md`# My first exercise.2`
d3 = require("d3@5")
topojson = require("topojson-client@3")
kanecounty = FileAttachment("kanecounty2.json").json()
kanecounty_features1 = topojson.feature(kanecounty, kanecounty.objects.kanecounty2)
csv_data = d3.csvParse(await FileAttachment("IllinoisKaneCounty.csv").text(),({CensusTract, Pop2010, TractSNAP}) => [CensusTract, [TractSNAP, +TractSNAP/+Pop2010]])
census_tract = Array.from(csv_data.values(), d => d[0])
//this is how to take the values of a variable (column) from all variables you created from the csv file
snap_percent = Array.from(csv_data.values(), d => d[1][1])
//this is how you map the id column to the values. We will use this for joining with topojson later.
data = Object.assign(new Map(csv_data), {title: ["census_tract", "snap_percent"]})
Purpose-built for displays of data
Observable is your go-to platform for exploring data and creating expressive data visualizations. Use reactive JavaScript notebooks for prototyping and a collaborative canvas for visual data exploration and dashboard creation.
