Applies to: @RISK for Excel, all releases

Truncating and Shifting in the Same Distribution

Background:

The reply below uses the following data:

=RiskPearson5(47, 6018, RiskShift(-78), RiskTruncate(11,100))

Truncating and Shifting

@RISK always truncates first and then shifts, regardless of the order of the arguments in the distribution function.

In the example above, after truncating at 11 and 100:

• @RISK shifts the distribution left 78, so that the actual min and max for the Pearson5 are –67 and 22.

This needs to be taken into account when figuring out how to manipulate the function to get the desired result. Subtract the desired shift factor from the desired final limits for the distribution.

 

Details from Example:
If you want a Pearson5 that is truncated at 11 and 100 after shifting left by 78 units, compute the pre-shift truncation limits as:

• Lower limit: 11 – (–78) = 89

• Upper limit: 100 – (–78) = 178

Then code your function like this:

=RiskPearson5(47, 6018, RiskShift(-78), RiskTruncate(89,178))

The truncation limits 89 to 178 before shifting become your desired limits 11 to 100 after shifting.

 

 

 

Related Articles:

Shift Factor in a Distribution

Cutting Off a Distribution at Left or Right