Ventana software support forum

Thank you, producing a level with a delayed outflow worked great.

Hello, I have animals that die at several points during the year. At a certain time each year, I need to sum up these deaths from over the previous 365 days in order to estimate how many animals are required to replace them. How do you suggest that I find this number? I am not using the death total ...

Thanks, that should work!

Hello, I have sheep that are move through stages of pregnancy using fixed delays. They enter the breeding pool on a specified breeding date, then after 30 days they are either pregnant if they conceive or are culled if they do not conceive. If the conception rate is below 60%, I would like to not pu...

The Smooth function in Vensim applies a lowpass filter to the data, it doesn't perform time-window averaging. Is there another way?

Hello, I would like to use the average value of a function over a particular time window to get a better picture of my annualized inventories. In other words, lets assume I have widgets being added to a warehouse at a variable daily rate. Each widget stays in the warehouse for exactly 365 days at wh...

Excellent. Thanks!

Hello,

I am currently using a Level with an initial value of 0 to determine the amount of money generated. How can I start integrating the money after 5 days instead of 0 days?

Thank you!

Thank you! Yes, I am going to add stochastic lambing into the model, but am having a hard time figuring out how to best go about it. I can change the "time in late preg" into a RANDOM NORMAL distribution, but this will then take the entire group of Late preg mature ewes out at once. How wo...

Thank you - very helpful! 1 and 2. This breeding dates will be variable and can be from only a few days to 6 months apart. The ewes won't overlap coming into and exiting the two Breeding pools (since all animals in each Breeding pool exit at each breeding date), but they will overlap coming into the...

"date number" is the day of the year (1 to 365) which cycles throughout the run. If I change "date number" and all 5 "breeding dates" to "day" unit, it returns the same errors.

I have an additional question regarding this model. Why do the queues become negative and how would you suggest I control that? I'm guessing it's an integration error?

Thank you!

Yes, exactly. I decided to group them in several stages, then consume a certain amount of feed (DMI) as they move through the stages based on amounts from Excel. I move them through by retrieving the number of animals that have been in the pool the alloted number of days with the QUEUE AGE IN RANGE ...

I'm not trying to initialize the state. I'll be initializing this queue with zero members. My labor costs are proportional to time in queue. Mathematically this would be represented as Labor_cost = sum( widget(tau)*cost_per_widget(tau), tau from 1 to 180 days ) where tau is the time in the queue so ...

Thank you. I can input the data values for each day of the simulation, but how can I do it by day in the queue? In the example model QUEUE functions.mdl, for instance, let's say I have to maintain these items in the warehouse, and the amount of labor required for each item increases as it sits in th...

Hello, I am feeding sheep a different amount each day during pregnancy. I am using QUEUE FIFO ATTRIB (body weight is the attribute) for the sheep and I have a list of the daily intakes for days 1-150 of pregnancy in excel. How do I make the ewes eat the correct amount for each day in the queue? Than...

What is the syntax for taking a partial sum of an array? I would expect something like SUM(array[i!],min_index,max_index) I avoid this kind of for-loop logic as much as possible. If the partial sum is over some predictable subset, use a subrange, e.g. range : a,b,c,d,e,f subrange : a, d, f y = SUM(...

Hello thank you for the fast reply. Question 1: Thank you. That is what I was looking for. Questions 2 & 3: I cannot decipher what you are attempting to do here so this is a guess. I think you need SAMPLE IF TRUE failuretable[Failure] = SAMPLE IF TRUE ( breed >= 0.0001 , failuretable[failure]*fa...

I have a few questions related to number arrays. Question 1. What is the syntax for taking a partial sum of an array? I would expect something like SUM(array[i!],min_index,max_index) I am including my mdl file for the next few questions. Question 2. I want my array to update only when a certain valu...

I have a question about making data arrays and/or arrays of equations. I would like to create an array that can be updated based on data in a model. From the model I find the age of my oldest widget, the recent temperature and humidity from the model and predict the likelihood of failure based on th...

Thank you both for your replies. Re: Administrator I don't have an easy way to extract my model from the larger system, but I'll work on it and get back. Until then maybe my cheese example below is helpful. Re: TomFid Commodities are all the same excepting the value. They all start at the same value...

I have a model that can be represented as a price driven sale of a commodity and I'd like some direction on how to implement it in vensim. I have a queue which represents a commodity, with a single input price and a daily growth in value. I'd like to be able to sell the commodity based on current pr...

Could you explain how to do that?

Thanks!

Hello,

Is there a way to use more than 6 variables in a custom graph? I have groups that flow through 9-10 different stocks that I would like to trace over time on one graph.

Thanks!

I'm trying to import a 2-d array of numerical data from excel using the get excel subscripts function (see attached file). I plan to use a 2-d interpolation of this data set so I'll need to define it as having an XDim and a YDim. Unfortunately I cannot get Vensim to recognize my input command. Any h...