Light Speed Visualization
· 4 min read
Light is the fastest thing in the universe, but how fast is it really? Scroll through the demo below to see how how fast it really is.
3 posts tagged with "visualization"
View All TagsDouble Pendulum Chaos Visualization
· 15 min read
Introduction
What is chaos? Chaos is seen a crowded room, a shattered glass and a uncontrollable dog. At its deepest level, chaos is disorder and unpredictability.
In mathematics and physics, chaos means something very specific
- sensitive to starting conditions
- non-repeating
These two ideas mean that chaotic problems are impossible to solve exactly and difficult to solve approximately. But they're very important problems to work on because chaos theory is the reason that things like the weather, the stock market and fluid flow is so hard to predict. If we can get better at predicting hurricanes or stock market crashes, we can do a better job preparing for them.
COVID-19 Early Spread in South Carolina
· 7 min read
COVID-19 Early Spread in South Carolina
Hover over bubbles to see details
Sources
- SCDHEC News Releases, Information & Videos (COVID-19) Accessed 27 Mar. 2020.
Source Code
View source
CovidSpreadDemo.tsx
import { useBaseUrlUtils } from "@docusaurus/useBaseUrl";
import { useEffect, useId } from "react";
import * as d3 from "d3";
import styles from "./styles.module.css";
import * as topojson from "topojson-client";
export default function LightSpeed() {
let { withBaseUrl } = useBaseUrlUtils();
let id = useId();
useEffect(() => {
const width = 420,
height = 360,
maxRadius = 28;
let maxData = 100;
let wrapper = document.getElementById(id);
let svg = d3
.select(wrapper)
.append("svg")
.attr("width", width)
.attr("id", "SVGMain")
.attr("height", height);
let sc_projection = d3
.geoAlbers()
.parallels([32 + 30 / 60, 34 + 50 / 60])
.rotate([81, 0])
.scale(6000)
.translate([155, -340]);
let path = d3.geoPath().projection(sc_projection);
let tooltip = d3
.select(wrapper)
.append("div")
.attr("class", styles.tooltip)
.style("opacity", 0);
let radius;
let playButton;
let stopButton;
let sizeLegend;
let colorLegend;
let timeLegend;
let virusData;
let deathData;
let centroids = {};
let totalData = {};
let dateOptions = {
month: "long",
day: "numeric",
} satisfies Intl.DateTimeFormatOptions;
let dataLoaded = false;
let currentDay = 0;
let timerID: NodeJS.Timeout | null = null;
let isPlaying = false;
function getDate(day) {
return new Date(2020, 2, 6 + day);
}
function drawButtons() {
let buttonGroup = svg
.append("g")
.attr(
"transform",
"translate(" +
(width - 50) +
"," +
(height - 20 - (2 * maxRadius + 10)) +
")"
)
.attr("class", styles.button);
playButton = buttonGroup
.append("g")
.attr("class", styles.button)
.attr("transform", "translate(0," + (maxRadius - 20) + ")")
.on("click", playAnimation);
playButton
.append("rect")
.attr("rx", 10)
.attr("ry", 10)
.attr("width", maxRadius * 2)
.attr("height", maxRadius)
.attr("x", -maxRadius);
playButton
.append("text")
.attr("x", -maxRadius / 2)
.attr("dy", "1.2em")
.text("Play");
stopButton = buttonGroup
.append("g")
.attr("class", styles.button)
.attr("transform", "translate(0," + (maxRadius * 2 - 10) + ")")
.on("click", stopAnimation);
stopButton
.append("rect")
.attr("rx", 10)
.attr("ry", 10)
.attr("width", maxRadius * 2)
.attr("height", maxRadius)
.attr("x", -maxRadius);
stopButton
.append("text")
.attr("x", -maxRadius / 2 - 2)
.attr("dy", "1.2em")
.text("Stop");
}
function drawLegend() {
let d1 = maxData / 2;
let d2 = maxData / 4;
sizeLegend = svg
.append("g")
.attr("class", styles.sizeLegend)
.attr(
"transform",
"translate(" + 60 + "," + (height - 20) + ")"
)
.selectAll("g")
.data([
Math.floor(d1 / 10) * 10,
Math.floor(d2 / 10) * 10,
Math.floor(maxData / 10) * 10,
])
.enter()
.append("g");
sizeLegend
.append("circle")
.attr("cy", function (d) {
