2d:null 2e:["$","title",null,{"children":"River Cam Distances | John Walley | Observable"}] 33:T6f8,viewof map = { const line = turf.lineString(data.features[0].geometry.coordinates); const options = {units: 'kilometers'}; const along = turf.along(line, distance, options); const mergedRiverbank = topojson.merge(riverbank, riverbank.objects.riverbank.geometries); const screenCoords = data.features[0].geometry.coordinates.map(d => [projection.scale() * d[0] + projection.translate()[0], -projection.scale() * d[1] + projection.translate()[1]]); const click = event => { pt.x = event.clientX; pt.y = event.clientY; const cursorpt = pt.matrixTransform(svg.getScreenCTM().inverse()); const index = d3.leastIndex(screenCoords.map(d => (cursorpt.x - d[0]) ** 2 + (cursorpt.y - d[1]) ** 2)); mutable pos = data.features[0].geometry.coordinates[index]; } const start = along; const stop = turf.point(pos); const sliced = turf.lineSlice(start, stop, line); const length = turf.length(sliced); const svg = Object.assign(html``, {onclick: click}); const pt = svg.createSVGPoint(); return svg; }34:Td36,landmarks = ({ "type": "FeatureCollection", "generator": "overpass-ide", "copyright": "The data included in this document is from www.openstreetmap.org. The data is made available under ODbL.", "timestamp": "2019-07-24T00:08:03Z", "features": [ { "type": "Feature", "properties": { "@id": "way/13988679", "addr:city": "Cambridge", "addr:country": "GB", "building": "yes", "name": "City of Cambridge Rowing Club", "sport": "rowing", "wikidata": "Q5123615" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 0.1300224, 52.2115208 ], [ 0.1302498, 52.2116975 ], [ 0.1301172, 52.2117615 ], [ 0.1300661, 52.2117218 ], [ 0.1300968, 52.2117069 ], [ 0.1299206, 52.2115699 ], [ 0.1300224, 52.2115208 ] ] ] }, "id": "way/13988679" }, { "type": "Feature", "properties": { "@id": "way/14023442", "addr:city": "Cambridge", "addr:country": "GB", "addr:postcode": "CB4 1GF", "addr:street": "Off Pepys Court", "building": "yes", "name": "Cantabrigian (Cantabs) Rowing Club" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 0.1439916, 52.2152069 ], [ 0.1440332, 52.2152445 ], [ 0.1440929, 52.2152984 ], [ 0.1438256, 52.2154096 ], [ 0.1437243, 52.215318 ], [ 0.1439916, 52.2152069 ] ] ] }, "id": "way/14023442" }, { "type": "Feature", "properties": { "@id": "way/131037276", "addr:city": "Cambridge", "addr:housename": "The White House", "addr:housenumber": "72", "addr:postcode": "CB4 1UN", "addr:street": "Fen Road", "building": "detached", "source": "survey" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 0.1589131, 52.2207329 ], [ 0.1592858, 52.2207951 ], [ 0.159257, 52.2208661 ], [ 0.1590482, 52.2208277 ], [ 0.1590432, 52.220838 ], [ 0.1589586, 52.2208229 ], [ 0.1589512, 52.2208385 ], [ 0.1588698, 52.220824 ], [ 0.1589131, 52.2207329 ] ] ] }, "id": "way/131037276" } ] })35:T1de9,riverbank = ({"type":"Topology","arcs":[[[13072,6228],[-58,-44],[-40,-12],[-82,-40],[-17,-8],[-20,-3],[-27,-11],[-29,-9],[-40,-28],[-25,-5],[-32,-26],[-24,-11],[-15,-11],[-40,-8],[-37,-26],[-34,-25],[-55,-14],[-44,-12],[-76,-47],[-47,-20],[-62,-36],[-32,-25],[-25,-3],[-20,-19],[-46,-20],[-55,-31],[-27,-11],[-22,5],[-15,-22],[-94,-53],[-27,-19],[-89,-40],[-87,-44],[-135,-59],[-75,-26],[-83,-35],[-40,-10],[-13,-14],[-18,-8],[-37,-2],[-43,-9],[-43,-22],[-18,-8],[-54,-15],[-21,-7],[-61,-21],[-35,-3],[-18,-5],[-56,-11],[-12,-10],[-30,-7],[-45,-6],[-16,-14],[-37,-14],[-96,-8],[-89,-20],[-40,0],[-24,-8],[-87,-12],[-17,17],[-20,-3],[-34,-16]],[[10432,5194],[6,135]],[[10438,5329],[43,7],[130,18],[89,17],[102,25],[91,21],[123,33],[154,49],[227,73],[129,39],[69,27],[179,80],[163,87],[153,81],[248,136],[259,136],[126,54],[200,90],[83,37]],[[13006,6339],[66,-111]],[[13519,6989],[3,-47],[2,-68],[-7,-61],[-22,-95],[-25,-68],[-47,-100],[-54,-76],[-25,-34],[-20,-31],[-15,-14],[-14,-6],[-11,-8],[-14,-18],[2,-8],[43,-72],[30,-73],[-3,-14],[-13,9],[-28,-4],[-1,16],[5,23],[-15,34],[-35,27],[-26,10],[-22,-6],[-14,-15],[-23,-5],[-31,-18],[-67,-39]],[[13006,6339],[59,31],[62,37],[52,39],[51,48],[55,58],[29,42],[32,54],[38,64],[22,55],[18,63],[4,65],[-2,89]],[[13426,6984],[93,5]],[[13947,9126],[-38,73]],[[13909,9199],[42,40],[35,33],[34,42],[30,39],[41,63],[35,70],[43,96],[28,80],[34,126],[15,91],[14,92],[1,32]],[[14261,10003],[88,1]],[[14349,10004],[-9,-101],[-9,-71],[2,-74],[-48,-174],[-48,-91],[-38,-90],[-46,-73],[-49,-66],[-67,-67],[-61,-54],[-29,-17]],[[13272,8236],[-91,-24]],[[13181,8212],[-22,88],[-5,62],[1,61],[4,59],[8,69],[18,74],[22,54],[29,53],[31,48],[38,39],[45,34],[55,34]],[[13405,8887],[38,-80]],[[13443,8807],[-60,-53],[-37,-48],[-39,-62],[-30,-55],[-12,-48],[-13,-76],[-4,-51],[6,-79],[18,-99]],[[13426,6984],[-12,102],[-33,162],[-45,239],[-2,10],[-42,241],[-44,181],[-67,293]],[[13272,8236],[20,-84],[40,-121],[20,-124],[13,-58],[17,-46],[6,-18],[5,-56],[3,-51],[39,-197],[38,-219],[16,-85],[20,-104],[10,-84]],[[13405,8887],[23,15],[232,140],[172,111],[77,46]],[[13947,9126],[-40,-25],[-119,-72],[-123,-73],[-136,-82],[-86,-67]],[[10432,5194],[-39,-10],[-18,-4],[-22,5],[-34,-7],[-50,-11],[-7,-2],[-60,-14],[-24,-22],[-77,-39],[-94,-39],[-12,-14],[-82,-34],[-118,-78],[-74,-54],[-94,-78],[13,-15],[-5,-3],[-5,-1],[-9,16],[-7,2],[-14,-10],[-81,-65],[-65,-44],[-108,-79],[-79,-42],[-72,-34],[-81,-33],[-74,-23],[-55,-9],[-27,-5],[-71,-16],[-133,-29],[-121,-50],[-111,-47],[-99,-65],[-99,-67],[-37,-22],[-74,-45],[-86,-42],[-144,-45],[-157,-53],[-173,-56],[-148,-51],[-89,-48],[-56,-38],[-47,-48],[-39,-78],[-40,-179],[-37,-205],[-7,-67],[-22,-238],[-15,-132],[-17,-84],[-35,-84],[-42,-81],[-108,-152],[-6,7],[-22,-24],[-128,-148],[-67,-87],[-52,-81],[-61,-107],[-42,-75],[-69,-157],[-6,-13],[-41,-99],[-30,-79],[-42,-140],[-29,-106],[-35,-107],[-50,-115],[-87,-142],[-88,-133],[-50,-62],[-60,-64],[-55,-50],[-48,-41],[-46,-36],[-45,-28],[-113,-57],[-133,-59],[-64,-23],[-72,-13],[-97,-1],[-85,10],[-86,19],[-80,15],[-37,4],[-42,3],[-71,-2],[-33,-7],[-81,-25],[-40,-13],[-39,-20],[-61,-37],[-39,-35],[-23,-25],[-34,-37],[-31,-36],[-12,-16],[-23,-21],[-27,-27],[-30,-21],[-31,-16],[-58,-24],[-33,-11],[-57,-18],[-73,-15],[-103,-19],[-67,-9],[-33,-2],[-46,-1],[-154,4],[-134,11],[-67,7],[-67,11],[-56,10],[-55,14],[-151,44],[-69,26],[-53,22],[-95,50],[-49,27],[-48,29],[-52,42],[-143,126],[-66,61],[-99,101],[-97,109],[-50,86],[-48,113],[-36,65],[-27,39],[-73,77],[-84,75],[-58,51],[-61,41],[-135,79],[-77,39],[-95,48],[-84,48],[-88,44],[-46,14],[-48,15],[-56,17],[-51,9],[-83,11],[-119,-3],[-173,3],[-56,-3],[-158,-31],[-158,-36],[-156,-53],[-76,-31],[-72,-45],[-78,-36],[-10,5],[-7,1],[-8,-4],[-9,21],[11,6],[8,9],[5,9],[-2,7],[-14,1],[-12,-3],[-9,-3],[-122,-62],[-8,18],[-9,20],[15,9],[5,3],[2,6],[-7,1],[-16,-6],[-