PsiTruncate ([min], [max], [type])
PsiTruncate is used to restrict the values of samples from an uncertain variable’s distribution or a PSI Statistic function to lie within the range from min to max. Supported PsiStatistics functions are: PsiKurtosis, PsiMax, PsiMean, PsiMedian, PsiMin, PsiMode, PsiPercentile, PsiPercentileD, PsiRange, PsiSkewness, PsiStdDev, PsiTarget, PsiTargetD and PsiVariance.
This property accepts "empty" arguments for both the min and max parameters. If not provided, the default of -1E+30 will be used for min and the default of 1E+30 will be used for max.
A third optional argument, type, was added in V2019. If a 1 is passed (default), the bounds will be interpreted as numbers. If a 2 is passed, the bounds will be interpreted as standard deviations. If a 3 is passed, the bounds will be interpreted as percentiles, which must be between 0 and 1.
Example:
You can create lower and upper bounds of 96 and 104, respectively, for the PsiNormal distribution given the parameters mean = 100 and standard deviation = 2 in one of three ways:
When type = 1 (values), use: =PsiNormal(100,2, PsiTruncate(95, 105, 1))
When type =2 (std. dev.), use =PsiNormal(100,2, PsiTruncate(-2, 2, 2))
When type = 3 (percentiles), use =PsiNormal(100,2,PsiTruncate(0.03, 0.97, 3))
The same can be done to a supported Psi Statistic function.
If A1 = PsiNormal(0,1)
When type = 1 (values), use: =PsiMean(A1,,,, PsiTruncate(95, 105, 1))
When type =2 (std. dev.), use =PsiMean(A1,,,,PsiTruncate(-2, 2, 2))
When type = 3 (percentiles), use =PsiMean(A1,,,,PsiTruncate(0.03, 0.97, 3))