41:null 42:["$","title",null,{"children":"Solar Terminator with Dec graticules | Decalendar | Observable"}] 48:T666,# Solar Terminator with Dec graticules The [solar terminator](https://en.wikipedia.org/wiki/Terminator_%28solar%29#:~:text=a%20moving%20line%20that%20divides%20the%20daylit%20side%20and%20the%20dark%20night%20side%20of%20a%20planetary%20body) maps below show where is currently night (blue) and day (unshaded). The vertical lines on the maps are [Dec graticules](/@dec/irc) which separate the 10 [Dec time zones](/@dec/loc) numbered 0 to 9 on the maps. Dec is a [measurement system](https://en.wikipedia.org/wiki/System_of_units_of_measurement#:~:text=a%20collection%20of%20units%20of%20measurement%20and%20rules%20relating%20them%20to%20each%20other) that [I](https://maptv.github.io) created to measure⏳time,📍position,🧭orientation,📐angles, and🔄cycles in [turns](https://en.wikipedia.org/wiki/Turn_%28angle%29#:~:text=a%20unit%20of%20plane%20angle%20measurement%20equal%20to%202%CF%80%C2%A0radians%2C%20360%C2%A0degrees) ([${tex`\tau`}](https://en.wikipedia.org/wiki/Turn_%28angle%29#:~:text=the%20Greek%20letter,to%20one%20turn)) instead of months, weeks, hours, minutes, seconds, and degrees. For time measurement, Dec uses days and years, which are turns of a [celestial body](https://en.wikipedia.org/wiki/Astronomical_object#:~:text=a%20single%2C%20tightly%20bound%2C%20contiguous%20entity) on [its axis](https://en.wikipedia.org/wiki/Axial_tilt#:~:text=the%20imaginary%20line%20that%20passes%20through%20both%20the%20north%20pole%20and%20south%20pole) and around [the point it orbits](https://en.wikipedia.org/wiki/Barycenter_%28astronomy%29#:~:text=the%20point%20about%20which%20the%20bodies%20orbit), respectively.49:Tb93,map = { const context = DOM.context2d(width, height); const path = d3.geoPath(projection.rotate([-153, 0]), context); function fillMesh(f) { context.beginPath(); path(f); context.fillStyle = color(f.properties.zone); context.fill(); } if (!utctoggle) { context.beginPath(); path({type: "Sphere"}); context.fillStyle = colors.ocean; context.fill(); if (dectoggle) { deczones.map((f, i) => { context.beginPath(); path(f); context.fillStyle = hsla10[i]; context.fill(); }) } } if (utctoggle) { zones.map(f => fillMesh(f)) } context.beginPath(); path(land); if (!utctoggle) { context.fillStyle = colors.land; context.fill(); } context.strokeStyle = `#888`; context.stroke(); if (border) { context.beginPath(); path(borders); context.lineWidth = 1.25; context.strokeStyle = `#888`; context.stroke(); } if (utctoggle) { context.beginPath(); path(mesh); context.lineWidth = 1.25; context.strokeStyle = `#aaa`; context.stroke(); } if (dectoggle) { context.beginPath(); path(graticule); context.lineWidth = 1.25; context.strokeStyle = `#000`; context.stroke(); // context.font = "bold 24px serif"; // context.fillStyle = "#000"; // d3.range(-2, 342 + 1, 36).map((x, i) => context.fillText(i, projection([x, 90])[0] - (width < 400) * 4, 40 - (width < 400) * 20)); // context.fillStyle = "#000"; // d3.range(-2, 342 + 1, 36).map((x, i) => context.fillText(i, projection([x, 90])[0] - (width < 400) * 4, 578 - (width < 400) * 281 - (width < 800) * 120)); // context.font = width < 760 ? "12px serif" : "21px serif"; // context.fillStyle = `#000`; // d3.range(-1.5, 342 + 1, 36).map(x => context.fillText(long2zone(x), ...projection([x, 27.5]))); // d3.range(-1.5, 342 + 1, 36).map(x => context.fillText(long2zone(x), ...projection([x, -48]))); // d3.range(-18, 336 + 1, 36).map(x => context.fillText(formatLongitude(x), ...projection([x, 90]))); // d3.range(-18, 336 + 1, 36).map(x => context.fillText(formatLongitude(x), ...projection([x, -90]))); } if (suntoggle) { context.beginPath(); path(night); context.fillStyle = "rgba(0,0,255,0.4)"; context.fill(); context.beginPath(); path.pointRadius(28); path({type: "Point", coordinates: sun}); context.strokeStyle = "#0009"; context.fillStyle = "#ff0b"; context.lineWidth = 1; context.stroke(); context.fill(); context.beginPath(); path.pointRadius(28); path({type: "Point", coordinates: moon}); context.strokeStyle = "#0009"; context.fillStyle = "#999b"; context.lineWidth = 1; context.stroke(); context.fill(); } //context.canvas.style += "stroke:red;" return context.canvas; }4a:T5ca,The maps above show how [Longitude 0](https://en.wikipedia.org/wiki/18th_meridian_west#:~:text=a%20line%20of%20longitude[1]%20that%20extends%20from%20the%20North%20Pole%20across%20the%20Arctic%20Ocean%2C%20Greenland%2C%20Iceland%2C%20the%20Atlantic%20Ocean%2C%20the%20Canary%20Islands%2C%20the%20Southern%20Ocean%2C%20and%20Antarctica%20to%20the%20South%20Pole), the Dec [International Date Line](https://en.wikipedia.org/wiki/International_Date_Line#:~:text=the%20line%20between%20the%20South%20and%20North%20Poles%20that%20is%20the%20boundary%20between%20one%20calendar%20day%20and%20the%20next) and [prime meridian](https://en.wikipedia.org/wiki/Prime_meridian#:~:text=an%20arbitrarily%2Dchosen%20meridian%20%28a%20line%20of%20longitude%29%20in%20a%20geographic%20coordinate%20system%20at%20which%20longitude%20is%20defined%20to%20be%200%C2%B0), cuts across the Atlantic Ocean just West of Africa and marks the start of Zone 0, the leftmost Dec time zone on the map. Dec has 10 time zones which are each 1 deciturn (10% of a turn) wide and are numbered 0 through 9, like the [lines of longitude](https://en.wikipedia.org/wiki/Meridian_%28geography%29#:~:text=words%2C%20it%20is-,a%20line%20of%20longitude,-.%20The%20position%20of) that separate them. For more Dec maps, check out these notebooks: - [Declock](/@dec/loc) - [Decalc](/@dec/alc) - [Decalendar](/@dec/al) - [Decaliper](/@dec/ali) - [Decirc](/@dec/irc) - [The Sun's view of the Earth](/@dec/the-suns-view-of-the-earth)4b:T5bb,// https://observablehq.com/@bayre/svg-swatches function swatches({ colour, swatchRadius = 7.5, swatchPadding = swatchRadius * (2/3), labelFont = "12px sans-serif", labelFormat = x => x, labelPadding = swatchRadius * 1.5, marginLeft = 0 } = {}) { const spacing = colour .domain() .map(d => labelFormat(d)) .map(d => getLabelLength(d, labelFont) + (swatchRadius * 2) + swatchPadding + labelPadding) .map((_, i, g) => d3.cumsum(g)[i] + marginLeft) const width = d3.max(spacing) const height = swatchRadius * 2 + swatchPadding * 2 const svg = d3.create("svg") .attr("id", "swatches") .attr("width", width) .attr("height", height) .attr("viewBox", [0, 0, width, height]) .style("margin-top", "-12px") .style("overflow", "visible") .style("display", "block"); const g = svg .append("g") .attr("transform", `translate(0, ${height / 2})`) .selectAll("g") .data(colour.domain()) .join("g") .attr("transform", (d, i) => `translate(${spacing[i - 1] || marginLeft}, 0)`); g.append("circle") .attr("fill", colour) .attr("stroke", "black") .attr("r", swatchRadius) .attr("cx", swatchRadius) .attr("cy", 