10,-4],[-40,18],[16,47],[7,7],[35,11],[126,42],[134,42],[187,53],[156,37],[24,3],[205,33],[40,12],[74,8],[71,11],[64,3],[67,-3],[79,-8],[91,-11],[79,-17],[17,-4],[49,-12],[20,-5],[86,-28],[86,-41],[128,-70],[39,-20],[57,-37],[142,-96],[52,-32],[48,-33],[21,-15],[57,-60],[24,-32],[45,-59],[41,-61],[44,-59],[26,-35],[47,-61],[21,-25],[-11,-20],[31,-46],[38,-51],[53,-60],[75,-88],[81,-77],[86,-75],[106,-91],[8,13],[9,-6],[-6,-14],[72,-49],[64,-35],[55,-25],[116,-46],[66,-23],[118,-28],[22,-6],[0,9],[15,-5],[-1,-6],[86,-18],[75,-12],[89,-12],[47,-4],[43,-1],[84,-1],[86,6],[40,4],[124,13],[99,31],[17,6],[63,31],[27,14],[3,-4],[38,26],[36,30],[32,30],[-4,9],[20,22],[25,16],[72,91],[51,44],[59,41],[64,31],[25,-2],[13,23],[9,14],[18,-6],[26,-9],[30,-6],[40,-1],[93,-11],[113,-13],[92,-9],[64,-13],[48,-2],[138,35],[106,32],[99,39],[17,23],[20,19],[44,23],[40,31],[59,42],[81,64],[44,54],[16,19],[81,118],[81,123],[67,129],[25,89],[49,163],[52,143],[52,145],[28,62],[21,48],[111,204],[92,154],[71,93],[79,92],[27,20],[27,34],[50,64],[71,106],[27,54],[38,115],[4,14],[14,81],[4,22],[2,95],[3,64],[5,102],[9,92],[11,49],[31,145],[8,45],[12,72],[32,87],[13,36],[19,37],[62,85],[86,63],[83,50],[12,-11],[31,15],[15,-17],[30,12],[14,45],[56,9],[91,26],[2,-14],[21,1],[14,3],[6,25],[71,26],[5,-12],[17,-6],[17,15],[2,14],[53,25],[24,-4],[53,23],[123,41],[106,61],[69,51],[69,59],[67,56],[86,53],[79,42],[62,20],[81,11],[74,5],[104,9],[71,14],[79,20],[67,25],[72,33],[91,54],[67,39],[71,53],[77,70],[89,76],[96,78],[52,39],[88,56],[99,51],[104,45],[104,47],[62,30],[83,16],[23,4],[50,12],[24,3],[38,6],[17,3]],[[14261,10003],[3,69],[7,120],[12,168],[14,128],[22,127],[31,142],[55,288],[33,166],[33,185],[13,107],[27,199],[18,132],[7,51],[20,121],[12,95],[5,109],[3,118],[0,95],[-5,87],[5,67],[12,98],[34,137],[33,104],[37,87],[56,101],[55,78],[69,87],[138,182],[192,238],[111,143],[55,61],[32,31],[34,25],[48,30],[3,-9],[5,-7],[-15,-15],[-2,-10],[4,-8],[11,0],[12,6],[18,-34],[3,-4],[-4,-7],[0,-5],[5,-1],[5,0],[-8,-40],[45,-18],[-46,-34],[-32,-23],[-27,20],[-32,-25],[-123,-121],[-97,-107],[-153,-178],[-47,-68],[-98,-124],[-73,-98],[-41,-80],[-29,-87],[-36,-85],[-23,-141],[-4,-21],[-5,-96],[-1,-52],[-8,-118],[-11,-172],[-1,-52],[-29,-194],[-10,-102],[-13,-85],[-18,-129],[-8,-92],[-19,-60],[-27,-165],[-34,-164],[-5,-28],[-22,-56],[-13,-90],[-12,-67],[5,-42],[-17,-50],[-22,-132],[-25,-108],[-8,-60],[-37,-155],[-2,-48],[-7,-56],[-5,-101],[0,-177]]],"transform":{"scale":[0.0000034777370855821123,0.000001876951140997586],"translate":[0.12053220000000002,52.2103268]},"objects":{"riverbank":{"type":"GeometryCollection","geometries":[{"arcs":[[0,1,2,3]],"type":"Polygon","properties":{"@id":"way/148820820","name":"The Reach","natural":"water","water":"river"},"id":"way/148820820"},{"arcs":[[4,-4,5,6]],"type":"Polygon","properties":{"@id":"way/304067408","name":"Ditton Corner","natural":"water","water":"river"},"id":"way/304067408"},{"arcs":[[7,8,9,10]],"type":"Polygon","properties":{"@id":"way/304067410","name":"First Post Corner","natural":"water","water":"river"},"id":"way/304067410"},{"arcs":[[11,12,13,14]],"type":"Polygon","properties":{"@id":"way/304067414","name":"Grassy Corner","natural":"water","water":"river"},"id":"way/304067414"},{"arcs":[[-7,15,-12,16]],"type":"Polygon","properties":{"@id":"way/304067417","name":"Plough