Last month, @freakonometrics posted a bunch of articles on his blog about the North pole (in French):
There are some maps on these articles that were produced using ggplot2 excellent package in R. We want to share our code here.
Après avoir présenté rapidement la régression linéaire multiple avec R, et parlé un peu des problèmes de multicolinéarité, on va se pencher sur différentes techniques qu’il est possible d’employer pour sélectionner un modèle. Bien sûr, il en existe beaucoup d’autres. Le but est ici de donner un rapide aperçu.
Suite au premier exercice sur la régression linéaire simple avec R, voici un nouvel exercice sur la régression linéaire multiple avec R.
À nouveau, je vais dans un premier temps présenter toutes les étapes comme on pourrait les faire à la main, puis je terminerai par les deux lignes de code qui permettent d’obtenir les mêmes résultats.
We sometimes need the distance between two countries in econometric models, for instance in gravity models. Bur for some countries, I think this measure could cause problem. Let’s take an example. If we want to model the volume of trade between country (i) and country (j), the economic theory says it will depend on the distance between (i) and (j). Let (i) be China, (j_1) Japan, and (j_2) India. The distance between (i) and (j_1) will be lower than between (i) and (j_2). Can we consider, though, that Japan is farther from China than India is?
So, rather than compute the distance between two head cities, it might be more accurate to compute the closest distance between the borders. If a border is shared by country (i) and country (j), then the distance should be zero.
Basketball court with ggplot2.
Following freakonometrics‘ tweet on basketball and big data, linking to this really cool javascript animation, as seen on @kirkgoldsberry‘s article on Grantland, I have spent some time drawing a basketball court in R. I have tried to be the most accurate possible, using this layout.
Il m’arrive souvent de fouiller dans mes fichiers pour tenter de retrouver un code R pour produire un graphique, ou manipuler des formats (comme par exemple des dates). Un moyen rapide de retrouver les informations serait de publier mes code sur ce blog. Il est même possible que certaines personnes puissent y trouver un léger intérêt. C’est pourquoi je souhaite commencer une série d’articles intitulés « Pense-bête R », qui sera alimentée à chaque fois que je rencontrerai un cas de figure sous R que je risque de rencontrer à nouveau.
To begin this new year, I had the pleasure to have some fun with R, Gephi and Twitter.
In this post, I will present a way to plot a European Union map using R. As you know, some countries are missing in the maps package. So, instead of working with that package, we will use the rworldmap one, available on CRAN. We will also need two more packages : ggplot2 and grid.
After some research on the Internet, I gave up trying to find an R function to add a scale bar and a North arrow on a map, using ggplot().
So, I would like to present you what I have come up with.
The idea is really basic : we create two polygons for the scale bar, we add some text above, and we draw an arrow. That’s it. The only tricky thing here, is the way to obtain the coordinates of each element. An easy solution is to use the gcDestination function, from the maptools package.
It seems that everything is possible with R. My latest discovery is that you can easily send emails from the R console. It can be very useful for sending reporting files directlyRead More…
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