27:null 28:["$","title",null,{"children":"Scottish Peaks | plebras | Observable"}] 2d:T172e,{ const size = 600; // top level SVG const svg = d3.create('svg') .attr('viewBox', `0 0 ${size} ${size}`) // .attr('width',size).attr('height',size) .style('border','solid 1px #EFEFEF'); // gradients const colorScale = d3.scaleOrdinal(['Munros','Corbetts','Grahams'],['#043e52','#016a6d','#41a87f']); const defs = svg.append('defs'); defs.html(` `) // get transformed data (with interpolated heights) const munros = getPeaksInterpolated('munro', centroidScotland) const corbetts = getPeaksInterpolated('corbett', centroidScotland) const grahams = getPeaksInterpolated('graham', centroidScotland) const peaks = [...munros.filter(d=>d[0]!==null), ...corbetts.filter(d=>d[0]!==null), ...grahams.filter(d=>d[0]!==null)]; // original data // radial plot const plot = svg.append('g').attr('transform',`translate(${size/2},${size/2+20})`); const margin = 20; const decrease = 0.1; // introducing a minor decrease for each sets to differentiate heights further const scaleRMunros = d3.scalePow([0,d3.max(munros, d=>d[1])],[0,size/2-margin]).exponent(0.6); const scaleRCorbetts = d3.scalePow([0,d3.max(munros, d=>d[1])],[0,size/(2+decrease)-margin]).exponent(0.6); const scaleRGrahams = d3.scalePow([0,d3.max(munros, d=>d[1])],[0,size/(2+decrease*2)-margin]).exponent(0.6); const lineGen = d3.radialLine() .angle(d=>d[2]) .curve(d3.curveBasisClosed); // Paths const pathMunro = plot.append('path') .datum(munros) .attr('d', lineGen.radius(d=>scaleRMunros(d[1]))) .style('fill',"url('#munroGradient')") .style('stroke','#ddd') .style('stroke-width',1); const pathCorbett = plot.append('path') .datum(corbetts) .attr('d', lineGen.radius(d=>scaleRCorbetts(d[1]))) .style('fill',"url('#corbettGradient')") .style('stroke','#ddd') .style('stroke-width',1); const pathGraham = plot.append('path') .datum(grahams) .attr('d', lineGen.radius(d=>scaleRGrahams(d[1]))) .style('fill',"url('#grahamGradient')") .style('stroke','#ddd') .style('stroke-width',1); // Map let projection = scotlandProjection.fitSize([size/2,size/2],scotland); let pathGen = d3.geoPath().projection(projection); let cent = projection(centroidScotland); let map = plot.append('g'); map.selectAll('path').data(scotland.features).join('path') .attr('d',pathGen) .attr('fill','#EFEFEF') .attr('stroke','#ddd') .attr('stroke-width',0.5) .attr('transform',`translate(${-cent[0]},${-cent[1]})`); let mapPoints = map.selectAll('circle').data(peaks).join('circle') .attr('cx', d=>projection([d[3],d[4]])[0]-cent[0]) .attr('cy', d=>projection([d[3],d[4]])[1]-cent[1]) .attr('r',1) .style('fill','grey'); mapPoints.append('title') .text(d=>d[0]); // Color Legend if(legend){ const peakLegend = svg.append('g') .attr('transform','translate(10,30)') .style('font-family','system-ui, sans-serif') .style('font-size', '12px') let peakLegendLabel = peakLegend.selectAll('g') .data(colorScale.domain()) .join('g') .attr('transform', (d,i)=>`translate(${i*70},0)`); peakLegendLabel.selectAll('rect') .data(d=>[d]) .join('rect') .attr('fill',d=>colorScale(d)) .attr('width',10) .attr('height',10); peakLegendLabel.selectAll('text') .data(d=>[d]) .join('text') .text(d=>d) .attr('dx',13) .attr('dy',9); // Height legend defs.append('marker') .attr('id', 'arrowhead').attr('viewBox','0 0 10 10').attr('refX',5).attr('refY',5) .attr('markerWidth',6).attr('markerHeight',6).attr('orient','auto-start-reverse') .append('path').attr('d','M 0 0 L 10 5 L 0 10 z').attr('fill','grey'); const heightLegend = svg.append('g') .attr('transform',`translate(${size/2},30)`) .style('font-family','system-ui, sans-serif') .style('font-size', '12px') heightLegend.append('text') .text('Peak height (ft)') .attr('dy',9); heightLegend.append('line') .attr('x1',0) .attr('y1',12) .attr('x2',scaleRMunros(d3.max(munros, d=>d[1]))) .attr('y2',12) .attr('marker-end','url(#arrowhead)') .attr('stroke','grey') .attr('stroke-width',1) .attr('stroke-dasharray','5 