Reach","natural":"water","water":"river"},"id":"way/304067417"},{"arcs":[[-14,17,-8,18]],"type":"Polygon","properties":{"@id":"way/304067418","name":"The Gut","natural":"water","water":"river"},"id":"way/304067418"},{"arcs":[[19,-2]],"type":"Polygon","properties":{"@id":"way/304067419","natural":"water","water":"river"},"id":"way/304067419"},{"arcs":[[-10,20]],"type":"Polygon","properties":{"@id":"way/304067420","natural":"water","water":"river"},"id":"way/304067420"}]}}})36:T12d1,data = ({ "type": "FeatureCollection", "generator": "overpass-ide", "copyright": "The data included in this document is from www.openstreetmap.org. The data is made available under ODbL.", "timestamp": "2019-07-23T20:34:02Z", "features": [ { "type": "Feature", "properties": { "@id": "way/144555404", "boat": "yes", "have_riverbank": "yes", "maxspeed": "8", "motorboat": "yes", "name": "River Cam", "waterway": "river", "wikidata": "Q944772", "wikipedia": "en:River Cam" }, "geometry": { "type": "LineString", "coordinates": [ [0.1214399, 52.2130446], [0.1221041, 52.2131547], [0.1229479, 52.2132852], [0.123729, 52.2133646], [0.1242929, 52.2133876], [0.1248526, 52.2133799], [0.125429, 52.2133338], [0.1262486, 52.2131973], [0.126962, 52.2130037], [0.1276972, 52.2127375], [0.1282152, 52.2125225], [0.1286036, 52.2123024], [0.1290046, 52.2119774], [0.1292678, 52.2116958], [0.1295226, 52.211532], [0.1303037, 52.2111046], [0.1308133, 52.2108768], [0.1315526, 52.210672], [0.1321458, 52.2105441], [0.1328016, 52.2104622], [0.1335033, 52.2104085], [0.1341048, 52.2104008], [0.1346813, 52.2104238], [0.1352201, 52.2104622], [0.1356044, 52.2105339], [0.135901, 52.2106285], [0.1363756, 52.2108723], [0.1367869, 52.2110729], [0.1370873, 52.2111609], [0.137505, 52.2112197], [0.1380133, 52.2112231], [0.1387948, 52.2111663], [0.1392078, 52.2111527], [0.139639, 52.2111967], [0.1403788, 52.2113733], [0.1408174, 52.2115141], [0.1414147, 52.2117905], [0.1417155, 52.2119953], [0.1420177, 52.2122637], [0.1422501, 52.2124611], [0.1424005, 52.2126658], [0.142825, 52.2133653], [0.1430912, 52.2137321], [0.1434197, 52.2140889], [0.1439376, 52.2145506], [0.1442906, 52.2147834], [0.1445016, 52.2148976], [0.1448338, 52.215126], [0.1451113, 52.2153547], [0.145306, 52.2156602], [0.1453537, 52.2161415], [0.1454414, 52.21651], [0.1456085, 52.2169937], [0.1457226, 52.2172254], [0.1458459, 52.2173687], [0.14598, 52.2174535], [0.1462608, 52.2175733], [0.1466736, 52.2176796], [0.1487998, 52.2180711], [0.1491799, 52.2181888], [0.1495057, 52.2183117], [0.1499276, 52.218478], [0.1502367, 52.2185829], [0.1507588, 52.2186981], [0.1512516, 52.218751], [0.1518463, 52.2187972], [0.1523539, 52.2188814], [0.1531632, 52.2191161], [0.1540681, 52.2194967], [0.1549139, 52.2198139], [0.1556328, 52.2200175], [0.1560558, 52.2201065], [0.1571723, 52.2202163], [0.1580938, 52.2203003], [0.1594975, 52.2205157], [0.1601572, 52.2206378], [0.1614591, 52.2208971], [0.1623305, 52.2211508], [0.1641991, 52.221692], [0.1658464, 52.2221016], [0.1663518, 52.2222756], [0.1666735, 52.2224112], [0.1669032, 52.2225442], [0.1671622, 52.2227541], [0.1673, 52.2229153], [0.1673794, 52.2230637], [0.1674254, 52.2232377], [0.1674086, 52.2234347], [0.1670653, 52.2244145], [0.1670285, 52.2245196], [0.1665732, 52.2257146], [0.1664479, 52.2260165], [0.1664312, 52.2261777], [0.1664939, 52.2263645], [0.1666108, 52.2266024], [0.1667737, 