The Metalog Distributions

SPT (Symmetric Percentile Triplet) Metalogs

SPT-metalogs are especially well-suited to decision analysis and other applications where, for example, 10%, 50%, and 90% quantiles are known and a continuous-probability-distribution representation is desired. They use three CDF input data points (m=3) and three terms (n=3).

SPT is the simplest metalog parameterization, and is a special case of the general metalog formulation. For a brief summary of the equations implemented in these workbooks, see the unbounded, semi-bounded, and bounded SPT-metalog equations respectively.  For more detail, see The Metalog Distributions, Section 6.2.1. If you are using metalog distributions for the first time, you may wish to start with an SPT metalog.

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SPT Metalogs
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