Cumulative Plot
To plot a cumulative distribution after a Probabilistic analysis:
- Select Cumulative Plot
on the toolbar or the Statistics menu to open the Cumulative Plot dialog.
- Select the data you want to plot in the Data to Plot (e.g., Factor of Safety or one of the parameters you've defined as a random variable).
- Enter a Number of Bins. The default is 30, but any value between 2 and 100 can be entered.
- Click Plot.
The cumulative distribution is generated in the Cumulative Plot View, and the mean, standard deviation, minimum and maximum values for the data plotted are displayed at the bottom.
A Cumulative Distribution is, mathematically speaking, the integral of the normalized probability density function. Practically speaking, a point on the cumulative distribution gives us the probability that a random variable will be LESS THAN OR EQUAL TO a specified value.
That is, if (X , Y) is a point on the cumulative distribution S-curve, then Y = the probability that the random variable will be <= X.
The data Sampler allows you to obtain the coordinates of points on the S-curve.
The same Data Types which can be plotted on a Histogram can also be plotted as a Cumulative Distribution.
Cumulative plot of safety factor distribution
Right Click Options
A variety of plotting and export options are available in the Cumulative Plot View right-click menu. These include:
- Vertex Markers
- Sampler
- Chart Properties
- Change Plot Data
- Copy
- Copy Data
- Plot in Excel
- Export Image