5'); // peak labels const peakLabels = ['Ben Nevis [Beinn Nibheis]', 'The Cobbler [Ben Arthur]', 'Ben Lomond', 'Ben Macdui [Beinn Macduibh]', 'Cairn Gorm', 'The Storr', 'Carn Eighe', 'Ben More', 'An Teallach - Bidein a\' Ghlas Thuill', 'Blabheinn [Bla Bheinn]', 'Ben Tirran [The Goet]', 'Farragon Hill'].map(d=>peaks.find(d2=>d2[0]==d)); const labelOffets = [0,0,10,-10,0,0,0,0,0,0,0,0]; const labels = plot.append('g').selectAll('text') .data(peakLabels) .join('text') .text(d=>d[0]) .attr('transform',d=>`rotate(${d[2]*180/Math.PI})translate(0,${-scaleRMunros(d3.max(munros, d=>d[1]))})`) .style('text-anchor','middle') .style('font-family','system-ui, sans-serif') .style('font-size', '8px') .attr('dy', (d,i)=>labelOffets[i]); } return svg.node(); }2e:T61f,{ let width = 400, height = 400; let projection = scotlandProjection.fitSize([width,height],scotland); let pathGen = d3.geoPath().projection(projection); let colour = d3.scaleSequential([0,d3.max(scottish_peaks,d=>d['height (ft)'])],d3.interpolateGreens); const svg = d3.create('svg').attr('width',width).attr('height',height).style('border','solid 1px black'); let back = svg.append('g'); back.selectAll('path').data(scotland.features).join('path') .attr('d',pathGen) .attr('fill','lightgrey'); let points = svg.append('g'); points.selectAll('a').data(scottish_peaks.toSorted((a,b)=>a['height (ft)']-b['height (ft)'])).join('a') .attr('href', d=>d['hill-bagging-url']) .attr('target', '_blank') .attr('fill', 'inherit') .each(function(d){ d3.select(this).append('circle') .attr('transform', d=>`translate(${projection([d.longitude,d.latitude])})`) .attr('fill', d=>colour(d['height (ft)'])) .attr('r', 6) .attr('fill-opacity', 0.7) .attr('stroke', d=>colour(d['height (ft)'])) .attr('stroke-width', 1) .append('title').text(d=>d.name) }) let zoom = d3.zoom() .extent([[0,0], [width,height]]) .translateExtent([[0,0], [width,height]]) .scaleExtent([1,10]) .on('zoom', ({transform})=>{ back.attr('transform', transform); points.attr('transform', transform); points.selectAll('circle') .attr('r', 6/transform.k) .attr('stroke-width', 0.5/transform.k); }) svg.call(zoom) return svg.node(); }2f:T824,OSGB36 = function(lambda, phi){ const Pi = Math.PI, cos = Math.cos, sin = Math.sin, tan = Math.tan, sqrt = Math.sqrt, pow = Math.pow; /** * Adapted from Chris Veness (https://www.movable-type.co.uk/scripts/latlong-os-gridref.html), MIT Licence */ // const phi = lat; // const lambda = lon; // ellipsoid parameters const a = 6377563.396, b = 6356256.909; // true origins const phi0 = 49*Math.PI/180, lambda0 = -2*Math.PI/180; const E0 = 400e3, N0 = -100e3; // scale const F0 = 0.9996012717; let e2 = 1 - (b*b)/(a*a); let n = (a-b)/(a+b), n2 = n*n, n3 = n2*n; let cosPhi = cos(phi), sinPhi = sin(phi); let eSinPhi = 1-e2*sinPhi*sinPhi; let nu = a*F0/sqrt(eSinPhi); let rho = a*F0*(1-e2)/pow(eSinPhi, 1.5); let eta2 = nu/rho-1; let deltaPhi = phi-phi0, sumPhi = phi+phi0; let Ma = (1 + n + (5/4)*n2 + (5/4)*n3) * (deltaPhi); let Mb = (3*n + 3*n2 + (21/8)*n3) * sin(deltaPhi) * cos(sumPhi); let Mc = ((15/8)*n2 + (15/8)*n3) * sin(2*(deltaPhi)) * cos(2*(sumPhi)); let Md = (35/24)*n3 * sin(3*(deltaPhi)) * cos(3*(sumPhi)); // Meridional arc let M = b * F0 * (Ma - Mb + Mc - Md); let cos3Phi = cosPhi*cosPhi*cosPhi; let cos5Phi = cos3Phi*cosPhi*cosPhi; let tanPhi = tan(phi); let tan2Phi = tanPhi*tanPhi; let tan4Phi = tan2Phi*tan2Phi; let I = M + N0; let II = (nu/2)*sinPhi*cosPhi; let III = (nu/24)*sinPhi*cos3Phi*(5-tan2Phi+9*eta2); let IIIA = (nu/720)*sinPhi*cos5Phi*(61-58*tan2Phi+tan4Phi); let IV = nu*cosPhi; let V = (nu/6)*cos3Phi*(nu/rho-tan2Phi); let VI = (nu/120) * cos5Phi * (5 - 18*tan2Phi + tan4Phi + 14*eta2 - 58*tan2Phi*eta2); let deltaLambda = lambda-lambda0; let