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parameters_page

Parameters Page

A parameter, as defined in Ecolego, is a constant nominal value. For probabilistic analysis, probability density functions can be assigned for uncertain parameters.

User interface

To the left is a listing of all available parameters. When you select a parameter in the list, information (such as unit) and values for the parameter is displayed in the table to the right.

The list of parameters

The list presents all available parameters. Below the list is a section where you can search for specific parameters:

  • Name - Enter the name, or part of the name.
  • Category - Select a category for the parameter. 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 parameters for a specific model component.

Assigning parameter data

Information

The information section details specifics about the parameter. The description box can give you information about the data to enter, and the unit box tells you which unit is expected.

Entering data

The first column(s) of the table list indices for the parameter. For a contaminant-dependent (vector) parameter, the first column lists each contaminant. The subsequent columns allow you to enter values, probability density functions etc. When you click a cell in the Value or PDF column, an tool appears below the table.

Entering (nominal) values

The tool that appears when you click a cell in the Value table can help you convert a value to the unit required of the model.

  1. Enter the unit for the value you have in the From box.
  2. Enter your value in the Value box.
  3. Enter the target unit in the To box. This unit should be the same as listed in the Unit box in the Information section.
  4. Click apply to put the converted value in the cell.

Entering a probability density function (PDF)

Click a cell in the PDF column. Choose a probability density function from the Distribution functions drop-down list. Input fields will appear depending on the number of arguments required for the selected function.

The Upper trunc and Lower trunc fields are always available and can be used to truncate the function.

The editor contains several tools. By using the buttons in the toolbar you can select which tool to show.

Chart

The chart tool displays a graph of the current function. By using the buttons on the left hand side you can choose to plot

  • The PDF (Probability density function)
  • The CDF (Cumulative distribution function)
  • The survival function
  • The hazard function
  • The cumulative hazard function

Delimitors and calculated values from the Calculation tool are displayed in the graph using markers.

 Properties

Displays statistics on the currently selected function.

 Calculation

Allows you to calculate values and percentiles for the current function. These values are marked in the graph of the Chart tool.

 Information

Describes the currently selected function and it’s parameters.

References

parameters_page.txt · Last modified: 2019/11/18 13:34 (external edit)