${tip(f)}

43:["$","title",null,{"children":"#30DayMapChallenge 2026, Day 2: Lines | Xavier Olive | Observable"}] 4b:T3170,scrolly = { // ── Layout ─────────────────────────────────────────────────────── const W = 1000; // strip width, in its own units (scaled to the page width) const panelHeight = 720; const frontPosition = 0.55; // fog edge, as a fraction of the panel height const corridorWidth = 40; // clear corridor along the line (screen px) const fogFade = 300; // soft transition at the fog edge (px) const revealOffset = 20; // a stop appears once the front is this far past it (px) // A north-south strip around the line, in Web Mercator (from above Basel, // so the canton of Jura is not cut off, down past the // southernmost tip of Valais, so nothing is cut at either end) const extent = {type: "MultiPoint", coordinates: [[6.55, 47.66], [8.2, 45.78]]}; const projection = d3.geoMercator().fitWidth(W, extent); const path = d3.geoPath(projection); const H = Math.ceil(path.bounds(extent)[1][1]); const inStrip = (f) => { const [[x0, y0], [x1, y1]] = path.bounds(f); return x1 > 0 && x0 < W && y1 > 0 && y0 < H; }; const byName = new Map(communes.map((f) => [f.properties.name, f])); const at = (name) => path.centroid(byName.get(name)); // Kilometres of line above a given strip y, for the counter const segments = frontier.coordinates .flatMap((line) => d3.pairs(line, (a, b) => ({ y: (projection(a)[1] + projection(b)[1]) / 2, km: d3.geoDistance(a, b) * 6371.0088 }))) .sort((a, b) => a.y - b.y); const cumKm = d3.cumsum(segments, (d) => d.km); const kmAbove = (y) => { const i = d3.bisector((d) => d.y).right(segments, y); return i ? cumKm[i - 1] : 0; }; // ── The strip: communes, lakes, cantons and the line ───────────── const stripes = `rosti-${Math.random().toString(36).slice(2)}`; const fill = (lang) => lang === "German and French" ? `url(#${stripes})` : palette[lang] ?? "none"; const tip = ({properties: p}) => [ `${p.name} (${p.canton})`, p.lang ?? "no residents", ...[["de", "German"], ["fr", "French"]].filter(([k]) => p[k] != null).map(([k, l]) => `${l}: ${p[k]}%`) ].join("\n"); const cantonLabels = cantons .map((f) => ({text: cantonNames[f.id], xy: path.centroid(f)})) .filter(({xy: [x, y]}) => x > 40 && x < W - 40 && y > 40 && y < H - 40); const towns = [ "Basel", "Laufen", "Delémont", "Moutier", "Solothurn", "Biel/Bienne", "Neuchâtel", "Bern", "Murten", "Fribourg", "Thun", "Bulle", "Lausanne", "Montreux", "Saanen", "Sion", "Sierre", "Leuk", "Visp", "Zermatt" ].map((name) => ({name, xy: at(name)})); const map = svg``; // ── Stops along the way, shown as cards once the front passes them ─ const accent = (lang) => lang === "German and French" ? `linear-gradient(${palette.German}, ${palette.French})` : palette[lang]; const stopYs = stops.map((s) => at(s.place)[1]); const stopElements = stops.map((s, i) => html`

${s.title}

${s.text}

`); // ── Fog over the part already travelled, except a corridor along the line const fog = html`

`; const smoothStops = (length, position) => d3.range(0, 1.0001, 0.125).map((t) => { const alpha = 1 - t * t * (3 - 2 * t); // smoothstep, opaque to transparent return `rgba(0,0,0,${alpha.toFixed(3)}) ${position(t * length)}`; }).join(", "); let maskScale; function updateFogMask(scale) { if (scale === maskScale) return; maskScale = scale; const w = W * scale, h = H * scale; const lines = frontier.coordinates .map((line) => ``) .join(""); const corridor = ``; fog.style.maskImage = fog.style.webkitMaskImage = [ `linear-gradient(${smoothStops(fogFade, (d) => `calc(100% - ${fogFade - d}px)`)})`, `url("data:image/svg+xml,${encodeURIComponent(corridor)}")` ].join(", "); fog.style.maskSize = fog.style.webkitMaskSize = `100% 100%, ${w}px ${h}px`; } // ── Inset map, pinned to the bottom right of the panel ───────────── const lw = 220, lh = 142; const lproj = d3.geoMercator().fitExtent([[6, 6], [lw - 6, lh - 6]], country); const lpath = d3.geoPath(lproj); const clipRect = svg``; const latLine = svg``; const counter = html`0`; const bar = html`

