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Equidistant map perimeter circles
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boundary.topojson
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dist.css
.buttons {
margin: 0 auto;
text-align: center;
}
.map svg {
display: block;
margin: 0 auto;
}
.map svg circle {
fill: #008000;
fill-opacity: 0.25;
stroke: #008000;
}
Raw
dist.js
var margin={top:10,right:10,bottom:10,left:10};d3.json("./boundary.topojson",function(t){var e=topojson.feature(t,t.objects.boundary),n=(d3.geoBounds(e),d3.geoCentroid(e),d3.geoAlbers()),r=d3.geoPath().projection(n),a=r.bounds(e),o=(a[1][0]-a[0][0])/(a[1][1]-a[0][1]),i=460,c=i*o,u=c-margin.left-margin.right,l=i-margin.top-margin.bottom,d=d3.select(".map svg").attrs({width:c,height:i}).append("g").attr("transform","rotate(45) translate("+100+", "+-170+")");n.fitSize([u,l],e);var s=_(e.features).map("geometry").flatten().map("coordinates").flatten().sortBy("length").map(function(t){return turf.lineString(t)}).value(),f=_(s).map(function(t){return turf.lineDistance(t)}).sum(),m=1e3,g=m,p=_(s).map(function(t){var e=turf.lineDistance(t),n=Math.ceil(e*m/f),r=Math.min(g,n);g-=r;var a=e/r,o=d3.range(r).map(function(e){return turf.along(t,e*a)});return o}).flatten().map(function(t){return n(t.geometry.coordinates)}).value(),v=function(){var t=d.selectAll("circle").data(p);t.enter().append("circle").attrs({cx:u/2,cy:l/2,r:0}).transition("enter").duration(1e3).delay(function(t,e){return 10*e}).attrs({cx:function(t){return t[0]},cy:function(t){return t[1]},r:1})},y=function(){var t=d.selectAll("circle").data(p);t.transition("exit").duration(250).delay(function(t,e){return 2*e}).attrs({cx:u/2,cy:l/2,r:0}).remove()};v(),document.querySelector("button.enter").addEventListener("click",v),document.querySelector("button.exit").addEventListener("click",y)});
//# sourceMappingURL=data:application/json;charset=utf8;base64,{"version":3,"sources":["script.js"],"names":["const","margin","top","right","bottom","left","d3","json","feature","topojson","objects","boundary","projection","geoBounds","geoCentroid","geoAlbers","path","geoPath","b","bounds","aspect","outerHeight","outerWidth","width","height","g","select","attrs","append","attr","fitSize","lineStrings","_","features","map","flatten","sortBy","d","turf","lineString","value","totalLength","lineDistance","sum","pointsCount","pointsRemaining","points","line","lineLength","upperCount","Math","ceil","linePointsCount","min","step","linePoints","range","along","geometry","coordinates","enter","circles","selectAll","data","cx","cy","r","transition","duration","delay","i","exit","remove","document","querySelector","addEventListener"],"mappings":"AACAA,GAAMC,SAAWC,IAAO,GAAEC,MAAS,GAAEC,OAAU,GAAEC,KAAQ,GAGzDC,IAAGC,KAAK,sBAAuB,SAAAA,GAE9BP,GAAMQ,GAAUC,SAASD,QAAQD,EAAMA,EAAKG,QAAQC,UAW9CC,GARWN,GAACO,UAAUL,GACTF,GAACQ,YAAYN,GAOXF,GAACS,aAGhBC,EAASV,GAACW,UAAUL,WAAWA,GAG9BM,EAAGF,EAAKG,OAAOX,GAGhBY,GAAYF,EAAE,GAAG,GAAKA,EAAE,GAAG,KAAOA,EAAE,GAAG,GAAKA,EAAE,GAAG,IAEjDG,EAAc,IACdC,EAAaD,EAAcD,EAE3BG,EAAQD,EAAarB,OAAOI,KAAOJ,OAAOE,MAC1CqB,EAASH,EAAcpB,OAAOC,IAAMD,OAAOG,OAG1CqB,EAAKnB,GAACoB,OAAO,YACjBC,OAAQJ,MAAOD,EAAYE,OAAQH,IACpCO,OAAO,KACNC,KAAK,YAAa,aAAW5B,OAAS,KAAA,KAAIA,OAAG,IAAA,IAGhDW,GAAWkB,SAASP,EAAOC,GAAShB,EAGpCR,IAAM+B,GAAgBC,EAAAxB,EAAQyB,UAC5BC,IAAI,YACJC,UACAD,IAAI,eACJC,UACAC,OAAO,UACPF,IAAI,SAAAG,GAAA,MAAAC,MAAAC,WAAEF,KACNG,QAGIC,EAAgBT,EAAAD,GACpBG,IAAI,SAAAG,GAAA,MAAAC,MAAAI,aAAKL,KACTM,MAGIC,EAAc,IAChBC,EAAkBD,EAEhBE,EAAWd,EAAAD,GACfG,IAAI,SAAAa,GAKJ/C,GAAMgD