Ventana software support forum

If I ask today a project manager when the project will be terminated, he estimates the probability (let's assume that this probability is like a normal distribution). If I ask tomorrow the project manager, his estimation will already be slightly changed. So to every time point there is an other probability dense function for all the future.
I modelled this situation that I defined a subscript, say "day". If FINAL TIME of the model is 100 days, then the range of the subscript is (day1-day100). So the probability dense function is a subscripted auxiliary variable, say "probability[day]", and is defined like this:
probability[day] = 0.4*exp(-(day-mean)^2/2)
(this is the equation of the normal distribution for standard deviation = 1 and a time-dependent function "mean").
This runs through, and gives for every subscript i a constant function probability[dayi]. But actually we are only interested in the value of probability[dayi] at a single time point for all i=1,...,100.

Now I would like to see the well known graph of the dense function. For that I define in the Control Panel a new graph with "day" as X-axis and "probability[day]" as Y-axis. Unfortunately this doesn't give what we want to see. How can I tell Vensim that it should take probability[dayi] at dayi?

I'm not sure if I fully understand what your trying to do but these might help.
Attached is a zip file with a model and custom toolset. Open the model and load the custom tools.

The model contains two potential solutions:

1) Using the structure you outlined, you could use the "Bar Graph" tool in the ananysis tools set. Configure this to show values at "select time" and the enter the day you want to display. Alternatively you could set BAR GRAPH 1 to special time and control "special time" time using the control panel. This will display a bar chart of the probabilities at the specified time for all the selected DAY subscripts.

2) You could add a duplicate subscript range, say [iday] where iday = 1,100. Then make the probability a level subcripted by [iday,day].

probabilty 1[iday,day]=
IF THEN ELSE(Time=iday,
0.4*EXP(-(day-mean 1[iday])^2/2),0)/TIME STEP

You can then use the analysis tool BAR CHART 2 to display the PDF, & control the display using subscript selection.

Both solutions are clumsy in vensim and no.2 adds significantly to the model size, but can be made much neater & seamless through a model interface.

Hope the helps in some way if I've understood correctly what you are trying to do.