Cumulative Plot
To plot a Cumulative Distribution after a Probabilistic Analysis:
- Select Plot Cumulative
from the toolbar or the Statistics menu. - Select a Data Type.
- When it is relevant, select a Location:
- Single Segment: Select the specific segment you would like to plot from the drop-down menu.
- Multiple Segments: Select the segment(s) you would like to plot. Click Pick Segments and right-click and drag the mouse to select the segments you are interested in. Press ENTER.
- End Wedges: Select the wedge you would like to plot from the drop-down menu.
- Enter a Number of Intervals. The default is 30, but any value between 1 and 500 can be entered.
- The display of interval markers may be toggled on or off with the Attach Markers to Distribution checkbox.
- Select OK.
The Cumulative Distribution will be generated, and the mean, standard deviation, minimum and maximum values for the data plotted, will be listed at the bottom of the plot.
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 the user to obtain the coordinates of points on the S-curve.
The same Data Types which can be plotted with Plot Histogram can also be plotted as Cumulative Distributions. See the Data Type topic for details.
Right-click Options
The following options are available in the right-click menu for Cumulative Distributions: