Ventana software support forum

I have a problem with the delay:

DELAY FIXED((0.4*input), 20, (0.1*input))

The Type is Level and the input rises every year.
After the run of a simulation the output is rising after 20 years, but not before the 20 years. But I want that it rises all the time.
Do you have a solution for my problem!?
Thanks a lot for your help!

The problem is that the DELAY functions initialize the internal state of the delay (which is basically a chain of a bunch of levels) to a constant rather than some presumed historical profile of the inflow. One solution would be to create an explicit chain of levels, which you could then initialize as needed. Another option - probably easier - would be to override the output of the delay for the first 20 years of your simulation. For example:

output = IF THEN ELSE( time-INITIAL TIME < delayDuration, historic input, dynamic delay)
historic input = (whatever you think the profile should be)
dynamic delay = DELAY FIXED( input, delayDuration, initVal )

initVal could be whatever you want, since the IF in the output equation will override it anyway.

Tom

You can also use DELAY CONVEYOR which allows you to specify the time profile of the initial contents of the delay using a Lookup function.

Of course the simplest solution is

output = INTEG((input - output)/smooth time,input)

but this is a first order not a fixed delay.

Thanks a lot for your solution!

Steven