deltaLambda2 = deltaLambda*deltaLambda, deltaLambda3 = deltaLambda2*deltaLambda, deltaLambda4 = deltaLambda3*deltaLambda, deltaLambda5 = deltaLambda4*deltaLambda, deltaLambda6 = deltaLambda5*deltaLambda; let N = I + II*deltaLambda2 + III*deltaLambda4 + IIIA*deltaLambda6; let E = E0 + IV*deltaLambda + V*deltaLambda3 + VI*deltaLambda5; return [Number(E.toFixed(0)), Number(N.toFixed(0))]; }30:T4d6,// returns all peaks of a certain kind, with interpolated dummy peaks to create valleys getPeaksInterpolated = function(type, centroid, nAngles = 40, defaultHeight = 0){ let data = scottish_peaks.filter(d=>d[type]==1) .map(d=>[d['name'],d['height (ft)'],getAngle(d['longitude'],d['latitude'],centroid),d['longitude'],d['latitude']]); let bins = d3.bin().value(d=>d[2]).thresholds(nAngles)(data); bins.forEach((bin,i)=>{ if(bin.length==0){ // find previous and next bin with values let p = i==0 ? bins.length-1 : i-1; let diffP = 1; while(bins[p].length==0){ p = p==0 ? bins.length-1 : p-1 diffP++; } let n = i==bins.length-1 ? 0 : i+1; let diffN = 1; while(bins[n].length==0){ n = n==bins.length-1 ? 0 : n+1; diffN++; } // get previous and next height let nHeight = bins[n][0][1]; let pHeight = bins[p][bins[p].length-1][1]; // get weighted average let height = diffP>diffN ? ((nHeight*diffP)+(defaultHeight*diffN))/(diffP+diffN) : ((defaultHeight*diffP)+(pHeight*diffN))/(diffP+diffN) ; data.push([null,height,d3.mean([bin.x0,bin.x1]),null,null]) } }) return data.toSorted((a,b)=>b[2]-a[2]); }31:Ta0f,// const types = ['munro','graham','corbett'] displayRadialProjection = function(types, centroid, size=400){ // top level SVG const svg = d3.create('svg') .attr('width',size).attr('height',size) .style('border','solid 1px #EFEFEF'); // get transformed data const data = types.map(d=>getPeaksInterpolated(d, centroid)); // data with added heights const peaks = data.flatMap(d=>d).filter(d=>d[0]!==null); // original data // radial plot const plot = svg.append('g').attr('transform',`translate(${size/2},${size/2})`); const scaleR = d3.scalePow([0,d3.max(peaks, d=>d[1])],[0,size/2-5]).exponent(0.6); const lineGen = d3.radialLine() .angle(d=>d[2]) .radius(d=>scaleR(d[1])) .curve(d3.curveBasisClosed); plot.append('circle').attr('transform','translate(0,0)').attr('r',4).attr('fill','grey'); const radialPoints = plot.selectAll('circle.peak') .data(peaks) .join('circle').classed('peak',true) .attr('cx',d=>d3.pointRadial(d[2],scaleR(d[1]))[0]) .attr('cy',d=>d3.pointRadial(d[2],scaleR(d[1]))[1]) .attr('r',2) .style('fill','#249EA0'); radialPoints.append('title') .text(d=>d[0]); const paths = plot.selectAll('path') .data(data) .join('path') .attr('d', lineGen) .style('fill','none') .style('stroke','#F78104') .style('stroke-width',2) // map let projection = scotlandProjection.fitSize([size/1.5,size/1.5],scotland); let pathGen = d3.geoPath().projection(projection); let cent = projection(centroid); let map = plot.append('g'); map.selectAll('path').data(scotland.features).join('path') .attr('d',pathGen) .attr('fill','lightgrey') .attr('transform',`translate(${-cent[0]},${-cent[1]})`); let mapPoints = map.selectAll('circle').data(peaks).join('circle') .attr('cx', d=>projection([d[3],d[4]])[0]-cent[0]) .attr('cy', d=>projection([d[3],d[4]])[1]-cent[1]) .attr('r',2) .style('fill','grey'); mapPoints.append('title') .text(d=>d[0]) map.append('circle').attr('transform',`translate(${cent})`) .attr('cx', -cent[0]) .attr('cy', -cent[1]) .attr('r',4).attr('fill','red'); // projection lines plot.selectAll('line').data(peaks) .join('line') .attr('x1', d=>projection([d[3],d[4]])[0]-cent[0]) .attr('y1', d=>projection([d[3],d[4]])[1]-cent[1]) .attr('x2', d=>d3.pointRadial(d[2],scaleR(d[1]))[0]) .attr('y2', d=>d3.pointRadial(d[2],scaleR(d[1]))[1]) .style('stroke-width', 0.5) .style('stroke-opacity', 0.5) .style('stroke', '#005F60'); return