3e:null 3f:["$","title",null,{"children":"Projections comparison: | Éléonore | Observable"}] 45:T648,map = { const outline = ({type: "Sphere"}); const graticule = d3.geoGraticule10(); const land = topojson.feature(world, world.objects.land); const width = 1100; const heightRed = fitWidth(d3.geoMercator()); const heightGreen = fitWidth(d3.geoEqualEarth()); //const height = Math.max(heightRed, heightGreen); const meanHeight = (heightRed + heightGreen) / 2 const context = DOM.context2d(width, heightRed); function render(projection, color) { const path = d3.geoPath(projection, context); context.fillStyle = context.strokeStyle = color; context.save(); context.beginPath(), path(outline), context.clip(); context.beginPath(), path(graticule), context.globalAlpha = 0.3, context.stroke(); context.beginPath(), path(land), context.globalAlpha = 1.0, context.fill(); context.restore(); context.beginPath(), path(outline), context.stroke(); } context.fillStyle = "#fff"; context.fillRect(0, 0, width, heightRed); // Red map context.save(); context.translate(0, meanHeight/4) render(d3.geoMercator(), "#f03e3e"); context.restore(); // Add green map context.save(); context.globalCompositeOperation = "multiply"; context.translate(0, meanHeight/4) render(d3.geoEqualEarth(), "#006E51"); context.restore(); return context.canvas; function fitWidth(projection) { const [[x0, y0], [x1, y1]] = d3.geoPath(projection.fitWidth(width, outline)).bounds(outline); const dy = Math.ceil(y1 - y0), l = Math.min(Math.ceil(x1 - x0), dy); projection.scale(projection.scale() * (l - 1) / l).precision(0.2); return dy; } }46:T15ba,projections = [ {name: "Airy’s minimum error", value: d3.geoAiry}, {name: "Aitoff", value: d3.geoAitoff}, {name: "American polyconic", value: d3.geoPolyconic}, {name: "armadillo", value: d3.geoArmadillo}, {name: "August", value: d3.geoAugust}, {name: "azimuthal equal-area", value: d3.geoAzimuthalEqualArea}, {name: "azimuthal equidistant", value: d3.geoAzimuthalEquidistant}, {name: "Baker dinomic", value: d3.geoBaker}, {name: "Berghaus’ star", value: d3.geoBerghaus}, {name: "Bertin’s 1953", value: d3.geoBertin1953}, {name: "Boggs’ eumorphic", value: d3.geoBoggs}, {name: "Boggs’ eumorphic (interrupted)", value: d3.geoInterruptedBoggs}, {name: "Bonne", value: d3.geoBonne}, {name: "Bottomley", value: d3.geoBottomley}, {name: "Bromley", value: d3.geoBromley}, {name: "Butterfly (gnomonic)", value: d3.geoPolyhedralButterfly}, {name: "Butterfly (Collignon)", value: d3.geoPolyhedralCollignon}, {name: "Butterfly (Waterman)", value: d3.geoPolyhedralWaterman}, {name: "Collignon", value: d3.geoCollignon}, // {name: "conic conformal", value: d3.geoConicConformal}, // Not suitable for world maps. {name: "conic equal-area", value: d3.geoConicEqualArea}, {name: "conic equidistant", value: d3.geoConicEquidistant}, {name: "Craig retroazimuthal", value: d3.geoCraig}, {name: "Craster parabolic", value: d3.geoCraster}, {name: "cylindrical equal-area", value: d3.geoCylindricalEqualArea}, {name: "cylindrical stereographic", value: d3.geoCylindricalStereographic}, {name: "Eckert I", value: d3.geoEckert1}, {name: "Eckert II", value: d3.geoEckert2}, {name: "Eckert III", value: d3.geoEckert3}, {name: "Eckert IV", value: d3.geoEckert4}, {name: "Eckert V", value: d3.geoEckert5}, {name: "Eckert VI", value: d3.geoEckert6}, {name: "Eisenlohr conformal", value: d3.geoEisenlohr}, {name: "Equal Earth", value: d3.geoEqualEarth}, {name: "Equirectangular (plate carrée)", value: d3.geoEquirectangular}, {name: "Fahey pseudocylindrical", value: d3.geoFahey}, {name: "flat-polar parabolic", value: d3.geoMtFlatPolarParabolic}, {name: "flat-polar quartic", value: d3.geoMtFlatPolarQuartic}, {name: "flat-polar sinusoidal", value: d3.geoMtFlatPolarSinusoidal}, {name: "Foucaut’s stereographic equivalent", value: d3.geoFoucaut}, {name: "Foucaut’s sinusoidal", value: d3.geoFoucautSinusoidal}, {name: "general perspective", value: d3.geoSatellite}, {name: "Gilbert’s two-world", value: d3.geoGilbert}, {name: "Gingery", value: d3.geoGingery}, {name: "Ginzburg V", value: d3.geoGinzburg5}, {name: "Ginzburg VI", value: d3.geoGinzburg6}, {name: "Ginzburg VIII", value: d3.geoGinzburg8}, {name: "Ginzburg IX", value: d3.geoGinzburg9}, {name: "Goode’s homolosine", value: d3.geoHomolosine}, {name: "Goode’s homolosine (interrupted)", value: d3.geoInterruptedHomolosine}, {name: "gnomonic", value: d3.geoGnomonic}, {name: "Gringorten square", value: d3.geoGringorten}, {name: "Gringorten quincuncial", value: d3.geoGringortenQuincuncial}, {name: "Guyou square", value: d3.geoGuyou}, {name: "Hammer", value: d3.geoHammer}, {name: "Hammer retroazimuthal", value: d3.geoHammerRetroazimuthal}, {name: "HEALPix", value: d3.geoHealpix}, {name: "Hill eucyclic", value: d3.geoHill}, {name: "Hufnagel pseudocylindrical", value: d3.geoHufnagel}, {name: "Kavrayskiy VII", value: d3.geoKavrayskiy7}, {name: "Lagrange conformal", value: d3.geoLagrange}, {name: "Larrivée", value: d3.geoLarrivee}, {name: "Laskowski tri-optimal", value: d3.geoLaskowski}, // {name: "Littrow retroazimuthal", value: d3.geoLittrow}, // Not suitable for world maps. {name: "Loximuthal", value: d3.geoLoximuthal}, {name: "Mercator", value: d3.geoMercator}, {name: "Miller cylindrical", value: d3.geoMiller}, {name: "Mollweide", value: d3.geoMollweide}, {name: "Mollweide (Goode’s interrupted)", value: d3.geoInterruptedMollweide}, {name: "Mollweide (interrupted hemispheres)", value: d3.geoInterruptedMollweideHemispheres}, {name: "Natural Earth", value: d3.geoNaturalEarth1}, {name: "Natural Earth II", value: d3.geoNaturalEarth2}, {name: "Nell–Hammer", value: d3.geoNellHammer}, {name: "Nicolosi globular", value: d3.geoNicolosi}, {name: "orthographic", value: d3.geoOrthographic}, {name: "Patterson cylindrical", value: d3.geoPatterson}, {name: "Peirce quincuncial", value: d3.geoPeirceQuincuncial}, {name: "rectangular polyconic", value: d3.geoRectangularPolyconic}, {name: "Robinson", value: d3.geoRobinson}, {name: "sinusoidal", value: d3.geoSinusoidal}, {name: "sinusoidal (interrupted)", value: d3.geoInterruptedSinusoidal}, {name: "sinu-Mollweide", value: d3.geoSinuMollweide}, {name: "sinu-Mollweide (interrupted)", value: d3.geoInterruptedSinuMollweide}, {name: "stereographic", value: d3.geoStereographic}, {name: "Times", value: d3.geoTimes}, {name: "Tobler hyperelliptical", value: d3.geoHyperelliptical}, {name: "transverse Mercator", value: d3.geoTransverseMercator}, {name: "Van der Grinten", value: d3.geoVanDerGrinten}, {name: "Van der Grinten II", value: d3.geoVanDerGrinten2}, {name: "Van der Grinten III", value: d3.geoVanDerGrinten3}, {name: "Van der Grinten IV", value: d3.geoVanDerGrinten4}, {name: "Wagner IV", value: d3.geoWagner4}, {name: "Wagner VI", value: d3.geoWagner6}, {name: "Wagner VII", value: d3.geoWagner7}, {name: "Werner", value: () => d3.geoBonne().parallel(90)}, {name: "Wiechel", value: d3.geoWiechel}, {name: "Winkel tripel", value: d3.geoWinkel3} ]47:[{"id":"85b1800385297a1dfa0e2a821f55b7c95866affef1cb64b10f22a923f79498bf8a786105ab97d8953c1b25c0bcf223c7f6342046349b8bb0ea088d2138896138","href":"https://static.observableusercontent.com/files/85b1800385297a1dfa0e2a821f55b7c95866affef1cb64b10f22a923f79498bf8a786105ab97d8953c1b25c0bcf223c7f6342046349b8bb0ea088d2138896138","name":"world.json","type":"application/json","lastModified":1689595167479.692,"size":545533}] 