`; const locator = html`

${counter}/${Math.round(frontierKm)} km of Röstigraben

${bar}

`; // Scroll hint: a bouncing chevron, hidden once the reader scrolls const hint = html`

Scroll

`; // ── Panel ──────────────────────────────────────────────────────── const stripElement = html`

${map}${fog}${stopElements}

`; const panel = html`

${locator}${hint}

The Röstigraben, north to south

From the French border north of Delémont to the Italian border above Zermatt

${stripElement}

Language regions and shares: BFS, Die Sprachgebiete der Schweiz (2022)

Boundaries: BFS GEOSTAT via swiss-maps (2023)

`; function update() { const scale = stripElement.clientWidth / W; // screen px per strip unit if (!scale) return; // not laid out yet hint.style.opacity = panel.scrollTop > 30 ? 0 : 1; const front = panel.scrollTop + panelHeight * frontPosition - stripElement.offsetTop; // screen px const frontY = front / scale; // strip units updateFogMask(scale); fog.style.height = `${Math.max(0, Math.min(front, H * scale) + fogFade * 0.4)}px`; stopElements.forEach((element, i) => { const visible = stopYs[i] * scale < front - revealOffset; element.style.opacity = visible ? 1 : 0; element.style.transform = `translateY(${visible ? -50 : -30}%)`; }); const km = Math.min(frontierKm, kmAbove(frontY)); counter.textContent = Math.round(km); bar.style.width = `${(km / frontierKm) * 100}%`; const lat = projection.invert([W / 2, Math.max(0, Math.min(H, frontY))])[1]; const y = frontY <= 0 ? 0 : lproj([8, lat])[1]; clipRect.setAttribute("height", Math.max(0, y)); latLine.setAttribute("y1", y); latLine.setAttribute("y2", y); latLine.style.opacity = frontY > 0 && frontY < H ? 1 : 0; } let frame = null; panel.addEventListener("scroll", () => (frame ??= requestAnimationFrame(() => ((frame = null), update()))), {passive: true}); const observer = new ResizeObserver(update); // also fires once attached observer.observe(stripElement); invalidation.then(() => observer.disconnect()); return panel; }4c:Tc0d,map = { // Two-colour stripes for communes that speak both const stripes = `bilingual-${Math.random().toString(36).slice(2)}`; const defs = () => svg``; const legend = [...Object.keys(palette), "German and French"]; return Plot.plot({ width: 1000, // no height: Plot derives it from the projection's aspect ratio projection: {type: "mercator", domain: country, inset: 5}, title: "Röstigraben: where Swiss German turns into Swiss French", subtitle: `BFS language region of every commune. Striped: ${bilingual.length} communes where both German and French are the main language of at least ${threshold}% of residents`, caption: "#30DayMapChallenge 2026, Day 2: Lines. Language data: BFS, Die Sprachgebiete der Schweiz (2022), pooled structural surveys 2016–2020. Boundaries: BFS GEOSTAT via swiss-maps (2023).", color: {legend: true, domain: legend, range: [...Object.values(palette), `url(#${stripes})`]}, marks: [ defs, Plot.geo(communes, { fill: (d) => d.properties.lang, fillOpacity: 0.6, stroke: "var(--plot-background)", strokeWidth: 0.25, clip: "frame" }), Plot.geo(lakes, {fill: "var(--plot-background)", stroke: "currentColor", strokeOpacity: 0.3, strokeWidth: 0.5, clip: "frame"}), Plot.geo(cantonBorders, {stroke: "currentColor", strokeOpacity: 0.55, strokeWidth: 0.8, clip: "frame"}), Plot.geo(country, {stroke: "currentColor", strokeOpacity: 0.7, strokeWidth: 1.2, clip: "frame"}), // The Röstigraben, with a halo so it reads over the stripes Plot.geo(frontier, {stroke: "var(--plot-background)", strokeWidth: 6, strokeLinejoin: "round", clip: "frame"}), Plot.geo(frontier, {stroke: "currentColor", strokeWidth: 2.6, strokeLinejoin: "round", strokeLinecap: "round", clip: "frame"}), // Canton abbreviations Plot.text(cantons, Plot.geoCentroid({ text: (d) => cantonNames[d.id], fontSize: 15, fontWeight: "bold", fill: "currentColor", fillOpacity: 0.3, clip: "frame" })), // A few towns as landmarks Plot.dot(cities, {x: "lon", y: "lat", r: 2.2, fill: "currentColor", stroke: "var(--plot-background)", clip: "frame"}), Plot.text(cities, { x: "lon", y: "lat", text: "name", dy: -9, fontSize: 11, fill: "currentColor", stroke: "var(--plot-background)", strokeWidth: 3, clip: "frame" }), Plot.tip(communes, Plot.pointer(Plot.geoCentroid({ title: (d) => { const p = d.properties; const share = (k, label) => p[k] == null ? [] : [`${label}: ${p[k]}%`]; return [`${p.name} (${p.canton})`, p.lang ?? "no residents", ...share("de", "German"), ...share("fr", "French"), ...share("it", "Italian"), ...share("rm", "Romansh")].join("\n"); } }))) ] }); }4d:T960,// ── Stops along the line, north to south ───────────────────────── // Each card is anchored to the centroid of a commune; lang sets its colour. stops = [ {place: "Ederswiler", lang: "German", side: "left", title: "Ederswiler", text: "The only German-speaking commune of the canton of Jura. In the BFS surveys, every respondent gave German as their main language."}, {place: "Laufen", lang: "German", side: "right", title: "Laufental", text: "German-speaking, it left the canton of Bern for Basel-Landschaft in 1994, once the new canton of Jura had cut it off from Bern."}, {place: "Moutier", lang: "French", side: "left", title: "Moutier", text: "French-speaking, it voted in 2021 to leave Bern and joined the canton of Jura on 1 January 2026. The canton borders here are still those of 2023."}, {place: "Biel/Bienne", lang: "German and French", side: "right", title: "Biel/Bienne", text: "The largest bilingual town in Switzerland: 50% of residents give German as a main language, 42% French."}, {place: "La Neuveville", lang: "French", side: "left", title: "Lake Biel", text: "On the north shore the line falls between two wine villages: La Neuveville is 85% French, Ligerz next door 80% German."}, {place: "Murten", lang: "German", side: "right", title: "Murten/Morat", text: "78% German and 20% French, in the mostly French-speaking canton of Fribourg."}, {place: "Fribourg", lang: "French", side: "left", title: "Fribourg/Freiburg", text: "The capital of a bilingual canton, on the Sarine/Saane: 71% French, 19% German. Düdingen, across the line, is 88% German."}, {place: "Jaun", lang: "German", side: "right", title: "Jaun/Bellegarde", text: "The only German-speaking commune of the Gruyère district."}, {place: "Château-d'Oex", lang: "French", side: "left", title: "Pays-d'Enhaut", text: "Here the language border is also a canton border: Château-d'Œx and Rougemont in Vaud, Saanen and Gstaad in Bern."}, {place: "Sierre", lang: "French", side: "left", title: "Sierre/Siders", text: "In the Rhône valley the line runs between Sierre (77% French) and Salgesch (76% German, 34% French)."}, {place: "Zermatt", lang: "German", side: "right", title: "The Italian border", text: `The line ends in the high Alps, where Anniviers and Evolène meet Zermatt: ${Math.round(frontierKm)} km of commune borders in all.`} ]4e:[{"id":"09ecee8bfe989593fb95b517b6e422e762cb4798869bd229362ae55d16b1ccb360ad3e1a198a1c6639cbdb594bde349633cd4948f401da9b05034f879fe7b931","href":"https://static.observableusercontent.com/files/09ecee8bfe989593fb95b517b6e422e762cb4798869bd229362ae55d16b1ccb360ad3e1a198a1c6639cbdb594bde349633cd4948f401da9b05034f879fe7b931","name":"languages.csv","type":"text/csv","lastModified":1793628092602,"size":65331}] 47:{"id":"6bed4e1343d847be","slug":"30-day-map-challenge-2026-day-2-lines","title":"#30DayMapChallenge 2026, Day 2: Lines","thumbnail":"9651a97a026d7ee98d885e786931ffefb5ac47b6f56e6f9744464bccb9e0f24d","access_level":"public","create_time":"$D2026-11-02T13:41:17.815Z","update_time":"$D2026-11-02T14:23:42.619Z","view_time":null,"first_public_time":"$D2026-11-02T14:03:10.444Z","has_unpublished_edits":null,"fork":false,"stars":2,"starred":false,"owner":{"type":"team","id":"6b95df6ccdd0cd40","login":"xoolive","name":"Xavier Olive","avatar_url":"https://avatars-next.observableusercontent.com/e055a445877c5a8ee2da134a257760536c2d1ee2fcd43f3aaf3f40db54e13733","tier":"starter_2024","bio":"Research scientist. 