deltas = [-100, -4, -1, 0]
map = {
const svg = d3.create("svg")
.attr("viewBox", [0, 0, width, height]);
const tile = d3.tile()
.extent([[0, 0], [width, height]])
.tileSize(512)
.clampX(false);
const zoom = d3.zoom()
.scaleExtent([1 << 8, 1 << 22])
.extent([[0, 0], [width, height]])
.on("zoom", (event) => zoomed(event.transform));
const levels = svg.append("g")
.attr("pointer-events", "none")
.selectAll("g")
.data(deltas)
.join("g")
.style("opacity", showlayers ? 0.3 : null);
svg
.call(zoom)
.call(zoom.transform, mutable transform);
function zoomed(transform) {
mutable transform = transform;
levels.each(function(delta) {
const tiles = tile.zoomDelta(delta)(transform);
d3.select(this)
.selectAll("image")
.data(tiles, d => d)
.join("image")
.attr("xlink:href", d => url(...d3.tileWrap(d)))
.attr("x", ([x]) => (x + tiles.translate[0]) * tiles.scale)
.attr("y", ([, y]) => (y + tiles.translate[1]) * tiles.scale)
.attr("width", tiles.scale)
.attr("height", tiles.scale);
});
}
return svg.node();
}
mutable transform = d3.zoomIdentity.translate(width >> 1, height >> 1).scale(1 << 12)
// Kartendaten: © [OpenStreetMap](https://openstreetmap.org/copyright)-Mitwirkende, SRTM | Kartendarstellung: © [OpenTopoMap](http://opentopomap.org/) (CC-BY-SA)
url = (x, y, z) => `https://tile.opentopomap.org/${z}/${x}/${y}.png`
d3 = require("d3@7", "d3-tile@1")
height = 600 // note: observable sets a responsive *width*
Purpose-built for displays of data
Observable is your go-to platform for exploring data and creating expressive data visualizations. Use reactive JavaScript notebooks for prototyping and a collaborative canvas for visual data exploration and dashboard creation.
