Strength-Stress Interaction Calculation Parameters
The following table describes the parameters for strength-stress interaction calculations. For more information, see Performing a Strength-Stress Interaction Calculation. These parameters are in addition to those for specifying the distribution and scale, slope, and possibly threshold t0 or Gamma (γ) value for each variable. The supported distributions are listed along with their input values in the table in Models Per Distribution.
Parameter
Description
Factor
The percentage by which to multiply the variable in question when performing the calculation. The default is 1 so that no change is made. To perform what-if analysis, you enter a percentage value for the distribution to facilitate simple distribution changes or extensions. For example, if the usage distribution specified is for one year and you want to obtain the result for two years of usage, then you enter a 2. To perform more complicated what-if analyses, you change individual distribution parameters as needed.
Range
The range of the distribution from which to randomly select data points. Choices are:
Full. When selected (default), data points are selected from all portions of the distribution.
Lower. When selected, data points are selected from the lower X percent tail of the distribution. So that you can enter the percentage value, % becomes available. The default is 10, which means data points are selected from the lower 10 percent tail of the distribution.
Middle. When selected, data points are selected from the middle of the distribution. So that you enter the percentage of both tails that are to truncate, % becomes available. The default is 10, which means data points are selected from the middle 80 percent of the distribution, with each tail being truncated 10 percent.
Upper. When selected, data points are selected from the upper X percent tail of the distribution. So that you enter the percentage value, % becomes available. The default is 10, which means data points are selected form the upper 10 percent tail of the distribution.
For more information, see Random Point Sampling.