Random Variables
In order to carry out a Probabilistic Analysis with RocSlope2, you must define at least one input parameter as a random variable.
Input parameters with a probability distribution function icon can be defined as random variables. Users can choose among a list of Statistical Distributions (e.g. Normal, Uniform, etc.) and enter the corresponding statistical properties of the distribution.
- Ensure that the project's Analysis Type is set to Probabilistic Analysis. See the Statistics topic for more information.
- In one of the applicable input dialogs, enter the desired value for the input parameter.
- See the following topics for more information on parameters which can be defined as random variables in a RocSlope2 Probabilistic Analysis:
- See the following topics for more information on parameters which can be defined as random variables in a RocSlope2 Probabilistic Analysis:
- The applicable parameters will have Distribution icons
next to them. Click the icon to open the Statistical Distribution parameters popup.
- Select the desired distribution and enter the required details. Select OK to close the popup.
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In addition, if you are using the Persistence Analysis option, you can define the following random variables:
- Joint Persistence, or
- Trace Length
See the Joint Persistence Analysis topic for more information.
For information about the selection of statistical distributions, standard deviation and minimum/maximum values, see the Statistical Distributions Overview topic.
How Random Variables are Used in the Analysis
Each input parameter defined as a random variable is sampled according to the selected statistical distribution, the Sampling Method and the Number of Samples (chosen in Project Settings). This generates N values of each random variable (where N = Number of Samples).
As shown in the following diagram, each iteration of the Probabilistic Analysis is carried out by loading a new set of random variable samples and re-running the analysis. This is repeated N times where N = Number of Samples.
Random Variable Samples used in Probabilistic Analysis