Building and Using Tools to See.
UVA Architecture + Data Science. IT Director. Instructor.
<svg width="600" height="300">
<g id="layer1"></g>
<text id="mytext" x="100" y="250"></text>
<style>
#mytext {font-family: Arial,Helvetica,sans-serif; font-size: 30px; fill: red;}
</style>
</svg>
mutable log = "" // a mutable variable that we can use to log things to for testing and debugging.
data = [
{name: "one", value: 1},
{name: "two", value: 2},
{name: "three", value: 3},
{name: "four", value: 4},
{name: "five", value: 5}
]
viz.select("#layer1").selectAll(".mycircle")
.data(data)
.join("circle")
.classed("mycircle", true)
.attr("cx",d => d.value * 100)
.attr("cy", 150)
.attr("r", d => d.value * 10)
.style("fill","steelblue")
.on("mouseover", highlight) // this is the critical part, calling the highlight function below
.on("mouseout", unhighlight) // and then clear it when the mouse leaves the element
highlight = (evt,d) => {
let mousedoverElem = evt.currentTarget;
mutable log = mousedoverElem; // this is for demonstration, and debugging.
d3.select(mousedoverElem).style("stroke","blue").style("stroke-width","3px"); // give it a yellow stroke when we highlight it
putText(evt,d); // and while were at is, let's call putText also using the same event and data.
}
unhighlight = (evt,d) => {
let mousedoverElem = evt.currentTarget;
d3.select(mousedoverElem).style("stroke","").style("stroke-width",""); // return styles to null to reset to defaults
clearText();
}
putText = (evt,d) => {
viz.select("#mytext").text("this item is: " + d.name);
}
clearText = () => {
viz.select("#mytext").text("");
}
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.