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I keep an eye on anything that can fly, an ear for fipradio and a foot ready for next trail.","followed_by_you":false,"follows_you":false}],"members":[{"type":"team","id":"6b95df6ccdd0cd40","login":"xoolive","name":"Xavier Olive","avatar_url":"https://avatars-next.observableusercontent.com/e055a445877c5a8ee2da134a257760536c2d1ee2fcd43f3aaf3f40db54e13733","tier":"starter_2024","role":"editor"}],"comments":[],"custom_thumbnail":false,"trashed":false,"lapsed":null,"subscribed":null,"forks":0,"collection":{"id":"a749676c7f0928cb","slug":"30-day-map-challenge","title":"30 day map challenge","owner":{"id":"6b95df6ccdd0cd40","login":"xoolive","name":"Xavier Olive"}},"type":"notebook","body":{"titling":"auto","title":"#30DayMapChallenge 2026, Day 2: Lines","cells":[{"id":1,"value":"# #30DayMapChallenge 2026, Day 2: Lines\n\nSwitzerland has a name for the line between its German- and French-speaking halves: the *Röstigraben*, the rösti ditch, after the fried potatoes the German side is supposed to eat and the French side isn't. In French it's *la barrière de rösti*. It doesn't follow canton borders: it cuts through Bern, Fribourg and Valais, and through a handful of towns that sit on both sides at once.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":21,"value":"$4b","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":20,"value":"Nobody draws it by law either. The federal constitution leaves languages to the cantons, so the Federal Statistical Office (BFS) draws the language regions itself, commune by commune, by relative majority of *main language* (the language you think in and know best). Its latest revision ([*Die Sprachgebiete der Schweiz*, December 2022](https://dam-api.bfs.admin.ch/hub/api/dam/assets/23705034/master)) pools the structural surveys 2016–2020 and lists, for every commune, the share of residents who give German, French, Italian or Romansh as a main language.\n\nThe thick line is the border between communes the BFS puts on the German side and communes it puts on the French side. Colours are the BFS language region of each commune. Stripes mark communes where German *and* French are each the main language of at least the share set below. Since 2010 people can name more than one main language, so in bilingual towns the shares add up to more than 100%: Biel/Bienne is 50% German and 42% French.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":2,"value":"viewof threshold = Inputs.range([5, 50], {step: 1, value: 25, label: \"Bilingual from (%)\"})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":4,"value":"$4c","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":5,"value":"## Living on both sides\n\nThese are the communes where German and French are both the main language of at least the share set by the slider. The two shares only exist for the three cantons that are officially bilingual, Bern, Fribourg and Valais: in Neuchâtel or Solothurn the BFS only reports the majority language, so a commune there can't show up as bilingual. At 25% that's 23 communes: Biel/Bienne and its neighbours around Lake Biel, villages of the Bernese Jura, the shore of Lake Murten, a few villages around Fribourg, and in Valais Salgesch next to Sierre. Fribourg, the capital of a bilingual canton, is 71% French and 19% German: lower the slider to 15% to see it.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":6,"value":"Inputs.table(bilingual, {\n columns: [\"name\", \"canton\", \"region\", \"de\", \"fr\"],\n header: {name: \"Commune\", canton: \"Canton\", region: \"BFS region\", de: \"German %\", fr: \"French %\"},\n sort: \"de\",\n reverse: true\n})","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":7,"value":"// ── Main language shares by commune ──────────────────────────────\n// Parsed from the appendix tables of BFS, \"Die Sprachgebiete der Schweiz\"\n// (27 December 2022): pooled structural surveys 2016–2020, all residents in\n// private households. region = BFS language region (D, F, I, R); de, fr, it,\n// rm = % giving that language as a main language (people may give several).\n// Shares only exist for the languages the BFS tabulates in each canton.\n// Four communes formed on 1 January 2023 (Andelfingen, Neckertal,\n// Herznach-Ueken, Damphreux-Lugnez) got the region of their monolingual\n// predecessors. Three uninhabited areas (Staatswald Galm, two Ticino\n// comunanze) have no region.\nlanguages = FileAttachment(\"languages.csv\").csv({typed: true})","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":8,"value":"// ── Swiss boundaries: country, cantons, communes, lakes ──────────\n// TopoJSON from interactivethings/swiss-maps, built from BFS GEOSTAT\n// (non-commercial use, attribution required), commune state 2023.