# Important R-functions {#rfunctions}

## Data preparation

We think the following R-functions are useful for checking whether data contains typo or other mistakes:  

`hist`, `table`, `plot`, `boxplot`, `scatter.smooth`


## Figures

There is a lot of online material to learn how to produce nice graphics with R, here some tips by a colleague of us (who does not think it is necessary to mention his name here, but thanks, Steffen!):    

- The [ggplot2-book](https://ggplot2-book.org/) introduces the background of ggplots. It is the reference ot consult for getting an understanding on how ggplot works.

- The [R graph gallery](https://r-graph-gallery.com/) is a user-friendly look-up sheet providing a lot of example code. 

- [This](https://bookdown.org/content/b298e479-b1ab-49fa-b83d-a57c2b034d49/) is the book to the R graph gallery mentioned above. 
 
- And here is another [graphics book](https://r-graphics.org/)