0); g.append("text") .attr("x", swatchRadius * 2 + swatchPadding) .attr("y", 0) .attr("dominant-baseline", "central") .style("font", labelFont) .text(d => labelFormat(d)); return svg.node() }4c:T176f,opts = [ { label: "Airocean", value: "Airocean" }, { label: "Airy’s minimum error", value: "Airy’s minimum error" }, { label: "Aitoff", value: "Aitoff" }, { label: "American polyconic", value: "American polyconic" }, { label: "Armadillo", value: "Armadillo" }, { label: "August", value: "August" }, { label: "azimuthal equal-area", value: "azimuthal equal-area" }, { label: "azimuthal equidistant", value: "azimuthal equidistant" }, { label: "Baker dinomic", value: "Baker dinomic" }, { label: "Berghaus’ star", value: "Berghaus’ star" }, { label: "Bertin’s 1953", value: "Bertin’s 1953" }, { label: "Boggs’ eumorphic", value: "Boggs’ eumorphic" }, { label: "Boggs’ eumorphic (interrupted)", value: "Boggs’ eumorphic (interrupted)" }, { label: "Bonne", value: "Bonne" }, { label: "Bottomley", value: "Bottomley" }, { label: "Bromley", value: "Bromley" }, { label: "Butterfly (gnomonic)", value: "Butterfly (gnomonic)" }, { label: "Butterfly (Collignon)", value: "Butterfly (Collignon)" }, { label: "Butterfly (Waterman)", value: "Butterfly (Waterman)" }, { label: "Cahill-Keyes", value: "Cahill-Keyes" }, { label: "Collignon", value: "Collignon" }, { label: "conic equal-area", value: "conic equal-area" }, { label: "conic equidistant", value: "conic equidistant" }, { label: "Craig retroazimuthal", value: "Craig retroazimuthal" }, { label: "Craster parabolic", value: "Craster parabolic" }, { label: "Cox", value: "Cox" }, { label: "cubic", value: "cubic" }, { label: "cylindrical equal-area", value: "cylindrical equal-area" }, { label: "cylindrical stereographic", value: "cylindrical stereographic" }, { label: "dodecahedral", value: "dodecahedral" }, { label: "Eckert I", value: "Eckert I" }, { label: "Eckert II", value: "Eckert II" }, { label: "Eckert III", value: "Eckert III" }, { label: "Eckert IV", value: "Eckert IV" }, { label: "Eckert V", value: "Eckert V" }, { label: "Eckert VI", value: "Eckert VI" }, { label: "Eisenlohr conformal", value: "Eisenlohr conformal" }, { label: "Equal Earth", value: "Equal Earth" }, { label: "Equirectangular (plate carrée)", value: "Equirectangular (plate carrée)" }, { label: "Fahey pseudocylindrical", value: "Fahey pseudocylindrical" }, { label: "flat-polar parabolic", value: "flat-polar parabolic" }, { label: "flat-polar quartic", value: "flat-polar quartic" }, { label: "flat-polar sinusoidal", value: "flat-polar sinusoidal" }, { label: "Foucaut’s stereographic equivalent", value: "Foucaut’s stereographic equivalent" }, { label: "Foucaut’s sinusoidal", value: "Foucaut’s sinusoidal" }, { label: "general perspective", value: "general perspective" }, { label: "Gingery", value: "Gingery" }, { label: "Ginzburg V", value: "Ginzburg V" }, { label: "Ginzburg VI", value: "Ginzburg VI" }, { label: "Ginzburg VIII", value: "Ginzburg VIII" }, { label: "Ginzburg IX", value: "Ginzburg IX" }, { label: "Goode’s homolosine", value: "Goode’s homolosine" }, { label: "Goode’s homolosine (interrupted)", value: "Goode’s homolosine (interrupted)" }, { label: "gnomonic", value: "gnomonic" }, { label: "Gringorten square", value: "Gringorten square" }, { label: "Gringorten quincuncial", value: "Gringorten quincuncial" }, { label: "Guyou square", value: "Guyou