Maps - Projections / Eric Field

Building and Using Tools to See. UVA Architecture + Data Science. IT Director. Instructor.

Public

Edited

Apr 5, 2022

// projection = d3.geoMercator() // this one is commented out because the dropdown above is setting it instead.

// projection.center([-78,38]) // roughly Charlottesville, VA

// projection.scale(1000)

// see the mapLayers cell below, and comment, uncomment, and modify values there.

map = d3.select(mapContainer)

import {getMapData, drawMapLayer} with {map, projection} from "@emfielduva/dvlib_maps"

world = getMapData("world110m")

mapLayers = {

//projection.scale(1000);

//projection.center([-78,38]);

//projection.rotate([78,-38]);

let mapLayers = [];

mapLayers["countries"] = drawMapLayer(map,"countries",world.features,world.idField);

mapLayers["graticules"] = map.select("#graticule").selectAll("path")

.data(graticule.coordinates)

.join("path")

.attr("d", pathGenerator(graticule));

return mapLayers;

}

<style>

#countries path {fill: #ddd; stroke: #ccc}

#graticule path {fill: none; stroke: #eee; stroke-width: 0.5;}

</style>

graticule = d3.geoGraticule10()

pathGenerator = d3.geoPath().projection(projection);

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