Select Distribution

Introduction

Use the Select distribution window to insert a randomly sampled value, a distribution object or a percentile calculation from any of the univariate distributions in the spreadsheet.

The Select Distribution window lets you choose between different categories of distributions. From the list on the left, you can choose to see all available univariate distributions, or those of one of the following categories:

Click a distribution to select it (hold CTRL while clicking or drag the mouse for selecting more than one distribution) and then press the OK button.

Once the distribution(s) of choice selected, you are taken to the Distribution Details window, where you can specify the distribution parameters, change the percentiles, export a sampled random value to a spreadsheet cell, etc...

Also, dynamically updating PDF, PMF and/or CDF graphs and useful summary statistics are shown.

To list the univariate distributions you can insert with this window, click here.

Window elements

Toolbar

From left to right, the toolbar buttons allow you to:

• Show/hide the PDF or PMF

• Show/hide the CDF

• Show/hide the panel on the left with the parameters of the selected distribution(s)

• Show/hide the panel on the right with the statistics of the selected distribution(s)

• When multiple distributions are loaded, show the graphs of all loaded distributions combined, or only the graph of the selected distribution.

• Insert the selected distribution into spreadsheet cell(s). You can insert the distribution as an object, a sampled value from it, or a value corresponding to a U-parameter on [0,1]

• Help on this window (this brings you to this current MA page)

For each loaded distribution, a parameters panel is shown on the left.

• The distribution's name. This has a pink background if the distribution is currently selected, and a white background if not.

• Buttons for: help on this distribution, replace by a new distribution, minimize/expand the parameters, delete distribution from the list.

• The distribution's parameters and their values. These values that occur in the distribution's PDF and CDF and typically define its scale,location, and shape. You can change these manually or link them to a spreadsheet cell.

• The distributions boundary and shift values. For unbounded distributions, this will show - or + Infinity as default boundary values. The shift determines how many units the distribution is shifted along the X-axis (default is 0). Press the buttons to specify boundary points in X-values or percentile values.

For explanations about other fields, buttons, graphs and summary statistics tables in this window, see

Useful tips and tricks

The output of ModelRisk windows always corresponds to VoseFunctions (the functions ModelRisk adds to Excel) being entered into one or more spreadsheet cells.

You can always re-open the window for a ModelRisk function that is in a spreadsheet cell by using View Function. Select the spreadsheet cell and then select View Function from the ModelRisk menu/toolbar/ribbon.