square" }, { label: "Hammer", value: "Hammer" }, { label: "Hammer retroazimuthal", value: "Hammer retroazimuthal" }, { label: "HEALPix", value: "HEALPix" }, { label: "Hill eucyclic", value: "Hill eucyclic" }, { label: "Hufnagel pseudocylindrical", value: "Hufnagel pseudocylindrical" }, { label: "icosahedral", value: "icosahedral" }, { label: "Imago", value: "Imago" }, { label: "Kavrayskiy VII", value: "Kavrayskiy VII" }, { label: "Lagrange conformal", value: "Lagrange conformal" }, { label: "Larrivée", value: "Larrivée" }, { label: "Laskowski tri-optimal", value: "Laskowski tri-optimal" }, { label: "Loximuthal", value: "Loximuthal" }, { label: "Mercator", value: "Mercator" }, { label: "Miller cylindrical", value: "Miller cylindrical" }, { label: "Mollweide", value: "Mollweide" }, { label: "Mollweide (Goode’s interrupted)", value: "Mollweide (Goode’s interrupted)" }, { label: "Mollweide (interrupted hemispheres)", value: "Mollweide (interrupted hemispheres)" }, { label: "Natural Earth", value: "Natural Earth" }, { label: "Natural Earth II", value: "Natural Earth II" }, { label: "Nell–Hammer", value: "Nell–Hammer" }, { label: "Nicolosi globular", value: "Nicolosi globular" }, { label: "orthographic", value: "orthographic" }, { label: "Patterson cylindrical", value: "Patterson cylindrical" }, { label: "Peirce quincuncial", value: "Peirce quincuncial" }, { label: "rectangular polyconic", value: "rectangular polyconic" }, { label: "Robinson", value: "Robinson" }, { label: "sinusoidal", value: "sinusoidal" }, { label: "sinusoidal (interrupted)", value: "sinusoidal (interrupted)" }, { label: "sinu-Mollweide", value: "sinu-Mollweide" }, { label: "sinu-Mollweide (interrupted)", value: "sinu-Mollweide (interrupted)" }, { label: "stereographic", value: "stereographic" }, { label: "Lee’s tetrahedal", value: "Lee’s tetrahedal" }, { label: "Times", value: "Times" }, { label: "Tobler hyperelliptical", value: "Tobler hyperelliptical" }, { label: "transverse Mercator", value: "transverse Mercator" }, { label: "Van der Grinten", value: "Van der Grinten" }, { label: "Van der Grinten II", value: "Van der Grinten II" }, { label: "Van der Grinten III", value: "Van der Grinten III" }, { label: "Van der Grinten IV", value: "Van der Grinten IV" }, { label: "Wagner IV", value: "Wagner IV" }, { label: "Wagner VI", value: "Wagner VI" }, { label: "Wagner VII", value: "Wagner VII" }, { label: "Werner", value: "Werner"}, { label: "Wiechel", value: "Wiechel"}, { label: "Winkel tripel", value: "Winkel tripel"} ]4d:Teba,// https://observablehq.com/@enjalot/draggable-world-map-coordinates-input function worldMapCoordinates(config = {}, dimensions) { const { value = [], title, description, width = dimensions[0] } = Array.isArray(config) ? {value: config} : config; const height = dimensions[1]; let [lon, lat] = value; lon = lon != null ? lon : null; lat = lat != null ? lat : null; const formEl = html``; const context = DOM.context2d(width, height); const canvas = context.canvas; canvas.style.margin = `-6px 0 ${width > 400 ? -12 : -18}px`; const projection = config[2] .precision(0.1) .fitSize([width, height], { type: "Sphere" }).rotate([-153, 0]); const path = d3.geoPath(projection, context).pointRadius(2.5); formEl.append(canvas); function fillMesh(f) { context.beginPath(); path(f); context.fillStyle = color(f.properties.zone); context.fill(); } // function formatLongitude(x) { return `${(x + 18) / 