I am simulating the process of an emergency room. I have a problem with patient arrivals.
I have the total number of annual patients, and the probability of distribution of arrivals over the different months and days of the week. For example: total number of arrivals 120000, which divided by the 52 weeks that make up a year is about 2308 per week and therefore 329 per day. However, if we are in May, I know that there are a few more arrivals, so I have to multiply the weekly arrivals by 1.05 and therefore 2423 per month.
Can I set up this reasoning through schedules?
The Source object has an option to create agents based on a database datable. Furthermore, it doesn't have to be a record per arrival but several arrivals at the same time. See here for more details.
Related
My arrival rate for my source is in hours, and I am using events to set it's rate to a distribution at different times, sourceShoppers.set_rate(triangular(1, 5, 2));. However, the source is producing roughly 3 per second, as opposed to an average of 2 an hour.
do this:
self.set_rate(triangular(1,5,2), PER_HOUR);
Nevertheless, when you do that, notice that you will get a random sample for the triangular distribution, which will set the rate to be for instance 1.2 per hour in which case the arrivals will follow a poisson distribution with an average of 1.2 per hour always unless you change the rate again...
If you want some advice, you have to say what you want to achieve...
I am working on a system dynamics model, whose units are days, in AnyLogic. The model tracks daily demand of water for 10,950 days (30 years). One of the model’s outputs is a timeplot that keeps track of this demand, but I don’t want it to plot the daily demand. Instead, I want the timeplot to show demand in years (i.e. the sum of 365 days across the 30 years). I am having a bit of trouble finding a way to do this and would appreciate any help. Thank you!
I assume your problem is twofold.
How to get the time plot to display 30 years of data
How to sum the annual demand for 30 years
Here is a simple example that I believe answers your question.
In this simple model, there is a daily event that simulates the daily demand, and adds it to a variable called annualDemand
There is another event that runs yearly and tasks the annualDemand and saves it to a data set, and rests the annual demand accumulator to 0.
In your time plot, you simply display the dataset which will at the end of the model only contain 30 entries, one for each year.
By following the same principles
Save annual demand
yearly event to add annual demand to data set and reset the annual demand
time plot to plot the dataset
You should be able to get what you need.
I need to simulate a simple M/M/1 problem in Anylogic. So far, I created the model and calculated all performance measures like the average time in queue and system and the average number in queue and system. Now I need to calculate the Total Costs. The painting time for a car would be 6 hours and costs $70 per hour. The cost of idle time per car is $100 per hour. The cars arrive according to a Poisson process with a mean rate of 1 every 5 hours. Can someone help me how I can calculate the total costs in this model in annylogic?
enter image description here
Refer to this question about measuring time:
Method the measure the time an agent is not in use during a simulation
You need to create an agent type that has variables for time and cost. Then on the On Enter and On Exit fields, record time and cost for individual agents. Once you have measured time, cost is simply time multiplied by the hourly cost.
If you want to measure total cost, you can create variables in main such as totalCost and the code of the sink's On Enter would be:
totalCost += agent.totalCost
Where the second totalCost variable would be the variable inside the agent type.
Anyway, the above should give you a good idea on how to proceed...
Anybody has a reference for how AnyLogic implements it's rate per day? Specifically, my agent is at different locations (based on time of day) throughout the day. If there are 10 triggers a day, do they happen randomly for each agent throughout the day, or only at the beginning of a day (when agent is at home), etc.?
Thank you, Amy! Your explanation was very helpful.
The rate follows the Poisson distribution. If you divide 1/rate, you will get an inter-arrival time that follows the exponential.
As this is random, you may not actually get 10 a day - you may get 9 one day and 11 the next. If you want to get exactly 10 in a day, you need to think about writing your own code to make that happen. That might be something like generating 10 dynamic events randomly sampled times that all trigger a transition in their action code (that would not be exponential between events).
I'm in healthcare and we're trying to assess the number of discharges we have per hour of day, but we'd also like to be able to filter them down by day of week, or specific month, or even a particular day of week in a particular month (e.g. " what is the average number of discharges per hour on Mondays in January?")
I'm confident that Tableau can do this, but haven't been able to make the averages show up in my line graph... every time that I convert it from COUNT to AVG, the line simply goes straight. I got close when I did a table calculation to find the Average (dividing the count per hour by the number of days captured in the report), but when I add a filter for either the month or day of week, selecting one of the options of the filter reduces the total number that is being counted, rather than re-averaging the non-filtered items. (i.e. if the average of the 7 days of the week is "10" for a particular hour, and I deselect the first three days of the week, it's now saying that my average for that hour is roughly 6, despite the fact that all of the days are very close to 10 at that hour.)
Currently, my data table has the following columns:
Account#/MonthYear/HourOfDay/DayOfWeek
ex.12345678/ Jan-17 / 12 /Sunday
I would just create a few calculated fields to differentiate the parts of the calendar you might want to filter/aggregate on. Mixing the month and day of the week with filtering is pretty straight forward with the calculated fields. Then do standard summing to get what you are looking for because an average count of records is always one unless you are throwing some other calculation into the mix. I threw a quick example up on Tableau Public for you to get the idea.