Search found 36 matches
- Wed Apr 24, 2019 3:40 pm
- Forum: Vensim
- Topic: accumulate auxillary values
- Replies: 4
- Views: 2316
Re: accumulate auxillary values
Thank you, producing a level with a delayed outflow worked great.
- Wed Apr 24, 2019 3:10 pm
- Forum: Vensim
- Topic: accumulate auxillary values
- Replies: 4
- Views: 2316
accumulate auxillary values
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 ...
- Mon Nov 20, 2017 3:54 pm
- Forum: Vensim
- Topic: If then else with fixed delay
- Replies: 2
- Views: 1673
Re: If then else with fixed delay
Thanks, that should work!
- Mon Nov 20, 2017 2:52 pm
- Forum: Vensim
- Topic: If then else with fixed delay
- Replies: 2
- Views: 1673
If then else with fixed delay
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...
- Wed Sep 20, 2017 5:14 pm
- Forum: Vensim
- Topic: average value over time window
- Replies: 3
- Views: 2026
Re: average value over time window
The Smooth function in Vensim applies a lowpass filter to the data, it doesn't perform time-window averaging. Is there another way?
- Wed Sep 20, 2017 3:05 pm
- Forum: Vensim
- Topic: average value over time window
- Replies: 3
- Views: 2026
average value over time window
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...
- Sun Jan 01, 2017 2:40 pm
- Forum: Vensim
- Topic: cumulative value over specified time range
- Replies: 2
- Views: 1911
Re: cumulative value over specified time range
Excellent. Thanks!
- Fri Dec 30, 2016 11:42 am
- Forum: Vensim
- Topic: cumulative value over specified time range
- Replies: 2
- Views: 1911
cumulative value over specified time range
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!
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!
- Mon Sep 19, 2016 2:28 pm
- Forum: Vensim
- Topic: capture daily values from excel
- Replies: 18
- Views: 8978
Re: capture daily values from excel
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...
- Thu Sep 15, 2016 5:39 pm
- Forum: Vensim
- Topic: capture daily values from excel
- Replies: 18
- Views: 8978
Re: capture daily values from excel
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...
- Thu Sep 15, 2016 2:35 pm
- Forum: Vensim
- Topic: capture daily values from excel
- Replies: 18
- Views: 8978
Re: capture daily values from excel
"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.
- Thu Sep 15, 2016 2:28 pm
- Forum: Vensim
- Topic: capture daily values from excel
- Replies: 18
- Views: 8978
Re: capture daily values from excel
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!
Thank you!
- Thu Sep 15, 2016 1:50 pm
- Forum: Vensim
- Topic: capture daily values from excel
- Replies: 18
- Views: 8978
Re: capture daily values from excel
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 ...
- Sat Sep 10, 2016 3:55 pm
- Forum: Vensim
- Topic: capture daily values from excel
- Replies: 18
- Views: 8978
Re: capture daily values from excel
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 ...
- Sat Sep 10, 2016 1:21 pm
- Forum: Vensim
- Topic: capture daily values from excel
- Replies: 18
- Views: 8978
Re: capture daily values from excel
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...
- Fri Sep 09, 2016 10:40 am
- Forum: Vensim
- Topic: capture daily values from excel
- Replies: 18
- Views: 8978
capture daily values from excel
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...
- Thu Aug 18, 2016 3:47 pm
- Forum: Vensim
- Topic: question about sum and arrays
- Replies: 7
- Views: 3675
Re: question about sum and arrays
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(...
- Thu Aug 18, 2016 3:40 pm
- Forum: Vensim
- Topic: question about sum and arrays
- Replies: 7
- Views: 3675
Re: question about sum and arrays
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...
- Thu Aug 18, 2016 2:43 pm
- Forum: Vensim
- Topic: question about sum and arrays
- Replies: 7
- Views: 3675
question about sum and arrays
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...
- Fri Aug 12, 2016 3:16 pm
- Forum: Vensim
- Topic: creating an array of functions
- Replies: 1
- Views: 1529
creating an array of functions
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...
- Wed Oct 28, 2015 1:13 am
- Forum: Vensim
- Topic: Price threshold based sale decisions
- Replies: 6
- Views: 3799
Re: Price threshold based sale decisions
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...
- Tue Oct 27, 2015 1:20 am
- Forum: Vensim
- Topic: Price threshold based sale decisions
- Replies: 6
- Views: 3799
Price threshold based sale decisions
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...
- Thu Apr 09, 2015 2:14 pm
- Forum: Vensim
- Topic: more than 6 variables in custom graph
- Replies: 3
- Views: 2341
Re: more than 6 variables in custom graph
Could you explain how to do that?
Thanks!
Thanks!
- Wed Apr 08, 2015 10:12 pm
- Forum: Vensim
- Topic: more than 6 variables in custom graph
- Replies: 3
- Views: 2341
more than 6 variables in custom graph
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!
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!
- Tue Apr 07, 2015 1:29 am
- Forum: Vensim
- Topic: 2-dimensional array import from Excel
- Replies: 1
- Views: 1700
2-dimensional array import from Excel
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...