36}`; } function draw() { context.fillStyle = "#fff"; context.fillRect(0, 0, width, height); if (!utctoggle) { context.beginPath(); path({type: "Sphere"}); context.fillStyle = colors.ocean; context.fill(); if (dectoggle) { deczones.map((f, i) => { context.beginPath(); path(f); context.fillStyle = hsla10[i]; context.fill(); }) } } if (utctoggle) { zones.map(f => fillMesh(f)) } context.beginPath(); path(land); if (!utctoggle) { context.fillStyle = colors.land; context.fill(); } context.strokeStyle = `#888`; context.stroke(); if (border) { context.beginPath(); path(borders); context.lineWidth = 1.25; context.strokeStyle = `#888`; context.stroke(); } if (utctoggle) { context.beginPath(); path(mesh); context.lineWidth = 1.25; context.strokeStyle = `#aaa`; context.stroke(); } if (dectoggle) { context.beginPath(); path(graticule); context.lineWidth = 1.25; context.strokeStyle = `#000`; context.stroke(); // context.font = "bold 24px serif"; // context.fillStyle = "#000"; // d3.range(-2, 342 + 1, 36).map((x, i) => context.fillText(i, projection([x, 90])[0] - (width < 400) * 4, 40 - (width < 400) * 20)); // context.fillStyle = "#000"; // d3.range(-2, 342 + 1, 36).map((x, i) => context.fillText(i, projection([x, 90])[0] - (width < 400) * 4, 578 - (width < 400) * 281 - (width < 800) * 120)); // context.font = width < 760 ? "12px serif" : "21px serif"; // context.fillStyle = `#000`; // d3.range(-1.5, 342 + 1, 36).map(x => context.fillText(long2zone(x), ...projection([x, 27.5]))); // d3.range(-1.5, 342 + 1, 36).map(x => context.fillText(long2zone(x), ...projection([x, -48]))); // d3.range(-18, 336 + 1, 36).map(x => context.fillText(formatLongitude(x), ...projection([x, 90]))); // d3.range(-18, 336 + 1, 36).map(x => context.fillText(formatLongitude(x), ...projection([x, -90]))); } if (suntoggle) { context.beginPath(); path(night); context.fillStyle = "rgba(0,0,255,0.4)"; context.fill(); context.beginPath(); path.pointRadius(28); path({type: "Point", coordinates: sun}); context.strokeStyle = "#0009"; context.fillStyle = "#ff0b"; context.lineWidth = 1; context.stroke(); context.fill(); context.beginPath(); path.pointRadius(28); path({type: "Point", coordinates: moon}); context.strokeStyle = "#0009"; context.fillStyle = "#999b"; context.lineWidth = 1; context.stroke(); context.fill(); } } draw(); return formEl; }4e:T4f1,projections = [ {name: "CylindricalEqualArea", value: d3.geoCylindricalEqualArea}, {name: "CylindricalStereographic", value: d3.geoCylindricalStereographic}, {name: "Eckert1", value: d3.geoEckert1}, {name: "Eckert2", value: d3.geoEckert2}, {name: "Eckert3", value: d3.geoEckert3}, {name: "Eckert4", value: d3.geoEckert4}, {name: "Eckert5", value: d3.geoEckert5}, {name: "Eckert6", value: d3.geoEckert6}, {name: "Equirectangular", value: d3.geoEquirectangular}, {name: "Hufnagel", value: d3.geoHufnagel}, {name: "Kavrayskiy7", value: d3.geoKavrayskiy7}, {name: "Miller", value: d3.geoMiller}, {name: "MtFlatPolarParabolic", value: d3.geoMtFlatPolarParabolic}, {name: "MtFlatPolarQuartic", value: d3.geoMtFlatPolarQuartic}, {name: "MtFlatPolarSinusodial", value: d3.geoMtFlatPolarSinusoidal}, {name: "NaturalEarth1", value: d3.geoNaturalEarth1}, {name: "NaturalEarth2", value: d3.geoNaturalEarth2}, {name: "NellHammer", value: d3.geoNellHammer}, {name: "Patterson", value: d3.geoPatterson}, {name: "Robinson", value: d3.geoRobinson}, {name: "Times", value: d3.geoTimes}, {name: "Wagner4", value: d3.geoWagner4}, {name: "Wagner6", value: d3.geoWagner6}, {name: "Winkel3", value: d3.geoWinkel3}, ]4f:T18f5,// https://observablehq.com/@fil/d3-projections proj = [ { name: "Airocean", value: d3.geoAirocean }, { name: "Airy’s minimum error", value: d3.geoAiry }, { name: "Aitoff", value: d3.geoAitoff }, { name: "American polyconic", value: d3.geoPolyconic }, { name: "Armadillo", value: d3.geoArmadillo, options: { clip: { type: "Sphere" } } }, { 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, options: { clip: { type: "Sphere" } } }, { name: "Bertin’s 1953", value: d3.geoBertin1953 }, { name: "Boggs’ eumorphic", value: d3.geoBoggs }, { name: "Boggs’ eumorphic (interrupted)", value: d3.geoInterruptedBoggs, options: { clip: { type: "Sphere" } } }, { 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: "Cahill-Keyes", value: d3.geoCahillKeyes }, { name: "Collignon", value: d3.geoCollignon }, { 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: "Cox", value: d3.geoCox }, { name: "cubic", value: d3.geoCubic }, { name: "cylindrical equal-area", value: d3.geoCylindricalEqualArea }, { name: "cylindrical stereographic", value: d3.geoCylindricalStereographic }, { name: "dodecahedral", value: d3.geoDodecahedral }, { 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: "Gingery", value: d3.geoGingery, options: { clip: { type: "Sphere" } } }, { 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, options: { clip: { type: "Sphere" } } }, { 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, options: { clip: { type: "Sphere" } } }, { name: "HEALPix", value: d3.geoHealpix, options: { clip: { type: "Sphere" } } }, { name: "Hill eucyclic", value: d3.geoHill }, { name: "Hufnagel pseudocylindrical", value: d3.geoHufnagel }, { name: "icosahedral", value: d3.geoIcosahedral }, { name: "Imago", value: d3.geoImago }, { 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: "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, options: { clip: { type: "Sphere" } } }, { name: "Mollweide (interrupted hemispheres)", value: d3.geoInterruptedMollweideHemispheres, options: { clip: { type: "Sphere" } } }, { 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, options: { clip: { type: "Sphere" } } }, { name: "sinu-Mollweide", value: d3.geoSinuMollweide }, { name: "sinu-Mollweide (interrupted)", value: d3.geoInterruptedSinuMollweide, options: { clip: { type: "Sphere" } } }, { name: "stereographic", value: d3.geoStereographic }, { name: "Lee’s tetrahedal", value: d3.geoTetrahedralLee }, { 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 ? () => d3.geoBonne().parallel(90) : null }, { name: "Wiechel", value: d3.geoWiechel }, { name: "Winkel tripel", value: d3.geoWinkel3 } ]50:T7e2,moon = { const now = new Date(); // Julian Date const jd = now.getTime() / 86400000 + 2440587.5; const T = (jd - 2451545.0) / 36525; const rad = Math.PI / 180; const deg = 180 / Math.PI; const norm = x => ((x % 360) + 360) % 360; // Moon's mean elements (degrees) const L0 = norm(218.3164477 + 481267.88123421 * T); const D = norm(297.8501921 + 445267.1114034 * T); const M = norm(357.5291092 + 35999.0502909 * T); const Mp = norm(134.9633964 + 477198.8675055 * T); const F = norm(93.2720950 + 483202.0175233 * T); // Truncated lunar theory (degrees) const lon = L0 + 6.289 * Math.sin(Mp * rad) + 1.274 * Math.sin((2 * D - Mp) * rad) + 0.658 * Math.sin((2 * D) * rad) + 0.214 * Math.sin((2 * Mp) * rad) - 0.186 * Math.sin(M * rad) - 0.059 * Math.sin((2 * D - 2 * Mp) * rad) - 0.057 * Math.sin((2 * D - M - Mp) * rad) + 0.053 * Math.sin((2 * D + Mp) * rad) + 0.046 * Math.sin((2 * D - M) * rad); const lat = 5.128 * Math.sin(F * rad) + 0.280 * Math.sin((Mp + F) * rad) + 0.277 * Math.sin((Mp - F) * rad) + 0.173 * Math.sin((2 * D - F) * rad) + 0.055 * Math.sin((2 * D + F - Mp) * rad) + 0.046 * Math.sin((2 * D - F - Mp) * rad) + 0.033 * Math.sin((2 * D + F) * rad) + 0.017 * Math.sin((2 * Mp + F) * rad); // True obliquity (degrees) const eps = 23.439291 - 0.0130042 * T; // Ecliptic -> Equatorial const λ = lon * rad; const β = lat * rad; const ε = eps * rad; const α = Math.atan2( Math.sin(λ) * Math.cos(ε) - Math.tan(β) * Math.sin(ε), Math.cos(λ) ) * deg; const δ = Math.asin( Math.sin(β) * Math.cos(ε) + Math.cos(β) * Math.sin(ε) * Math.sin(λ) ) * deg; // Greenwich Mean Sidereal Time (degrees) const θ = norm( 280.46061837 + 360.98564736629 * (jd - 2451545.0) + 0.000387933 * T * T - T * T * T / 38710000 ); let longitude = norm(α - θ); if (longitude > 180) longitude -= 360; return [longitude, δ]; 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https://observablehq.com/@mbostock/autosize-svg\ngetLabelLength = (label, labelFont = \"12px sans-serif\") => {\n const id = DOM.uid(\"label\").id;\n const svg = html``;\n\n // Add the SVG element to the DOM so we can determine its size.\n document.body.appendChild(svg);\n\n // Compute the bounding box of the content.\n const width = svg.getElementById(id).getBBox().width;\n\n // Remove the SVG element from the DOM.\n document.body.removeChild(svg);\n\n return width;\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":1161,"value":"timezones = 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10**e;\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":573,"value":"function long2zone(degrees = -180) {\n return Math.floor(long2turn(degrees, 1));\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":16,"value":"projection = select.value().rotate([-148, 0])","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":67,"value":"sun = {\n const now = new Date;\n const day = new Date(+now).setUTCHours(0, 0, 0, 0);\n const t = solar.century(now);\n const longitude = (day - now) / 864e5 * 360 - 180;\n return [longitude - solar.equationOfTime(t) / 4, solar.declination(t)];\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":1329,"value":"$50","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":78,"value":"night = d3.geoCircle()\n .radius(90)\n .center(antipode(sun))\n ()","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":73,"value":"antipode = ([longitude, latitude]) => [longitude + 180, 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require(\"topojson-client@3\")","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":62,"value":"solar = require(\"solar-calculator@0.3/dist/solar-calculator.min.js\")","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":256,"value":"borders = topojson.mesh(countries, countries.objects.countries, (a, b) => a !== b)","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","tool":"$undefined","providerMetadata":"$undefined","attachments":"$undefined","output":"$undefined","database":"$undefined"},{"id":262,"value":"countries = fetch(\"https://cdn.jsdelivr.net/npm/world-atlas@2/countries-50m.json\").then(response => 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