I'm a professor of mathematics at the University of North Carolina Asheville. I've also done a fair amount of consulting work over the years focusing on scientific and data visualization.
I'm happy to be part of the first Observable Ambassador's cohort.
NC Congressional DistrictsTrivariate choropleth for racial composition in the USRacial distribution in NC3D Choropleth for NC County PopulationsNC CountiesTriangulated Canadian Provinces (separate)Triangulated NC CountiesAn X3D GlobeCanadian Elections 3DWNC SurroundElectoral Results TilegramThe new Electoral CollegeElectoral MapGPX rides with Leaflet and OSMOld encoded polyline rides with LeafletGPX rides with Maplibre and MaptilerBuncombe county votingThe NC Congressional redistricting battleHexapolis 538Zillow Home PricesSetting up HexapolisCOVID curvesThirty day Map Challenge - Day 1Simple grid cartogram2020 Census Apportionment TilegramMass shootings in the USHBCUsNC State Legislative Elections 2022Hierarchical Structure of the US RegionsIndigenous territories of the SoutheastD3.force to desired positionPopulation Choropleth for the Contiguous US StatesPlotting a few points on a mapMutliple bubble maps for CSV dataWorld population bubble mapReproductive rights and ... ??Gerrymandering Hexapolis by handVisualizations of gun ownership dataIncome inequality in North Carolina
WNC Zoom
wnc_zoom = {
again;
let w = window.innerWidth;
let h;
if (window.innerHeight < 2500) {
h = window.innerHeight;
} else {
h = 0.6 * w;
}
let div = d3
.create('div')
.style('width', `${w}px`)
.style('height', `${h}px`)
.style('position', 'relative');
let canvas = div
.append('canvas')
.attr('width', w)
.attr('height', h);
let context = canvas.node().getContext('2d');
let r = 9;
let projection = d3
.geoOrthographic()
.translate([w / 2, h / 2])
.scale(r);
let path = d3.geoPath(projection, context);
if (speed_test() < 50) {
let a0 = 40;
let ma = 82.88;
let spinSpeed = .2;
let s = ((8 * h) / r) ** (spinSpeed / (-a0 + ma));
canvas.angle = a0;
while (canvas.angle < ma) {
r = s * r;
projection.rotate([(canvas.angle += spinSpeed), -35.65]).scale(r);
context.clearRect(0, 0, w, h);
context.lineWidth = 2;
context.strokeStyle = 'black';
context.fillStyle = d3.interpolateRdBu(0.66);
context.beginPath();
context.arc(w / 2, h / 2, r, 0, 2 * Math.PI);
context.fill();
context.stroke();
draw(context, canvas, projection, path, r, w, h);
yield div.node();
}
}
if (r == 9) {
canvas.angle = 83;
r = 4800;
}
projection.rotate([canvas.angle, -35.65]).scale(r);
context.clearRect(0, 0, w, h);
context.lineWidth = 2;
context.strokeStyle = 'black';
context.fillStyle = d3.interpolateRdBu(0.66);
context.beginPath();
context.arc(w / 2, h / 2, r, 0, 2 * Math.PI);
context.fill();
context.stroke();
draw(context, canvas, projection, path, r, w, h);
yield div.node();
let svg = div
.append('svg')
.attr('width', w - 2)
.attr('height', h - 2)
.style('position', 'absolute')
.style('top', 0)
.style('left', 0);
let svg_path = d3.geoPath(projection);
svg
.append('path')
.attr('d', svg_path(features.d11_boundary.features[0]))
.style('stroke', 'black')
.style('stroke-linejoin', 'round')
.style('fill', 'rgba(0,0,0,0)')
.style("cursor", "pointer")
.on('mouseenter', function() {
d3.select(this).style('stroke-width', '3px');
})
.on('mouseleave', function() {
d3.select(this).style('stroke-width', '1px');
})
.on('click', function() {
window.open("https://wncviz.com/demos/Gerrymandering_in_NC/");
