I would very much appreciate any help I can get for the following. I have an excel spreadsheet that contains projections of precipitation. The sheet has two columns (day and precipitation) and there are over 20,000 rows, i.e. over 20,000 days of precipitation. I loaded this sheet onto AnyLogic. I am using a system dynamics model and have a dynamic variable called Rainfall. For each day of the simulation I want Rainfall to pull the value from the loaded database, but don't know how to link the dynamic variable to the database. I have already tried the following: inserting a tableFunction named ProjectedRainfall and its values are "loaded from database." For "argument column" I chose "day" and for "value column" I chose precipitation. I then inserted a function named getrainfall and under function body I wrote "return ProjectedRainfall(time()). I then added a dynamic variable that is set to equal "getrainfall(time())". This generates an error that states "The method getrainfall() in the Type Main is not applicable for the arguments (double)." Any ideas on what I may be doing wrong or alternatives to how I could go about linking the dynamic variable to the database? Thank you for the help!
2 Answers
No need to go via a table function. you can pull data directly from your table using SQL.
Learn to use the Database query wizard. Put your cursor into a code field and open it as below. It allows you to select any data and even writes the correct code for you:
There are lots of example models and help articles on this, hope this helps to get you going
Although it is possible to directly lookup your data from the Database when you need it, this is not advised if this will be happening multiple times during your model execution, which appears to be the case in your model.
Your best option when working with the database is to get the data from the database only once and then put the data in either the agents you created or in new Java classes.
See the SO answer here for more details What is the fastest way to look up continuous data on Anylogic (Java, SQL)
Thus putting al the data in a tableFunction is a good way to prevent the costly exercise of accessing the database.
I replicated your situation and it appears to be working
Here is the table with some dummy data
Here is the setup of the table function
Here is the setup of the dynamic variable - See that I have added an argument in the dynamic variable so that it can be used in the default value
Here is the table function when running the model
And here is some text that uses the dynamic variable to display the precipitation for the current day. You could also simply directly access the table function here, no need to go via the dynamic variable. Although I assume you need the dynamic variable for your system dynamics model
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