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how to do this

Posted: Sat Feb 03, 2007 4:54 am
by sally
i have a problem.

i want to simulate a product selling condition, so i have a variable" demand", i hope my demand condition is like a "bell shape", but i don't know how to set it? i have try to use ramp or step function , but still can't do it!

hope someone can help me ,

thank you :cool:

Posted: Sat Feb 03, 2007 1:31 pm
by bob@vensim.com
you can certainly use

demand = demand multiplier * exp(-((Time - Peak Demand Time)/Demand Time Spread)^2) ~ Widget/Month
Demand Multiplier = 100 ~ Widget/Month
Peak Demand Time = 50 ~ Month
Demand Time Spread = 25 ~ Month

[Edited on 2007-2-3 by bob@vensim.com]