Philippe Massicotte

Uptating Ubuntu packages crashed my renv R project

I am using renv quite a lot. Recently, I had to return to an older project that was using this package to manage package dependencies. When I tried to load tidyverse, I got the following message:

Philippe Massicotte

Removing white spaces around plots in R Markdown / Quarto

When plotting spatial data, such as a geographical map, maintaining a proper aspect ratio is important. Whereas knitr::plot_crop() works fine to crop a file, how can we do the same operation for a figure inside an R Markdown or a Quarto document? Thanks to knitr, this can be done with a hook.

Philippe Massicotte

How to read AMSR2 sea ice data with terra

Today I was trying to read AMSR2 sea ice data. I was surprised to discover that the files do not include coordinates or projection information. Data and coordinates are contained in different files! Maybe to save some disk space ⁉️ The sea ice data is (for example) in a file named Arc_20201010_res3.125_pyres.nc.gz whereas the coordinates are included in a file name LongitudeLatitudeGrid_3.125km_Arctic.nc. Furthermore, I found that the provided coordinates are provided in long/lat format whereas the gridded data are projected 😠

Philippe Massicotte

Beautiful equations in R Markdown and Quarto

Package discovery

When writing dynamic documents in R (either R Markdown or Quarto), it can be useful to display model equations. I recently discovered equatiomatic, a very nice package that can do the job.

Philippe Massicotte

Changing spatial resolution of a raster with terra

Lately, I was working on a project and I needed to change the spatial resolution of a GeoTIFF to match that of another one. After looking around, I posted a question on Stackoverflow. After experimenting around, I decided to blog about my experience of changing the spatial resolution of GeoTIFF rasters.

Philippe Massicotte

Reading multiples CSV files using readr

Data manipulation

If you are beginning in R, chances are that you have used read.csv() to import CSV files into R. While this function works perfectly fine, it can only read one file at a time. Hence, new R programmers often read multiple files successively and combine the data afterward.

Philippe Massicotte

Choosing the right geographic projection with the crsuggest R package

When creating maps, choosing an appropriate geographical projection is often a difficult task (at least for me). There are plenty of projections to choose from, and none can be qualified as the best one. It all depends on what you are trying to achieve. Websites like the projection wizard website offer a playground to experiment with different projections and how they look like depending on where you are looking at on the globe.

Philippe Massicotte

Extracting raster values using the stars R package

For a long time, I have been using the raster package to manipulate raster data in R. Slowly, I am trying to work my way out with the new stars package. In this post, I am exploring different ways to extract values from a raster at different geographic locations. For this exercise, I am using a Landsat 7 image that is provided within the stars package. Each pixel has a resolution of 30 meters.

Philippe Massicotte

How to change the language of dates in R

Recently, I had to make a ggplot2 graphic with data that contained dates. Let’s create some sample data with dates.

Philippe Massicotte

Removing borders around ggplot2 graphs

Recently I was participating in the 30DayMapChallenge where people were invited to make a map based on a different daily theme for one whole month.

Philippe Massicotte

Visualizing the decrease of Artic sea ice extent

It is well known that the Arctic sea ice extent is decreasing at an increasing pace. As stated by the National Snow & Ice Data Center:

Philippe Massicotte