Problem with getting the difference between two numbers within a group, for all groups in the dataset

[TOM4]

Hello!

Before I will state my problem I will have to apologize for my bad use of English as well as my limited experience with R.

So I have the following problem;
I have a dataset, with two test scores of students in different schools within different municipalities. I want to get the difference between these two test scores for each school in each municipality. As my data has a large number of observations I cannot be asked to do this manually. All help is appreciated!

[nirgrahamuk]

Hi!

To help us help you, could you please prepare a reproducible example (reprex) illustrating your issue? Please have a look at this guide, to see how to create one:

FAQ: How to do a minimal reproducible example ( reprex ) for beginners

A minimal reproducible example consists of the following items: A minimal dataset, necessary to reproduce the issue The minimal runnable code necessary to reproduce the issue, which can be run on the given dataset, and including the necessary information on the used packages. Let's quickly go over each one of these with examples: Minimal Dataset (Sample Data) You need to provide a data frame that is small enough to be (reasonably) pasted on a post, but big enough to reproduce your issue. Let's say, as an example, that you are working with the iris data frame head(iris) #> Sepal.Length Sepal.Width Petal.Length Petal.Width Species #> 1 5.1 3.5 1.4 0.…

[TOM4]

Hello!

Thank you for the advice. I will see what I can do!