svg.node(); }32:[{"id":"84151b1945c3501b4375f330723d46e4c1c390269edbf918492faa3a80aa9a3e4b4050dc9602b4cef83bf817c19029397fac7b897c58c2b14d5cb0d1a1561056","href":"https://static.observableusercontent.com/files/84151b1945c3501b4375f330723d46e4c1c390269edbf918492faa3a80aa9a3e4b4050dc9602b4cef83bf817c19029397fac7b897c58c2b14d5cb0d1a1561056","name":"scottish_peaks.csv","type":"text/csv","lastModified":1744475263585.776,"size":182597},{"id":"34e379cb223ee89ac2d5001f0cdd5cd4c97a7854b531baab11d9939ca0f4dc92516845097e234b342a2857cea0b8f4433522d67b09d84fb685e69c47cfcf2a91","href":"https://static.observableusercontent.com/files/34e379cb223ee89ac2d5001f0cdd5cd4c97a7854b531baab11d9939ca0f4dc92516845097e234b342a2857cea0b8f4433522d67b09d84fb685e69c47cfcf2a91","name":"scotland.topojson.json","type":"application/json","lastModified":1744475650731.689,"size":1055305}] 2b:{"id":"5ca210c01f39a334","slug":null,"title":"Scottish Peaks","thumbnail":"737f73112551b00f14ce2375e33d6e9b534298ed552ddef63703c46103a00d58","access_level":"public","create_time":"$D2025-04-12T16:06:21.429Z","update_time":"$D2025-05-21T16:08:57.774Z","view_time":null,"first_public_time":"$D2025-04-18T21:24:48.208Z","has_unpublished_edits":null,"fork":false,"stars":4,"starred":false,"owner":{"type":"team","id":"4dae3b8c1ee6483c","login":"plebras","name":"plebras","avatar_url":"https://avatars-next.observableusercontent.com/38344624a53a2c2e0fa285246cc6e9d131e3e0d593ef2253ea0f04578af0f548","tier":"starter_2024"},"version":973,"publish_version":null,"role":null,"authored":false,"authors":[{"type":"individual","id":"05eac92041a0a439","login":"plebras","name":"Pierre Le Bras","avatar_url":"https://avatars-next.observableusercontent.com/f69a4c5759b08ebf2258757e603df28806ffd7b51f16f30a85791dc35f4fedab","tier":null}],"members":[{"type":"individual","id":"05eac92041a0a439","login":"plebras","name":"Pierre Le Bras","avatar_url":"https://avatars-next.observableusercontent.com/f69a4c5759b08ebf2258757e603df28806ffd7b51f16f30a85791dc35f4fedab","tier":null,"role":"editor"},{"type":"team","id":"4dae3b8c1ee6483c","login":"plebras","name":"plebras","avatar_url":"https://avatars-next.observableusercontent.com/38344624a53a2c2e0fa285246cc6e9d131e3e0d593ef2253ea0f04578af0f548","tier":"starter_2024","role":"viewer"}],"comments":[],"custom_thumbnail":false,"trashed":false,"lapsed":null,"subscribed":null,"forks":0,"collection":null,"type":"notebook","body":{"title":"Scottish Peaks","cells":[{"id":0,"value":"# Scottish Peaks","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":5,"value":"The data was obtained from [The Database of British and Irish Hills](https://www.hills-database.co.uk/). After some filtering and transformation using [OpenRefine](https://openrefine.org/), we obtained this sub list of Scottish Peaks. Subsidiary tops were not counted.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":7,"value":"Scottish peaks are categorised in 5 (overlapping) lists:\n- **Munros** are Scottish hills over 3,000 feet.\n- **Corbetts** are Scottish hills between 2,500 and 3,000 feet, with a relative height of at least 500 feet.\n- **Grahams** are Scottish hills between 2,000 and 2,500 feet, with a relative height of at least 150 metres (492 ft).\n- **Donalds** are hills in the Scottish Lowlands over 2,000 feet.\n- **Marilyns** are hills in the British Isles that have a relative height of at least 150 m, regardless of absolute height.