Visual Data Science at the Johannes Kepler University Linz, Austria.
Published
Edited
Mar 31, 2022
7 stars
data = [ // x & y will be overwritten by the simulation
{"x_init":150, "y_init":80, "r":20, "fill":"#990000", "fill_opacity": 0.4},
{"x_init":155, "y_init":85, "r":30, "fill":"#009900", "fill_opacity": 0.4},
{"x_init":160, "y_init":95, "r":35, "fill":"#000099", "fill_opacity": 0.4},
{"x_init":330, "y_init":165, "r":20, "fill":"#009999", "fill_opacity": 0.4},
{"x_init":330, "y_init":165, "r":30, "fill":"#900099", "fill_opacity": 0.4}
];
drawPlot = () => {
console.log('plot')
let points = d3.select("#scatterplot").selectAll("circle").data(data);
let labels = d3.select("#scatterplot").selectAll("text").data(data);
// For new points and labels (not drawn yet, e.g., when page loads), draw them
points.enter().append("circle")
.attr("cx", d => d.x)
.attr("cy", d => d.y)
.attr("r", d => d.r)
.attr("fill", d => d.fill)
.attr("fill-opacity", d => d.fill_opacity);
labels.enter().append("text")
.text(d => d.x_init + ", " + d.y_init)
.attr("x", d => d.x + d.r)
.attr("y", d => d.y)
.attr("alignment-baseline", "middle"); // Vertically align text with point
// For existing points already drawn, update their locations,
// using (updated) values in data
points
.attr("cx", d => d.x)
.attr("cy", d => d.y);
labels
.attr("x", d => d.x + d.r)
.attr("y", d => d.y);
}
viewof sim = {
const sim = d3.forceSimulation(data)
.force("collision", d3.forceCollide(d => d.r)) // Repulsion force
.force("x_force", d3.forceX(d => d.x_init)) // Each point attacted to its center x and y
.force("y_force", d3.forceY(d => d.y_init))
.on('tick', drawPlot) // Redraws scatterplot at every simulation "tick"
.stop();
if (repel) {
sim.force("collision", d3.forceCollide((d) => d.r)); // Add repulsion force back
} else {
sim.force("collision", null); // Removes repulsion force
}
sim.alpha(1); // Alpha value of 1 resets simulation back to beginning
sim.alphaMin(0.5); // Simulation ends quick --> necessary to toggle the checkbox
sim.restart();
return sim;
}
One platform to build and deploy the best data apps
Experiment and prototype by building visualizations in live JavaScript notebooks. Collaborate with your team and decide which concepts to build out.
Use Observable Framework to build data apps locally. Use data loaders to build in any language or library, including Python, SQL, and R.
Seamlessly deploy to Observable. Test before you ship, use automatic deploy-on-commit, and ensure your projects are always up-to-date.