The easiest way to communicate this seemed to be to send you the model, which I've attached. If you run it as is, I think it will generate 5 unit errors (when selecting Units Check). Three of these involve LOG or EXP functions, which Vensim insists must have dimensionless units. Here's one example:

Code: Select all

```
Error in units for the following equation:
logHumans =
LOG ( population
+ 1,
10)
logHumans --> people
population --> people
Analysis of units error:
Argument 1 of function LOG must be dimensionless
```

Here's another example:

Code: Select all

```
Error in units for the following equation:
ccH =
c
* pH
* ( 1
- EXP ( d
* Knowledge ) )
* ccE
ccH --> people/gha
c --> people/gha
pH --> Dmnl
d --> Dmnl
Knowledge --> 1/years
ccE --> people/gha
Analysis of units error:
Argument 1 of function EXP must be dimensionless
d
* Knowledge
Has Units: Dimensionless/Year
```

The other type of error has to do with mismatches in the INTEG function for stocks. For example:

Code: Select all

```
Error in units for the following equation:
Knowledge =
INTEG( Learning
- Obsolescence ,
Ko )
Knowledge --> 1/years
Learning --> 1/years
Obsolescence --> 1/years
Ko --> 1/years
Analysis of units error:
Units mismatch in INTEG
Learning
- Obsolescence
Has Units: Dimensionless
Ko
Has Units: Dimensionless/Year
```

Is there some general approach on how to deal with these sorts of unit errors? I find the documentation on Units Check to be pretty sparse.

Thank you!

FYI/BTW the InsightMaker model is here: https://insightmaker.com/insight/14FIlH ... 9/World4-5

An earlier version of Bystroff's model is described in this PLOS paper: https://journals.plos.org/plosone/artic ... ne.0247214