mooc-rr/module2/exo4/exercice_R_en.org
2019-03-27 12:31:45 +01:00

3.2 KiB

Your title

Some explanations

This is an org-mode document with code examples in R. Once opened in Emacs, this document can easily be exported to HTML, PDF, and Office formats. For more information on org-mode, see https://orgmode.org/guide/.

When you type the shortcut C-c C-e h o, this document will be exported as HTML. All the code in it will be re-executed, and the results will be retrieved and included into the exported document. If you do not want to re-execute all code each time, you can delete the # and the space before #+PROPERTY: in the header of this document.

Like we showed in the video, R code is included as follows (and is exxecuted by typing C-c C-c):

print("Hello world!")
[1] "Hello world!"

And now the same but in an R session. This is the most frequent situation, because R is really an interactive language. With a session, R's state, i.e. the values of all the variables, remains persistent from one code block to the next. The code is still executed using C-c C-c.

summary(cars)
     speed           dist       
 Min.   : 4.0   Min.   :  2.00  
 1st Qu.:12.0   1st Qu.: 26.00  
 Median :15.0   Median : 36.00  
 Mean   :15.4   Mean   : 42.98  
 3rd Qu.:19.0   3rd Qu.: 56.00  
 Max.   :25.0   Max.   :120.00

Finally, an example for graphical output:

/polarolouis/mooc-rr/media/commit/912e8519b4ceea57c06040abe55b15b4e80fc3b4/module2/exo4/cars.png

Note the parameter :exports results, which indicates that the code will not appear in the exported document. We recommend that in the context of this MOOC, you always leave this parameter setting as :exports both, because we want your analyses to be perfectly transparent and reproducible.

Watch out: the figure generated by the code block is not stored in the org document. It's a plain file, here named cars.png. You have to commit it explicitly if you want your analysis to be legible and understandable on GitLab.

Finally, don't forget that we provide in the resource section of this MOOC a configuration with a few keyboard shortcuts that allow you to quickly create code blocks in R by typing <r or <R followed by Tab.

Now it's your turn! You can delete all this information and replace it by your computational document.