameters” at the bottom. If you click on it a table occurs where you can define parameters. For adding a new parameter, click on the plus symbol top right and fill in a name, a formula or a value, and a description (optional). The formula can refer to other parameters, but loops for parameters should be avoided (example: P1 uses P2, P2 uses P3, and P3 uses P1). Please make sure that you do not use commas for point numbers. Make also sure that you have specified arithmetic operators before bracket terms.
To delete parameters, mark one and click on the red cross top right.
Global Parameters
To define global parameters go to „File”, click on „Preferences” and go to the menu item „Global Parameters” under „Parameter settings”.
Click on the plus symbol to add a new global parameter. Fill in a name, enter a formula or a value for the parameter, and describe the parameter (optional). The formula can include other parameters, but loops for parameters should be avoided (example: P1 uses P2, P2 uses P3, and P3 uses P1), because of discontinuity. Please do not use commas for point numbers and specify arithmetic operators before bracket terms.
Finally click on „Apply” or „OK” to save the changes.
If you mark a parameter and click on the red cross you can delete it.
If you define both types of parameters, with identical names, be careful with overwriting! Under preferences, you can define whether global parameters overwrite local ones or vice versa.