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":955,"value":"viewof legend = Inputs.toggle({label: \"Legend\", value: true})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":732,"value":"$2d","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":192,"value":"## Distribution Map","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":85,"value":"scotlandMap = Plot.plot({\n width: 600,\n height: 600,\n projection: ({width, height}) => scotlandProjection.fitSize([width,height],scotland),\n color: {\n scheme: 'Greens',\n legend: true,\n label: 'Maximum height (ft)'\n },\n marks: [\n Plot.geo(scotland, {fill: 'lightgrey', fillOpacity: 0.6}),\n Plot.hexagon(scottish_peaks, Plot.hexbin({fill:'max', r:'count'}, {x: 'longitude', y: 'latitude', stroke:'black', strokeWidth:0.5, fillOpacity:0.9, binWidth, fill:'height (ft)'})),\n Plot.dot(scottish_peaks, {\n x:'longitude', \n y:'latitude', \n r: 2,\n fill: 'black',\n fillOpacity: 0.2,\n title: 'name',\n href: 'hill-bagging-url',\n target: '_blank',}),\n ]\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":216,"value":"viewof binWidth = Inputs.range([10, 50], {label: \"Bin Size\", step: 5})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":178,"value":"## Zoomable Map\nThe colour scale reflect the elevation of peaks. Click on a dot to learn more about the peak.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":139,"value":"$2e","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":832,"value":"## Radial Projections","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":834,"value":"To construct these plots, I've calculated the Spherical angle between the peak, a centroid and a point north of the centroid.\nI then used the those angles and the height information of the plots to get a radial line representing the height of peaks from the centroid.\nA centroid relative to the peaks means that they should get scatter around the line. A more global centroid (e.g., the centroid of Scotland) let's see the distribution of peaks.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":848,"value":"Using an azymuthal projection would have also found the angles from the centroid point. However, it also places points based on their distance from the centroid, whereas we re interested in the peak elevation here.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":950,"value":"With this display you essentially get a view of *\"if I were to stand in the middle of ${centroidType=='global'?'Scotland':'Scottish mountains'} and look around, where are its peaks and how tall are they?*","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":836,"value":"Drawing the line using just peaks means that the arcs with no peak remains 'flat'. To get around the issue, I've used a binning algorithm to determined which arc had no peak, at regular intervals. For those arcs, I've added dummy peaks with a weighted height average. This results with more pronounced valleys. ","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":693,"value":"viewof centroidType = Inputs.select([\"global\", \"relative\"], {label: \"Centroid type\"})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":593,"value":"### Radial Projection of Munros","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":608,"value":"displayRadialProjection(['munro'], centroidType=='global'?centroidScotland:centroidMunros)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":701,"value":"### Radial Projection of Corbetts","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":679,"value":"displayRadialProjection(['corbett'], centroidType=='global'?centroidScotland:centroidCorbetts)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":597,"value":"### Radial Projection of Grahams","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":595,"value":"displayRadialProjection(['graham'], centroidType=='global'?centroidScotland:centroidGrahams)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":705,"value":"### Radial Projection of Donalds","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":683,"value":"displayRadialProjection(['donald'], centroidType=='global'?centroidScotland:centroidDonalds)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":750,"value":"### Munros, Corbetts