SHIFT IF TRUE

Stef · Post by **Stef** » Tue Oct 30, 2007 9:00 am

Hi,

I just started to work with VENSIM to run a certain model - so I'm not very experienced so far. Nevertheless to understand the model I need to understand the SHIFT IF TRUE-function.

I read the example to this function in the "Vensim Reference Manual" on page 118 but that does not really help me as I have many questions, e.g.:
- is it the example's aim to count the population or to sum the ages of the individuals belong:(ing to the population?
- what is meant by "rightmost subscript of var"?
- what does "ageh" mean?
- does "inval" mean "invalid"?

Thanks for your help!!

Regards,
Stef

bob@vensim.com · Post by **bob@vensim.com** » Tue Oct 30, 2007 11:05 am

Think of a subscript as a bucket - there are 66 buckets in the example - imagine them all in 1 roww. The SHIFT IF TRUE function causes the contents of each bucket to be shifted to the next bucket in the line.

The rightmost subscript corresponds to the last bucket in the line. All of the other things you mention are defined as part of the example.