});
}
function draw(context, canvas, projection, path, r, angle, w, h) {
let ma = 82.88;
let landColor = '#fafafa';
// The land
context.lineWidth = 1;
context.strokeStyle = 'black';
context.fillStyle = landColor;
context.beginPath();
path(features.land);
context.fill();
context.stroke();
let ca = 65;
if (canvas.angle > ca) {
context.fillStyle = landColor;
context.strokeStyle = `rgba(0,0,0,${((canvas.angle - ca) / (ma - ca)) **
2})`;
context.beginPath();
path(features.states);
context.fill();
context.stroke();
features.d11_VTDs.features.forEach(function(d) {
context.strokeStyle = `rgba(0,0,0,${0.2 *
((canvas.angle - ca) / (ma - ca)) ** 2})`;
let c = d3.rgb(d3.interpolateRdBu(d.properties.dprop));
c.opacity = 0.75 * ((canvas.angle - ca) / (ma - ca)) ** 2;
context.fillStyle = c.toString();
context.beginPath();
path(d);
context.fill();
context.stroke();
});
context.strokeStyle = `rgba(0,0,0,${((canvas.angle - ca) / (ma - ca)) **
2})`;
context.lineWidth = 1;
context.beginPath();
path(features.d11_boundary);
context.stroke();
}
}
ortho_zoom = FileAttachment("ortho_zoom@3.json").json()
features = {
let land = topojson.feature(ortho_zoom, ortho_zoom.objects.land);
let states = topojson.feature(ortho_zoom, ortho_zoom.objects.states);
let d11_boundary = topojson.feature(
ortho_zoom,
ortho_zoom.objects.D11Boundary
);
let d11_VTDs = topojson.feature(ortho_zoom, ortho_zoom.objects.D11_VTDs);
return {
land: land,
states: states,
d11_boundary: d11_boundary,
d11_VTDs: d11_VTDs
};
}
import { Button } from '@observablehq/inputs'
d3 = require('d3-selection@2', 'd3-shape@2', 'd3-geo@2', 'd3-scale-chromatic@2', 'd3-color@2')
topojson = require("topojson-client@3")
function speed_test() {
let t = Date.now();
let T = 0;
for (let i = 0; i < 10 ** 7; i++) {
T = T + i;
}
return Date.now() - t;
}
{
// draw(context, canvas, projection, path, r, angle, w, h)
let r = 1800;
let w = 1200;
let h = 600;
let canvas = d3
.create('canvas')
.attr('width', w)
.attr('height', h);
let context = canvas.node().getContext('2d');
let a = 73;
canvas.angle = a;
let projection = d3
.geoOrthographic()
.translate([w / 2, h / 2])
.rotate([a, -35.65])
.scale(r);
let path = d3.geoPath(projection, context);
context.lineWidth = 2;
context.strokeStyle = 'black';
context.fillStyle = d3.interpolateRdBu(0.66);
context.beginPath();
context.arc(w / 2, h / 2, r, 0, 2 * Math.PI);
context.fill();
context.stroke();
let ma = 82.88;
let landColor = '#fafafa';
// The land
context.lineWidth = 1;
context.strokeStyle = 'black';
context.fillStyle = landColor;
context.beginPath();
path(features.land);
context.fill();
context.stroke();
let ca = 65;
if (canvas.angle > ca) {
context.fillStyle = landColor;
context.strokeStyle = `rgba(0,0,0,${((canvas.angle - ca) / (ma - ca)) **
2})`;
context.beginPath();
path(features.states);
context.fill();
context.stroke();
context.lineWidth = 0.6;
features.d11_VTDs.features.forEach(function(d) {
context.strokeStyle = `rgba(0,0,0,0.2)`;
let c = d3.rgb(d3.interpolateRdBu(d.properties.dprop));
c.opacity = 1; // 0.75 * ((canvas.angle - ca) / (ma - ca)) ** 2;
context.fillStyle = c.toString();
context.beginPath();
path(d);
context.fill();
context.stroke();
});
context.strokeStyle = `rgba(0,0,0,${((canvas.angle - ca) / (ma - ca)) **
2})`;
context.lineWidth = 1;
context.beginPath();
path(features.d11_boundary);
context.stroke();
}
return canvas.node();
}
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