return -radius(d);
})
.attr("r", radius);
sizeLegend
.append("text")
.attr("y", function (d) {
return -2 * radius(d);
})
.attr("x", function (d) {
return -radius(d) / 100;
})
.attr("dy", "1.2em")
.text(d3.format(".1s"));
colorLegend = svg
.append("g")
.attr("class", styles.colorLegend)
.attr(
"transform",
"translate(" +
60 +
"," +
(height - (20 + 2 * maxRadius)) +
")"
)
.selectAll("g")
.data([
[0, "Cases", "#aa1111"],
[1, "Deaths", "#000"],
])
.enter()
.append("g");
colorLegend
.append("circle")
.attr("cx", function (d) {
return d[0] * 60 - 30;
})
.attr("cy", -maxRadius)
.attr("r", maxRadius)
.style("fill", function (d) {
return d[2];
});
colorLegend
.append("text")
.attr("x", function (d) {
return d[0] * 60 - 30;
})
.attr("y", -maxRadius - 10)
.attr("dy", "1.2em")
.text(function (d) {
return d[1];
});
timeLegend = svg
.append("g")
.attr("class", styles.timeLegend)
.attr(
"transform",
"translate(" +
60 +
"," +
(height - (20 + 32 + 4 * maxRadius)) +
")"
)
.data([0]);
timeLegend
.append("rect")
.attr("width", maxRadius * 2 + 4)
.attr("rx", 10)
.attr("ry", 10)
.attr("height", maxRadius)
.attr("x", -maxRadius - 2);
timeLegend
.append("text")
.attr("y", maxRadius / 2 + 3)
.text(function (d) {
return getDate(d).toLocaleDateString("en-US", dateOptions);
});
}
function load_initial_data() {
maxData = 0;
for (let day in virusData.columns) {
let dayData = {};
for (let county in virusData[day]) {
dayData[county] = [
virusData[day][county],
deathData[day][county],
];
maxData = Math.max(maxData, virusData[day][county]);
}
totalData[day] = dayData;
}
radius = d3.scaleSqrt().domain([0, maxData]).range([0, maxRadius]);
drawLegend();
drawButtons();
fill_initial_data();
}
function inputInitialData() {
d3.csv(
withBaseUrl("covid-spread-sc/SC_VIRUS_TOTAL_CUMULATIVE.csv")
).then(function (total_data) {
virusData = total_data;
if (dataLoaded) {
load_initial_data();
} else {
dataLoaded = true;
}
});
d3.csv(
withBaseUrl("covid-spread-sc/SC_VIRUS_DEATH_CUMULATIVE.csv")
).then(function (total_data) {
deathData = total_data;
if (dataLoaded) {
load_initial_data();
} else {
dataLoaded = true;
}
});
}
function fill_initial_data() {
let dVList = Object.entries(totalData[0]).map(([key, value]) => {
return { key, value };
});
svg.selectAll(`path.${styles.countyFill}`)
.data(dVList)
.style("fill-opacity", function (d: any) {
if (+d.value[0] > 0) return 0;
return 1;
})
.on("mouseover", function (evt: MouseEvent, d: any) {
if (+d.value[0] >= 1) return;
let firstS = "";
let secondS = "";
if (d.value[0] != 1) firstS = "s";
if (d.value[1] != 1) secondS = "s";
let tooltipText =
"<bold>" +
d.key +
"</bold>" +
"<br/>" +
+d.value[0] +
" case" +
firstS +
"<br/>" +
+d.value[1] +
" death" +
secondS;
tooltip.transition().duration(200).style("opacity", 0.9);
tooltip
.html(tooltipText)
.style("left", evt.pageX + "px")
.style("top", evt.pageY - 28 + "px");
})
.on("mouseout", function (d) {
tooltip.transition().duration(500).style("opacity", 0);
});
let countyLocations = svg
.append("g")
.attr("class", styles.bubbleContainer)
.selectAll(".county-centroid")
.data(dVList)
.enter()
.append("g")
.attr("class", "county-centroid")
.attr("transform", function (d: any) {
return "translate(" + centroids[d.key] + ")";
});
let cases = countyLocations
.append("circle")
.attr("class", styles.case)
.attr("r", function (d: any) {
return radius(+d.value[0]);
});
countyLocations
.append("circle")
.attr("class", styles.death)
.attr("r", function (d: any) {
return radius(+d.value[1]);
});
countyLocations
.append("circle")
.attr("class", styles.caseBoundary)
.attr("r", function (d: any) {
return radius(+d.value[0]);
})
.on("mouseover", function (evt: MouseEvent, d: any) {
let firstS = "";
let secondS = "";
if (d.value[0] != 1) firstS = "s";
if (d.value[1] != 1) secondS = "s";
let tooltipText =
"<bold>" +
d.key +
