Operations Research Models and Methods / Computation

Random Variables

Plotting Distributions


The Plot_RV command is found on the OR_MS menu and makes a numerical presentation of the distribution of one or more random variables and a chart showing the selected distributions. On selecting this command the dialog box below appears.

Up to three distributions may be selected, with either the density function or cumulative specified. The lower and upper limits of the range and the step size determine the detail of the presentation. Clicking on the Make Integer Histogram box, will assure that each cell represents an integer value. The cell designation identifies where the information will be shown on the worksheet. Before selecting the Plot Distribution item, put the cursor on the upper left corner of the region where the plot is to appear.

The dialog results in the display below which shows both the probability and cumulative distributions for the triangular distribution defined for the dice throw. The Chart check box determines whether a graphical chart is constructed. If it is not selected, only a tabular presentation of the distributions appear as shown on the left of the figure below. The Chart Type selection specifies either a line or column chart. The former is more appropriate for continuous distributions, the latter for discrete.

Operations Research Models and Methods
by Paul A. Jensen and Jon Bard, University of Texas, Copyright by the Authors