Exploring warming stripes with Pharo and Roassal

In the wake of the Global Climate Strike 2019, I tried to create Warming Stripes for Germany using Pharo and Roassal. It's only a few lines of code:

| rawData cleanData neoCSVReader parsedData averageTemperatures view min max normalizer shape elements |

"Obtaining & cleaning data"
rawData := 'https://opendata.dwd.de/climate_environment/CDC/regional_averages_DE/annual/air_temperature_mean/regional_averages_tm_year.txt' asUrl retrieveContents.
cleanData := Character cr join: ((rawData lines) allButFirst: 2).
neoCSVReader := NeoCSVReader new separator: $;.
parsedData := (neoCSVReader on: (ReadStream on: cleanData)) upToEnd.
averageTemperatures := parsedData collect: [ :each | (each at: 19) trim asNumber ].

"Visualization"
view := RTView new.
min := averageTemperatures min.
max := averageTemperatures max.
normalizer := RTMultiLinearColor new.
normalizer colors: ((RTCPDiverging new) scheme:'RdBu').
normalizer command: [ :temperature | 1-((temperature-min)/(max-min))].
shape := RTBox new width: 2; height: 150; color: normalizer.
elements := shape elementsOn: averageTemperatures.
view addAll: elements.
RTHorizontalLineLayout new gapSize: 0; on: elements.
view

Use Pharo 7, Roassal 2 and NeoCSV. Copy the code above to a Playground and inspect it to open the view.
Data for averages temperatures in Germany comes from DWD.