\nch = fetch(\"https://cdn.jsdelivr.net/npm/swiss-maps@4.7.0/2023/ch-combined.json\").then((r) => r.json())","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":9,"value":"// ── Language of a commune ────────────────────────────────────────\nlanguage = (d) =>\n d.de >= threshold && d.fr >= threshold ? \"German and French\"\n : ({D: \"German\", F: \"French\", I: \"Italian\", R: \"Romansh\"})[d.region]","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":10,"value":"communes = {\n const byId = new Map(languages.map((d) => [d.bfs, d]));\n return topojson.feature(ch, ch.objects.municipalities).features.map((f) => {\n const d = byId.get(f.id) ?? {};\n return {...f, properties: {...d, lang: language(d)}};\n });\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":11,"value":"bilingual = languages.filter((d) => language(d) === \"German and French\")","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":12,"value":"// ── The Röstigraben itself ───────────────────────────────────────\n// Every stretch of commune border with a German-region commune on one side\n// and a French-region commune on the other.\nfrontier = {\n const region = new Map(languages.map((d) => [d.bfs, d.region]));\n return topojson.mesh(ch, ch.objects.municipalities, (a, b) => {\n const pair = new Set([region.get(a.id), region.get(b.id)]);\n return pair.has(\"D\") && pair.has(\"F\");\n });\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":13,"value":"cantons = topojson.feature(ch, ch.objects.cantons).features","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":14,"value":"cantonBorders = topojson.mesh(ch, ch.objects.cantons, (a, b) => a !== b)","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":15,"value":"country = topojson.feature(ch, ch.objects.country)","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":16,"value":"lakes = topojson.feature(ch, ch.objects.lakes)","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":17,"value":"// ── Colours for the four BFS language regions ────────────────────\npalette = ({German: \"#4e79a7\", French: \"#f28e2b\", Italian: \"#59a14f\", Romansh: \"#b07aa1\"})","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":18,"value":"// ── Canton abbreviations by BFS canton number ────────────────────\ncantonNames = ({\n 1: \"ZH\", 2: \"BE\", 3: \"LU\", 4: \"UR\", 5: \"SZ\", 6: \"OW\", 7: \"NW\", 8: \"GL\", 9: \"ZG\",\n 10: \"FR\", 11: \"SO\", 12: \"BS\", 13: \"BL\", 14: \"SH\", 15: \"AR\", 16: \"AI\", 17: \"SG\",\n 18: \"GR\", 19: \"AG\", 20: \"TG\", 21: \"TI\", 22: \"VD\", 23: \"VS\", 24: \"NE\", 25: \"GE\", 26: \"JU\"\n})","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":19,"value":"// ── Towns shown as landmarks ─────────────────────────────────────\ncities = [\n {name: \"Basel\", lon: 7.588, lat: 47.558},\n {name: \"Delémont\", lon: 7.343, lat: 47.364},\n {name: \"Solothurn\", lon: 7.537, lat: 47.208},\n {name: \"Biel/Bienne\", lon: 7.247, lat: 47.137},\n {name: \"Neuchâtel\", lon: 6.931, lat: 46.990},\n {name: \"Bern\", lon: 7.447, lat: 46.948},\n {name: \"Murten/Morat\", lon: 7.118, lat: 46.928},\n {name: \"Fribourg/Freiburg\", lon: 7.161, lat: 46.806},\n {name: \"Thun\", lon: 7.628, lat: 46.758},\n {name: \"Lausanne\", lon: 6.633, lat: 46.520},\n {name: \"Genève\", lon: 6.143, lat: 46.204},\n {name: \"Sion\", lon: 7.359, lat: 46.233},\n {name: \"Sierre/Siders\", lon: 7.534, lat: 46.292},\n {name: \"Brig\", lon: 7.988, lat: 46.316},\n {name: \"Luzern\", lon: 8.310, lat: 47.050},\n {name: \"Zürich\", lon: 8.541, lat: 47.377},\n {name: \"Chur\", lon: 9.532, lat: 46.849},\n {name: \"Lugano\", lon: 8.951, lat: 46.004}\n]","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":22,"value":"$4d","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":23,"value":"// ── Length of the Röstigraben, in km ─────────────────────────────\n// Includes the stretches across Lake Biel and around enclaves.\nfrontierKm = d3.sum(frontier.coordinates, (line) => d3.sum(d3.pairs(line), ([a, b]) => d3.geoDistance(a, b) * 6371.0088))","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"}],"files":"$W4e","stdlib":"2"}} 42:null