"</bold>" +
"<br/>" +
+d.value[0] +
" case" +
firstS +
"<br/>" +
+d.value[1] +
" death" +
secondS;
tooltip.transition().duration(200).style("opacity", 0.9);
tooltip
.html(tooltipText)
.style("left", evt.pageX + "px")
.style("top", evt.pageY - 28 + "px");
})
.on("mouseout", function (d) {
tooltip.transition().duration(500).style("opacity", 0);
});
}
function playAnimation() {
if (isPlaying) return;
isPlaying = true;
if (currentDay >= Object.keys(virusData).length - 2) {
currentDay = 0;
transitionToDay(currentDay);
}
timerID = setInterval(() => updateForNextDay(), 605);
}
function stopAnimation() {
if (!isPlaying) return;
if (timerID != null) {
clearInterval(timerID);
}
isPlaying = false;
}
function updateForNextDay() {
currentDay = (currentDay + 1) % (Object.keys(totalData).length - 2);
transitionToDay(currentDay);
}
function transitionToDay(day) {
if (day >= Object.keys(virusData).length - 2) {
stopAnimation();
}
let dVList = Object.entries(totalData[day]).map(([key, value]) => {
return { key, value };
});
let countyLocations = svg
.selectAll(".county-centroid")
.data(dVList);
let cases = countyLocations.select(`circle.${styles.case}`);
let deaths = countyLocations.select(`circle.${styles.death}`);
let boundaries = countyLocations.select(
`circle.${styles.caseBoundary}`
);
svg.select(`.${styles.timeLegend}`)
.data([day])
.select("text")
.text(function (d) {
return getDate(d).toLocaleDateString("en-US", dateOptions);
});
if (day == 0) {
cases.attr("r", function (d: any) {
return radius(+d.value[0]);
});
deaths.attr("r", function (d: any) {
return radius(+d.value[1]);
});
boundaries.attr("r", function (d: any) {
return radius(+d.value[0]);
});
svg.selectAll(`path.${styles.countyFill}`)
.data(dVList)
.style("fill-opacity", function (d: any) {
if (+d.value[0] >= 1) return 0;
return 1;
});
} else {
let transitionEase = d3.easeLinear;
let duration = 600;
cases
.transition()
.duration(duration)
.ease(transitionEase)
.attr("r", function (d: any) {
return radius(+d.value[0]);
});
deaths
.transition()
.duration(duration)
.ease(transitionEase)
.attr("r", function (d: any) {
return radius(+d.value[1]);
});
boundaries
.transition()
.duration(duration)
.ease(transitionEase)
.attr("r", function (d: any) {
return radius(+d.value[0]);
});
svg.selectAll(`path.${styles.countyFill}`)
.data(dVList)
.transition()
.ease(transitionEase)
.duration(duration)
.style("fill-opacity", function (d: any) {
if (+d.value[0] >= 1) return 0;
return 1;
});
}
}
d3.json(withBaseUrl("covid-spread-sc/states.json")).then(function (
sc: any
) {
let state = topojson.feature(sc, sc.objects.places);
svg.append("path")
.datum(state)
.attr("d", path)
.attr("class", styles.state);
});
d3.json(withBaseUrl("covid-spread-sc/counties.json")).then(function (
counties: any
) {
let features = topojson.feature(
counties,
counties.objects.places
).features;
svg.append("g")
.selectAll(`path.${styles.countyFill}`)
.data(
features.sort(function (a, b) {
if (b.properties.NAME > a.properties.NAME) return -1;
if (b.properties.NAME < a.properties.NAME) return 1;
return 0;
})
)
.enter()
.append("path")
.attr("d", path)
.attr("class", styles.countyFill);
svg.append("path")
.datum(
topojson.mesh(
counties,
counties.objects.places,
function (a, b) {
return a !== b;
}
)
)
.attr("d", path)
.attr("class", styles.countyBoundary);
svg.append("path")
.datum(
topojson.mesh(
counties,
counties.objects.places,
function (a, b) {
return a === b;
}
)
)
.attr("d", path)
.attr("class", styles.countyBoundary);
for (let i = 0; i < features.length; i++) {
let centroid = path.centroid(features[i]);
if (features[i].properties.NAME == "Charleston") {
centroid = [centroid[0] - 15, centroid[1] + 12];
}
centroids[features[i].properties.NAME] = centroid;
}
inputInitialData();
});
}, [id]);
return <div className={styles.wrapper} id={id} />;
}