# MERLIN-Expo

### Site Tools

parameters_screen

### Introduction

This screen lists all parameters that can be changed by the user.

For a normal deterministic simulation, you need to enter a nominal value for each parameter. For a probabilistic simulation, you need also to assign probability density functions to the uncertain parameters that you wish to include in the analysis.

### Tool bar Export to Excel See importing and exporting data Import from Excel See importing and exporting data Help Shows this page

### Entering parameter data

Select a parameter in the list to edit its data. A short presentation of the parameter is displayed on the right hand side. Under, in the Data section, a table with the data for the parameter is displayed.

When you click a cell in the table an editor will appear under the table which can assist you in setting a value for the parameter.

#### Data

• Value - This is where the nominal (deterministic) value of the parameter is defined.
• PDF - The probability density function defines the uncertainty distribution. It is recommended that you use the Editor, which is displayed as you click a PDF field, to set probability density functions.
• Unit - The unit serves only as a comment.
• Min value 1) - The minimum value. Is used by some sentitivity analysis methods, and can be used as a parameter for some PDFs (eg. the uniform distribution).
• Max value 1) - The maximum value. Is used by some sentitivity analysis methods, and can be used as a parameter for some PDFs (eg. the uniform distribution).
• Arithmetic Mean 1) - Can be used as a parameter for some PDFs (eg. the normal distribution).
• Arithmetic Std. Dev 1) - Arithmetic standard deviation. Can be used as a parameter for some PDFs (eg. the normal distribution).
• Geometric Mean 1) - Can be used as a parameter for some PDFs (eg. the log normal distribution).
• Geometric Std. Dev. 1) - Geometric standard deviation. Can be used as a parameter for some PDFs (eg. the log normal distribution).
• Median 1) - The 50% percentile.
• Mode 1) - The most likely value. Can be used as a parameter for some PDFs (eg. the triangular distribution).
• N 1) - Number of samples.
• % Lower 1) - The percentage of values below the lower percentile.Can be used for the lognormal distribution.
• % Upper 1) - The percentage of values above the lower percentile. Can be used for the lognormal distribution.
• Lower Percentile 1) - The lower percentile. Can be used for the lognormal distribution.
• Upper Percentile 1) - The upper percentile. Can be used for the lognormal distribution.
• Author 1) - The person who entered the data.
• Reference 1) - The reference for the data of this parameter.
• Comment 1) - A comment regarding the data of this parameter.
• Linked 1) - If this parameter is linked to a simulation result.
• Link 1) - The link between this parameter and a simulation result.

1) - Click the button to display this header.

Below the table are four buttons: Transpose the table (switch rows for columns). Only available for objects with one or more dimensions. Hide default rows/columns. Hide the non-default rows/columns. Show (or hide) more headers. Some headers are originally hidden, such as headers for comments and statistics

#### Editor

The editor appears when you click in a field in the table. When you click a field for a numeric value, an editor which can help you convert values from one unit to another. When you click a PDF the PDF editor appears. You can hide the editor by clicking the Toggle button.

##### Number editor The constants editing tool appears when a table cell is clicked that contains a number. It can be hidden by clicking the Toggle button, as shown in the screen shot below.

The editor contains two tools:

Keypad - Use the keypad with the mouse to enter a value or an operator without having to use the keyboard.

Unit conversion - This tool lets you convert a numerical value from one unit to another (compatible) unit.

• From - The original unit
• Value - The original value
• To - The target unit
• Result - The converted value
• Apply - Copies the results into the selected cell in the table.
##### PDF Editor 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. Lower trunc is often used to avoid negative values for parameters.

See probability density functions for a list of all PDFs.

The PDF Editor has four tools, which are accessed through the buttons next to the Editor button. 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

Delimiters and calculated values from the calculation tool are displayed in the graph using markers. Displays statistics on the currently selected function. 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. 