md`# Matti's first exercise`
d3 = require("d3@5")
topojson = require("topojson-client@3")
virginia = FileAttachment("cd51_106.json").json()
county_features = topojson.feature(virginia, virginia.objects.cd51_106)
csv_data = d3.csvParse(await FileAttachment("FoodAccessResearchAtlasData2019 copy.csv").text(),({CensusTract, Pop2010, TractKids}) => [CensusTract, [+TractKids, (+TractKids/+Pop2010)*100]])
//this is how to take the values of a variable (column) from all variables you created from the csv file
Percentage_of_kids = 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: [" Percentage of Kids in Virginia's Counties "]})
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.
