md`# My first exercise: following video`
d3 = require("d3@5")
topojson = require("topojson-client@3")
states = FileAttachment("states48.json").json()
states_features = topojson.feature(states, states.objects.states48)
csv_data = d3.csvParse(await FileAttachment("iowa_counties.csv").text(),({FIPS, MALES, FEMALES
, POP2000}) => [+FIPS, +MALES/+POP2000])
fips = 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
malespct = Array.from(csv_data.values(), d => d[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 Males"]})
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.