52.2267329], [0.1670995, 52.226889], [0.1690001, 52.2275235], [0.1693719, 52.2276949], [0.1697017, 52.227958], [0.1700119, 52.2283376], [0.1701613, 52.2286138], [0.1702345, 52.2288447], [0.1702449, 52.2289435], [0.1702736, 52.2294544], [0.1703617, 52.2299238], [0.1706537, 52.230722], [0.1708795, 52.2313511], [0.1711118, 52.2321664], [0.1713309, 52.2329525], [0.1713936, 52.2332978], [0.1713978, 52.2337992], [0.1714771, 52.2342009], [0.1717139, 52.2346485], [0.1719032, 52.2348558], [0.1723418, 52.2351755], [0.1728639, 52.235526], [0.1737578, 52.2360939] ] }, "id": "way/144555404" } ] }) 37:[] 31:{"id":"829030c033e459dc","slug":"river-cam-distances","title":"River Cam Distances","thumbnail":"68df1e0cf113e279067db796f913fe65fdab92bd55c918b57b2eca1e098696ea","access_level":"public","create_time":"$D2019-07-23T20:49:55.390Z","update_time":"$D2020-05-05T20:42:15.226Z","view_time":null,"first_public_time":"$D2019-07-23T21:07:15.833Z","has_unpublished_edits":null,"fork":false,"stars":1,"starred":false,"owner":{"type":"team","id":"a2bd518a57cf099b","login":"johnwalley","name":"John Walley","avatar_url":"https://avatars-next.observableusercontent.com/f698f408dc6d29dba248b2d94e69299456dc94e9f99cd5789f2d54a8a424793f","tier":"starter_2024"},"version":192,"publish_version":192,"role":null,"authored":false,"authors":[{"type":"individual","id":"3ceed7e2e8194435","login":"johnwalley","name":"John Walley","avatar_url":"https://avatars-next.observableusercontent.com/f698f408dc6d29dba248b2d94e69299456dc94e9f99cd5789f2d54a8a424793f","tier":null}],"members":[{"type":"individual","id":"3ceed7e2e8194435","login":"johnwalley","name":"John Walley","avatar_url":"https://avatars-next.observableusercontent.com/f698f408dc6d29dba248b2d94e69299456dc94e9f99cd5789f2d54a8a424793f","tier":null,"role":"editor"}],"comments":[],"custom_thumbnail":false,"trashed":false,"lapsed":null,"subscribed":null,"forks":3,"collection":null,"type":"notebook","body":{"title":"River Cam Distances","cells":[{"id":0,"value":"md`# River Cam Distances`","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":14,"value":"$33","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":43,"value":"viewof distance = html``","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":109,"value":"mutable pos = [0,0]","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":12,"value":"path = d3.geoPath(projection)","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":10,"value":"projection = d3.geoIdentity()\n .reflectY(true)\n .fitWidth(width, data)","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":18,"value":"width = 800","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":20,"value":"height = 400","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":171,"value":"$34","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":149,"value":"$35","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":6,"value":"$36","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":156,"value":"topojson = require(\"topojson-client\")","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":22,"value":"turf = require(\"@turf/turf\")","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":4,"value":"d3 = require(\"d3-geo@1\", \"d3-array@2\")","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"}],"files":"$W37","stdlib":"1","titling":"auto"}} 32:"$31:body"