and Grahams","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":752,"value":"displayRadialProjection(['munro','graham','corbett'], centroidScotland)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":45,"value":"### Appendix","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":644,"value":"#### Data","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":18,"value":"scottish_peaks = await FileAttachment(\"scottish_peaks.csv\").csv({typed: \"auto\"})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"scottish_peaks","database":"$undefined"},{"id":315,"value":"centroidScotland = d3.geoCentroid(scotland);","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":320,"value":"centroidPeaks = [d3.mean(scottish_peaks, d=>d.longitude),d3.mean(scottish_peaks, d=>d.latitude)]","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":668,"value":"centroidMunros = [d3.mean(scottish_peaks.filter(d=>d.munro==1), d=>d.longitude),d3.mean(scottish_peaks.filter(d=>d.munro==1), d=>d.latitude)]","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":673,"value":"centroidGrahams = [d3.mean(scottish_peaks.filter(d=>d.graham==1), d=>d.longitude),d3.mean(scottish_peaks.filter(d=>d.graham==1), d=>d.latitude)]","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":677,"value":"centroidCorbetts = [d3.mean(scottish_peaks.filter(d=>d.corbett==1), d=>d.longitude),d3.mean(scottish_peaks.filter(d=>d.corbett==1), d=>d.latitude)]","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":681,"value":"centroidDonalds = [d3.mean(scottish_peaks.filter(d=>d.donald==1), d=>d.longitude),d3.mean(scottish_peaks.filter(d=>d.donald==1), d=>d.latitude)]","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":47,"value":"#### TopoJSON data from [Martin Chorley](https://martinjc.github.io/UK-GeoJSON/)","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":52,"value":"scotland = topojson.feature(scotlandTopojson, scotlandTopojson.objects.eer)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":53,"value":"scotlandTopojson = FileAttachment(\"scotland.topojson.json\").json()","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":840,"value":"Turns out the OSGB36 projection was not necessarily needed, since the Albers projection gives decent results with Scotland.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":255,"value":"$2f","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":304,"value":"// scotlandProjection = d3.geoProjection(OSGB36);\nscotlandProjection = d3.geoAlbers().rotate([0,0])","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":656,"value":"#### Functions","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":354,"value":"// returns the geographic angle between a point, a centroid, and a point north of the centroid\ngetAngle = function (lon, lat, centroid, dNorth=20){\n let northernPoint = [centroid[0], centroid[1]+dNorth];\n let dCentroidPoint = d3.geoDistance([lon,lat],centroid),\n dNorthPoint = d3.geoDistance([lon,lat],northernPoint),\n dNorthCentroid = d3.geoDistance(centroid,northernPoint)\n let num = Math.cos(dNorthPoint) - Math.cos(dCentroidPoint) * Math.cos(dNorthCentroid),\n den = Math.sin(dCentroidPoint) * Math.sin(dNorthCentroid);\n let west = lon < centroid[0] ? -1 : 1;\n return west * Math.acos(num/den);\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":337,"value":"$30","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":606,"value":"$31","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":63,"value":"#### Libraries","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":39,"value":"d3 = require('d3','d3-geo-projection')","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":37,"value":"topojson = require('topojson')","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"}],"files":"$W32","stdlib":"1","titling":"auto"}} 2c:"$2b:body"