====== Options Page ======

For some models, the model creator has provided calculation options.

Example 1: A model uses a partition coefficient //Kd//. Depending on the situation, the model offers different ways of calculating this coefficient.

  - User enters a value for the partition coefficient as a parameter.
  - Model calculates the value using a regression expression.
  - Model calculates the value using a QSAR model.

Example 2: A model has an input transfer of contaminants into the system. Options are provided for:

  - Chronic contamination. The user enters a value for a parameter.
  - Time-varying contamination. The user enters time dependent values for a lookup table.
  - Periodic contamination: The model calculates the transfer by using a periodic function.

===== User interface =====

This window displays a list of all available options to the left. When selecting an option in this list, details about the option is presented in the table to the right.

===== The list of options =====

The list presents all available options. For very large models, the number of options can be great. Beneath the list is a section where you can filter out items from the list:

  * **Name** - Enter the name, or part of the name.
  * **Category** - Select a category for the option. The categories are part of the model, so this list is empty unless the model creator has assigned categories to the options.
  * **Sub-system** - Select a sub-system to only display options for a specific model component.

===== Making options =====

When you select an option, details about the specific option is presented in the right hand side of the screen. Depending on whether the option is for a scalar, 1 dimensional or 2 dimensional value the table will add a column for each dimension.

To make an option, click a table cell in the **Expression** column. A drop-down menu will let you select from a list of available option items.

For non-scalar values, you can make different options for different indices. For instance, you might want to calculate a partition coefficient one way for a metallic substance, and another way for an organic substance.

==== The default row ====

In most cases, you want to make the same option for all indices. For instance, in a model with the contaminants Lead, Arsenic and Cadmium and the option //Release rate option//, you would typically use the same type of release for all contaminants.

The first row of the table is titled **Default**. When you select an option for this row, it will apply to all indices. By selecting options directly for other indices, you can override the default option.

===== References =====

  * [[Introduction_to_Ecolego_Player|Introduction to Ecolego Player]]
  * [[Ecolego_Player_Wiki|Ecolego Player Wiki]]