Rscripts.Rmd

# R scripts

## Create and save a script

* Store commands in a .R/.r script. Create and save a script in RStudio with: 
  + File -> New File -> R Script
  + Once the file has opened: File -> Save 
  + Specify a name: ***the extension .R is automatically added***
  <img src="images/rscript_rstudio.png" width="500"/>

* Execute commands or blocks of commands from RStudio:
<img src="images/rscript_rstudio_cmd.png" width="500"/>

## R syntax

* Case sensitive: **g** is not **G**
* Comment lines start with **#**
* Commands are separated by a **new line** or **;**
```{r, eval=FALSE}
# This is a comment: it will not be interpreted
a <- 10
A + 1
# Will throw an error because A and a are different
```
<img src="images/syntax_error.png" width="500"/>

## RStudio tips in the console

Ctrl + Enter: execute the current line.<br>

<img src="images/arrow_up.png" width="40"/> Upper arrow: goes to the commands previously typed.
Ctrl + cmd + <img src="images/arrow_up.png" width="40"/> : Browse command history.

<img src="images/tab_key.png" width="50"/> Type a letter in the console + "tab": R Studio proposes the different functions or object stored which start with that letter. <br> for example, type **get + "tab"**:

<img src="images/tab_functions.png" width="350"/>