43:{"id":"5d71adac8d325d13","slug":"mercator-vs-equal-earth","title":"Projections comparison:","thumbnail":"a1bf14c0da04f89445166cae8ffa10cb3eb8aed70cc793e9f316d96fd3ec0445","access_level":"public","create_time":"$D2026-10-14T13:44:01.920Z","update_time":"$D2026-10-14T15:48:07.491Z","view_time":null,"first_public_time":"$D2026-10-14T15:54:50.985Z","has_unpublished_edits":null,"fork":{"id":"e1ede52dc01ead30","slug":"projection-comparison","title":"Projection comparison","owner":{"id":"863951e3ebe4c0ae","login":"d3","name":"D3"}},"stars":0,"starred":false,"owner":{"type":"team","id":"5a9a75a747cb01fe","login":"eleonore9","name":"Éléonore","avatar_url":"https://avatars-next.observableusercontent.com/f02bb17abd0c6c5bf2635bef76a16323ef091dbd4e41cbb1a5ed10e3ea21fbb5","tier":"starter_2024","bio":"Data viz dev 👩🏿‍💻📊🌍"},"version":319,"publish_version":319,"role":null,"authored":false,"authors":[{"type":"individual","id":"b0524eb6eebd4534","login":"eleonore9","name":"Éléonore","avatar_url":"https://avatars-next.observableusercontent.com/f02bb17abd0c6c5bf2635bef76a16323ef091dbd4e41cbb1a5ed10e3ea21fbb5","tier":null,"bio":"Data viz dev 👩🏿‍💻📊🌍"}],"members":[{"type":"team","id":"5a9a75a747cb01fe","login":"eleonore9","name":"Éléonore","avatar_url":"https://avatars-next.observableusercontent.com/f02bb17abd0c6c5bf2635bef76a16323ef091dbd4e41cbb1a5ed10e3ea21fbb5","tier":"starter_2024","role":"editor"}],"comments":[],"custom_thumbnail":true,"trashed":false,"lapsed":null,"subscribed":null,"forks":0,"collection":null,"type":"notebook","body":{"titling":"auto","title":"Projections comparison:","cells":[{"id":0,"value":"# Projections comparison:","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"","database":"$undefined"},{"id":3,"value":"

Mercator VS Equal Earth

","pinned":false,"hidden":false,"mode":"html","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":174,"value":"On the 4th of September 2026, the UN General Assembly voted to encourage governments, schools, international organisations and tech companies to create maps using the Equal Earth projection rather than the Mercator projection.\n\n\nWith the Mercator projection, landmasses appear larger the further they are from the equator. For this reason, it makes Africa look about as large as Greenland, while it actually is 14 times larger.\n\nsource: [news.un.org/en/story/2026/09/1168284](https://news.un.org/en/story/2026/09/1168284)","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":31,"value":"$45","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":112,"value":"---\n\n## Appendix\n\nEdit the *projections* array below, or *red* and *blue* above, to define a new projection.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"","database":"$undefined"},{"id":100,"value":"$46","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":71,"value":"function projectionInput({name = \"\", value} = {}) {\n const form = html`

${name}`;\n form.onchange = () => form.dispatchEvent(new CustomEvent(\"input\"));\n form.oninput = () => form.value = projections[form.i.selectedIndex].value();\n form.oninput();\n return form;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":173,"value":"world = FileAttachment(\"world.json\").json()","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":16,"value":"d3 = require(\"d3-geo@3\", \"d3-geo-projection@4\")","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"}],"files":"$W47","stdlib":"1"}} 44:"$43:body"