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title: "Exercises 2"
format: html
---

Please finish Exercises 1 before starting Exercises 2.

E1. Move all your code from exercises 1 E1 to E8 to a single R script file. 
Create a copy of your script.
Clean your code (think about your code style): move packages' loading to the top of the script, improve objects names, use consistent syntax, etc. (hint: read https://style.tidyverse.org/ or try the {styler} package (also https://github.com/Robinlovelace/styler.equals)).
Compare your old and new version -- which one is easier to read?

E2. Create a new RStudio project. 
Add a new folder `R/` inside of the RStudio project and move your new script there.

E3. Create a reproducible example based on your script using the {reprex} package.
(bonus: try to add session information to your *reprex*).
Post the {reprex} output as a new issue at https://github.com/Nowosad/ogh2022/issues.

E4. Use the {renv} package to create reproducible environments for your RStudio project.

E5. Use version control (git) in your RStudio project. 
Create a new repository at https://github.com/, and push your code there.
(hint: you can do it directly from R using the {usethis} package:
1. `usethis::use_git()` to initialize git repository
2. `usethis::create_github_token()` and `gitcreds::gitcreds_set()` to set up GitHub credentials
3. `usethis::use_github()` to push your code to GitHub
)

E6. Change your script to derive three categories of superpixels (instead of six).
Add, commit, and push your changes to GitHub.
(hint: use can you the Git tab in RStudio for that: 
1. Tick the Staged square next to your changed file
2. Click "Commit" 
3. Write a short commit message in the top right corner, and click "Commit" there
4. Click on the "Push" icon
)
Check if your GitHub repository has changed.

E7. Write a new R function called `spat_cluster()` that takes four arguments: an input raster, an output number of categories, a number of superpixels, and a superpixels compactness, and returns a spatial vector object with a specified number of clusters.
In short, this function should combine the code from exercises 1 E7 and E8 
(hint: you can read more about R functions at https://adv-r.hadley.nz/functions.html).

E8. Create a new R package that contains the `spat_cluster()` function.
Push the package to a new GitHub repository.