Ideograph – explore ideologies of political parties with SPAQRL requests to WikiData, D3 and PixiJS.

Ideograph is a visual tool for exploring ideologies of political parties. It queries its data directly from the frequently updated WikiData graph database. You can filter the graph by country, and find further information by clicking on the node labels.

Ideograph is licensed under GNU GPL 3.0.

ideograph

Where does the data come from?

WikiData is an RDF triple store holding a growing […] Continue Reading…

Unify the extent of rasters in QGIS 3 to avoid clipping by raster calculator

This one drove me crazy today! If you try to sum values from rasters with different extent, the raster calcultor clips the result to their overlapping zone. This might make sense in most cases, but in many other cases it absolutely does not. Users should have a choice.

An old workaround (2013) is proposed on a page called Raster extent […] Continue Reading…

Premiers pas avec le module R “Quanteda” pour l’analyse linguistique

Cet exercice a pour but de vous familiariser avec le module Quanteda pour l’analyse linguistique. Il présuppose que vous avez fait les premiers pas avec R et Rstudio.

Installez et activez les modules

Installez les modules quanteda, quanteda.textstats, quanteda.textplots, readtext, ggplot2 et udpipe:

Créez un nouveau script R pour sauvegarder la progression de votre travail. Ajoutez les lignes suivantes à votre […] Continue Reading…

Reorder geom_bar or anything else in ggplot by the value of your choosing

You still find recent answers on StackOverflow counseling to redefine the factors of a data.frame to reorder elements of a ggplot graphic. In the 2020’s, this can be avoided. Factors are a heritage of a numerical focus of R, when text values were seen as an anomaly or, at best, as ordinal values. I highly recommend leaving the […] Continue Reading…

Scrape an image from DeepZoom with R and magick, recomposing a single image from multiple tiles

DeepZoom allows webmasters to display high resolution images in an online viewer. Among its users:

The British LibraryThe World Digital Library (WDL)Polona, the Polish Digital National LibraryBALaT, Belgian Art Links and Toolsand many others

DeepZoom mostly discourages downlading the original high resolution images to your local drive. This is how to get these images nevertheless with the help of R.

Examining […] Continue Reading…

Les encarts dans QGIS

Pour qu’un personne ne connaissant pas la région que vous cartographiez puisse mieux s’orienter, il vaut la peine d’utiliser un encart,  ce qui est possible dans le “print composer”. Il suffit, pour cela, d’ajouter deux cartes différentes.

Lors de la création d’encarts, il est souvent pertinent de changer d’implantation. Pour identifier les bâtiments à l’échelle locale, par exemple, utilisez des […] Continue Reading…

Radar charts with R

Radar charts, also called spider charts, serve to compare profiles of individuals. They are most useful if every profile is compared to an average profile. They are most pertinent when the order of the axis has an inherent sense, such as cardinal directions, the surroundings of an individual (the level of noise from left, right, front, aft), antagonistic […] Continue Reading…

Workshop Poliphilo 2: seconde partie

Ceci est la seconde édition du workshop créé par l’auteur pour le laboratoire d’architecture ALICE (EPFL-ENAC) dans le cadre du projet de recherche et d’enseignement POLIPHILO. Le premier workshop (2019) demeure disponible en ligne. Si vous n’avez pas assisté à la séance du 1e avril, consultez la première partie du deuxième workshop.

Dans cette seconde partie, nous allons nous […] Continue Reading…

Mediatized Places in Wuhan – a Cartographic Attempt banned by Facebook

We’ve heared a lot about Wuhan (武汉), during 2020, for obvious reasons. Facts have a hard life on the battlefield of speculations, caught up in crossfire between pro-Trump propaganda channels (FoxNews, OANN, …) and Chinese state media. Scientists propose two hypotheses for the origin of the Covid-19:

A zoonotic transmission from animal to human, traced back to the Huanan sea […] Continue Reading…

COVID-19 Coronavirus cases in absolute numbers and per capita – evolution

Graphics of the evolution of the COVID-19 pandemic. Updated regularly since March 31st. Source code for graphic production included.

Excellent graphics of the evolution of the COVID-19 have been made by John Burn-Murdoch for the Financial Times or by Lisa Charlotte Rost for the Grand Continent (observatoire Coronavirus : tendances globales). Not only use they a logarithmic scale, but count […] Continue Reading…