Vensim model formatting

hebeil · Post by **hebeil** » Mon Sep 03, 2007 4:02 pm

Hello,
I'm new to Vensim and was wondering if anyone had tips on general formatting issues. For instance, in trying to connect one rate to another, I can't seem to move the name of the rate without moving the whole thing. Also, if I want to have 2 flows coming out of 1 stock, can I have both coming out of the side or does one need to be out of the side and one from the top or bottom? I attached an example model that has the problems I'm referring to. Any help is much appreciated!

Thanks!
Heather

Monte · Post by **Monte** » Mon Sep 03, 2007 4:16 pm

Hi Heather,

Yes, you can have both flows coming from the same side of a stock. Just click the rate sketch tool, then click the stock in the drawing area and move the mouse in the same direction of the first flow.

MK

LAUJJL · Post by **LAUJJL** » Tue Sep 04, 2007 9:45 am

Hi

I would not make a rate depend from another rate, for clarity reasons.
I would prefer define one or some intermediate auxiliaries and make the different rates depend on the auxiliaries.
In my models, the only action of the rates is to feed or decrease stocks, they do not have an influence on anything else.
But the administrators know if it is a good practice to make a rate depend from another one.
Regards.
JJ

bob@vensim.com · Post by **bob@vensim.com** » Tue Sep 04, 2007 11:19 am

For clarity rates are named directly so that moving the valve also moves the name of the rate. You can also use an unnamed rate (create a rate then press the Esc key instead of filling in the name) and connect other variables to that.

Connecting a rate to another rate is, as JJ has stated, done only very rarely. The gravity model in the samples show this, but beyond physical acceleration and velocity I have never made use of a rate connected to a rate.

As far as multiple rates coming out - this is whatever you want. Running two in parallel is common and often done by putting attaching the name of the rate on the top flow to the top of the valve (right click on the valve).

LAUJJL · Post by **LAUJJL** » Tue Sep 04, 2007 12:13 pm

Hi

There are several examples in the molecule where rates are influencing other rates or eventually auxiliaries.
But they can eventually be written differently to make them clearer:
Molecules: traditional cascaded coflow, Hines cascaded coflow, backlogshippingprotectedbylevel.
Regards.
JJ