constant doesn't listen to my min and max limits

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addor
Senior Member
Posts: 50
Joined: Mon Oct 27, 2003 9:45 am

constant doesn't listen to my min and max limits

Post by addor »

I have

now=A*before*(1-before)
before=DELAY FIXED(now, 1 , 0.5)

A is a constant set to 3. In the Synthesim mode I set A to a minimum of 3 and a maximum of 4, a start value of 3.25 and an increment of 1e-010.

If I click to the slider of A, it jumps to 2.82 on the left. Then I pull it to right, and the value runs 3...3.1...3.2...3.25...2.75...2.8..3...3.1...3.2...3.25...2.75...2.8...2.9...3....3.1...3.2....3.25...2.75.... and so on

Why goes it to less as 3, and never to more than 3.25?

Did you once see a similar behaviour? Or is it a user fault?

Thanks and regards,
Peter
bob@vensim.com
Senior Member
Posts: 1107
Joined: Wed Mar 12, 2003 2:46 pm

Post by bob@vensim.com »

It does indeed give odd results. The problem is that an increment of 1e-10 does not make any sense. There are actually only about 100 positions on a slider, Vensim will try to accomodate finer granularities by holding a virtual position (only accessible with the arrow keys) which is good up to abut 1000 positions. The 1e-10 must be causing some sort of overflow.
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