//Required for Jenks Classifier
simple = require("simple-statistics@7.0.7/dist/simple-statistics.min.js")
//require d3 v5 library
d3 = require("d3@5");
//require topojson-client v3 library
topojson = require("topojson-client@3");
//load json file
countiesIL = FileAttachment("countiesIL.json").json();
//extract json components
counties = topojson.feature(countiesIL, countiesIL.objects.geojson);
//load particular columns and derived columns from csv file
csv_data = d3.csvParse(await FileAttachment("Data@2.csv").text(),({County, c2020, c2030}) => [County, [(+c2030/c2020 - 1)*100]]);
//this is how to take the values of a variable (column) from all variables you created from the csv file
//extract derived column (1), 0 start index
growth20to30 = Array.from(csv_data.values(), d => d[1][0]);
//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: ["Projected 2020-2030 % Population Growth"]});
color = d3.scaleThreshold()
.domain([-2, 0, 3.5, 12])
.range(d3.schemeRdBu[5])
import {legend} from "@d3/color-legend"
format = d => `${d}%`
width = 200
height = 400
margin = 0
projection = d3.geoTransverseMercator().rotate([94,0]).fitExtent([[80, 80], [width, height]], counties);
path = d3.geoPath().projection(projection);
choropleth = {
const svg = d3.create("svg")
.attr("viewBox", [0, 0, width, height]);
svg.append("g")
.attr("transform", "translate(0,50)")
.append(() =>
legend({
color: color,
title: data.title,
width: 200,
tickFormat: d => d + "%"
})
);
svg.append("g")
.selectAll("path")
.data(counties.features)
.join("path")
//Line colors
.attr("stroke", "black")
//nothing
.attr("stroke-linejoin", "round")
//width of lines
.attr("stroke-width", 1)
//reading the data
.attr("d", path)
//coloring of data
.attr("fill", d => color(data.get(d.properties.COUNTY_NAM)))
//???
.append("title")
//hover text
.text(d => "Predicted growth in " + d.properties.COUNTY_NAM + " county: " + Math.round(data.get(d.properties.COUNTY_NAM) * 100) / 100 + "%");
return svg.node();
}
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