Modifying Distributions

After a distribution has been drawn, @RISK will convert the drawn curve into a graph using a set number of points on X,Y coordinates, represented as dots on the graph, that match the freeform curve. The number of points (or bars in the case of Histograms and Discrete Probabilities), and hence the detail of the resulting graph, is set in the Distribution Artist Options window. Additionally, when the mouse button is released to complete drawing, @RISK will automatically plot the endpoints of the graph at the minimum and maximum values that were set in the Distribution Artist Options window.

Right-click on the graph to open a contextual menu (Figure 1, below) with the following options:

Figure 1 - Right-click on graph

  • Undo Drag - This will only be available after a change has been made to the graph. Undo the last change made. Only the last change is available to undo!
  • Add Point/Add Bar- Add another point or bar to the graph.
  • Remove Point - Right-click on an existing point and select to remove it from the graph.
  • Draw New Curve - Open the Distribution Artist Options window to start a new graph.
  • Fit Curve - For Probability Density (General) and Cumulative Ascending graphs only. Open the Fit Distributions to Data window to start a new fitting process for the data represented in the graph.
  • Copy Graph - Copy the current graph to the clipboard as a bitmap image.
  • Copy Data - Copy the X,Y coordinates of the graph to the clipboard as delimited text.

In addition to using the right-click menu, once a curve has been drawn it can be modified in other ways, detailed below.

Editing Points

Individual points or bars on the graph can be moved, within some limitations.

To reshape a graph, move the mouse over the point (or the top of the bar for histograms and discrete probabilities); when the cursor becomes a four-way arrow, click-and-hold and drag to move. The following limitations apply:

Graph Type Move Coordinates Notes
X-Axis Y-Axis
Probability Density (General) Yes Yes Point cannot move beyond adjoining points on X-Axis
Probability Density (Histogram) Yes No Bar can only move along Y-Axis
Cumulative Ascending Yes Yes Moving point on Y-axis will affect adjoining points
Cumulative Descending Yes Yes Moving point on Y-axis will affect adjoining points
Discrete Probability Yes Yes Bars can be moved on both X-Axis and Y-Axis

Minimum and Maximum Values

The minimum and maximum values for the distribution are represented on the graph by dotted lines. The curve of the graph cannot be drawn outside these delimiters, and no point or bar can be moved beyond them.

To change the minimum and/or maximum values of the distribution, hover the mouse over the line to be moved and click-and-drag to reposition.

Do not use the 'Draw New Curve' button to edit an existing curve! Using this dialog will clear the existing graph so that a new one can be drawn!