,GAAaV,KAAKI,aAAaK,GAG/BE,EAAaC,KAAKC,KAAKH,EAAaJ,EAAcH,GAGlDW,EAAkBF,KAAKG,IAAIR,EAAiBI,EAGlDJ,IAAmBO,CAInBpD,IAAMsD,GAAON,EAAaI,EAEpBG,EAAejD,GAACkD,MAAMJ,GAC1BlB,IAAI,SAAAG,GAAA,MAAAC,MAAAmB,MAAEV,EAAGV,EAAIiB,IAEf,OAAOC,KAGPpB,UACAD,IAAI,SAAAG,GAAA,MAAAzB,GAAEyB,EAAAqB,SAAGC,eACTnB,QAGIoB,EAAQ,WAGb5D,GAAM6D,GAAYpC,EAAAqC,UAAU,UACzBC,KAAKjB,EAGRe,GAAQD,QAAQhC,OAAO,UACpBD,OACAqC,GAAIzC,EAAM,EACV0C,GAAIzC,EAAO,EACX0C,EAAG,IAEJC,WAAW,SACVC,SAAS,KACTC,MAAM,SAAAhC,EAAAiC,GAAA,MAAK,IAAJA,IACP3C,OACAqC,GAAI,SAAA3B,GAAA,MAAAA,GAAA,IACJ4B,GAAI,SAAA5B,GAAA,MAAAA,GAAA,IACJ6B,EAAG,KAMDK,EAAO,WAGZvE,GAAM6D,GAAYpC,EAAAqC,UAAU,UACzBC,KAAKjB,EAGRe,GACEM,WAAW,QACVC,SAAS,KACTC,MAAM,SAAAhC,EAAAiC,GAAA,MAAK,GAAJA,IACP3C,OACAqC,GAAIzC,EAAM,EACV0C,GAAIzC,EAAO,EACX0C,EAAG,IAEJM,SAKHZ,KAGAa,SAASC,cAAc,gBAAgBC,iBAAiB,QAASf,GACjEa,SAASC,cAAc,eAAeC,iBAAiB,QAASJ","file":"script.js","sourcesContent":["// Setup chart dimensions.\nconst margin = { top: 10, right: 10, bottom: 10, left: 10 }\n\n// Get GeoJSON.\nd3.json('./boundary.topojson', json => {\n\n\tconst feature = topojson.feature(json, json.objects.boundary)\n\n\t// Get feature's bounds and centroid.\n\tconst bounds = d3.geoBounds(feature)\n\tconst centroid = d3.geoCentroid(feature)\n\n\t// const projection = d3.geoConicConformal()\n\t// \t.parallels([bounds[0][1], bounds[1][1]])\n\t// \t.rotate([-centroid[0], 0])\n\t// \t.center([0, -centroid[1]])\n\n\tconst projection = d3.geoAlbers()\n\n\t// Get the path.\n\tconst path = d3.geoPath().projection(projection)\n\n\t// Get the path's bounds (i.e., in pixels).\n\tconst b = path.bounds(feature)\n\n\t// Get aspect ratio.\n\tconst aspect = (b[1][0] - b[0][0]) / (b[1][1] - b[0][1])\n\n\tconst outerHeight = 460\n\tconst outerWidth = outerHeight * aspect\n\n\tconst width = outerWidth - margin.left - margin.right\n\tconst height = outerHeight - margin.top - margin.bottom\n\n\t// Prepare svg.\n\tconst g = d3.select('.map svg')\n\t\t\t.attrs({ width: outerWidth, height: outerHeight })\n\t\t.append('g')\n\t\t\t.attr('transform', `translate(${margin.left}, ${margin.top})`)\n\n\t// Fit the feature to the container's width.\n\tprojection.fitSize([width, height], feature)\n\n\t// Get the individual line strings.\n\tconst lineStrings = _(feature.features)\n\t\t.map('geometry')\n\t\t.flatten()\n\t\t.map('coordinates')\n\t\t.flatten()\n\t\t.sortBy('length')\n\t\t.map(d => turf.lineString(d))\n\t\t.value()\n\n\t// Calculate the overall line string length.\n\tconst totalLength = _(lineStrings)\n\t\t.map(d => turf.lineDistance(d))\n\t\t.sum()\n\n\t// Desired number of total points.\n\tconst pointsCount = 1000\n\tlet pointsRemaining = pointsCount\n\n\tconst points = _(lineStrings)\n\t\t.map(line => {\n\n\t\t\t// How many points will this line get?\n\n\t\t\t// First, calculate this line's length.\n\t\t\tconst lineLength = turf.lineDistance(line)\n\n\t\t\t// Next, get this line's points proportion, rounded up.\n\t\t\tconst upperCount = Math.ceil(lineLength * pointsCount / totalLength)\n\n\t\t\t// Don't get more points that are available.\n\t\t\tconst linePointsCount = Math.min(pointsRemaining, upperCount)\n\n\t\t\t// Make sure to update points remaining.\n\t\t\tpointsRemaining -= linePointsCount\n\n\t\t\t// Now that we know how many points this line will get,\n\t\t\t// calculate the distance between points - the step:\n\t\t\tconst step = lineLength / linePointsCount\n\n\t\t\tconst linePoints = d3.range(linePointsCount)\n\t\t\t\t.map(d => turf.along(line, d * step))\n\n\t\t\treturn linePoints\n\n\t\t})\n\t\t.flatten()\n\t\t.map(d => projection(d.geometry.coordinates))\n\t\t.value()\n\n\t// This function adds the circles.