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.

1. User enters a value for the partition coefficient as a parameter.
2. Model calculates the value using a regression expression.
3. 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:

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

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 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.

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.

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.

• Introduction to Ecolego Player
• Ecolego Player Wiki