 marked as minor
Error detected by tests of LogNormalFunctionTest class
Fix error found by tests of class LogNormalFunctionTest.
Comments (6)


 marked as major
In the network attached, the uncertainty for HealthState(Disease=yes,Therapy=no) is modeled by a logNormal with mu=ln(3)=1.09861228867 and sigma=1. Therefore, the value shown in the cell should be exp(mu) = 3, but it is 4.946164.

 attached IDdecidetestsensan.pgmx
Sorry, I forgot to attach the network.

The mean of LogNormal(mu, sigma) is: exp (mu + pow (sigma, 2.0) / 2.0).
Thus, for the introduced values the result is 3.0 x exp(1/2) = 3.0 x 1.6487212707 = 4.9461638121.
A log normal with mean of 3 would be obtained if we also take the logarithm when introducing the value for sigma, i.e. log(1) = 0.

You are right. I made a mistake when reading the Wikipedia. My apologies.
Then my proposal is that, in addition to having a function logNormal, we implement a new function logNormalmv, where "mv" stands for "parametrized with the mean and the variance". This is similar to the difference between the functions Gamma and Gammamv that we already have.
Anyhow, I think we should rethink the idea of having different parametrizations for secondorder probabilities.


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