Variable Abs Error Std Dev

Units:	-
Mode:	Input Only
Multi-band:	False
Default Value:	0
Validation Rule:	Any Value
Key Property:	No
Description:	Absolute value of standard deviation of errors
Detail:

Variable Abs Error Std Dev is the input absolute value of standard deviation of errors. In PLEXOS, random errors are generated using the following transformations:

σ * X

and

σ * (e^X - e^0.5)

which follow a normal and a lognormal distribution respectively, where X ~ N(0,1) is the standard normal variable and σ is the Abs Error Std Dev.

Please note that with a lognormal distribution, the standard deviation of the generated errors is σ * √ e² - e¹ , where:

1 / √ e² - e¹  = 0.462706457

So, for example, to get a standard deviation of 5 for the generated errors in lognormal, you will need to enter the value

5 / √ e² - e¹  = 2.313532287

for σ.