\n\tconst enter = () => {\n\n\t\t// JOIN new data with old elements.\n\t\tconst circles = g.selectAll('circle')\n\t\t\t\t.data(points)\n\n\t\t// ENTER new elements present in new data.\n\t\tcircles.enter().append('circle')\n\t\t\t\t.attrs({\n\t\t\t\t\tcx: width/2,\n\t\t\t\t\tcy: height/2,\n\t\t\t\t\tr: 0,\n\t\t\t\t})\n\t\t\t.transition('enter')\n\t\t\t\t.duration(1000)\n\t\t\t\t.delay((d, i) => i * 10)\n\t\t\t\t.attrs({\n\t\t\t\t\tcx: d => d[0],\n\t\t\t\t\tcy: d => d[1],\n\t\t\t\t\tr: 1,\n\t\t\t\t})\n\n\t}\n\n\t// This function removes the circles.\n\tconst exit = () => {\n\n\t\t// JOIN new data with old elements.\n\t\tconst circles = g.selectAll('circle')\n\t\t\t\t.data(points)\n\n\t\t// UPDATE old elements present in new data.\n\t\tcircles\n\t\t\t.transition('exit')\n\t\t\t\t.duration(250)\n\t\t\t\t.delay((d, i) => i * 2)\n\t\t\t\t.attrs({\n\t\t\t\t\tcx: width/2,\n\t\t\t\t\tcy: height/2,\n\t\t\t\t\tr: 0,\n\t\t\t\t})\n\t\t\t.remove()\n\n\t}\n\n\t// Fire the enter function on page load.\n\tenter()\n\n\t// Listen to button clicks.\n\tdocument.querySelector('button.enter').addEventListener('click', enter)\n\tdocument.querySelector('button.exit').addEventListener('click', exit)\n\n})\n"]}
Raw
index.html
<!DOCTYPE html>
<title>Equidistant outline circles</title>
<link href='dist.css' rel='stylesheet' />
<body>
<div class='map'>
<svg></svg>
</div>
<div class='buttons'>
<button class='enter'>Enter</button>
<button class='exit'>Exit</button>
</div>
<script src='https://d3js.org/d3.v4.min.js'></script>
<script src='https://d3js.org/d3-selection-multi.v1.min.js'></script>
<script src='https://d3js.org/topojson.v2.min.js'></script>
<script src='https://npmcdn.com/@turf/turf@3.10.2/turf.min.js'></script>
<script src='https://cdn.jsdelivr.net/lodash/4.17.4/lodash.min.js'></script>
<script src='dist.js'></script>
</body>
Raw
Makefile
# Not used for Irish example. http://mapshaper.org/ used instead.
#all:
#
# rm boundary.topojson;
# mapshaper -i ~/Downloads/cb_2015_us_nation_5m/cb_2015_us_nation_5m.shp name=boundary -clip bbox=-126,23,-65,50 -filter-slivers min-area=700000000 -lines -simplify dp 5% -o format=topojson boundary.topojson;
Raw
script.js
// Setup chart dimensions.
const margin = { top: 10, right: 10, bottom: 10, left: 10 }
// Get GeoJSON.
d3.json('./boundary.topojson', json => {
const feature = topojson.feature(json, json.objects.boundary)
// Get feature's bounds and centroid.
const bounds = d3.geoBounds(feature)
const centroid = d3.geoCentroid(feature)
// const projection = d3.geoConicConformal()
// .parallels([bounds[0][1], bounds[1][1]])
// .rotate([-centroid[0], 0])
// .center([0, -centroid[1]])
const projection = d3.geoAlbers()
const rotate = [0,0,-45]
// Get the path.
const path = d3.geoPath().projection(projection).rotate(rotate)
// Get the path's bounds (i.e., in pixels).
const b = path.bounds(feature)
// Get aspect ratio.
const aspect = (b[1][0] - b[0][0]) / (b[1][1] - b[0][1])
const outerHeight = 460
const outerWidth = outerHeight * aspect
const width = outerWidth - margin.left - margin.right
const height = outerHeight - margin.top - margin.bottom
// Prepare svg.
const g = d3.select('.map svg')
.attrs({ width: outerWidth, height: outerHeight })
.append('g')
.attr('transform', `rotate(45) translate("+100+", "+-170+"))`)
// Fit the feature to the container's width.
projection.fitSize([width, height], feature)
// Get the individual line strings.
const lineStrings = _(feature.features)
.map('geometry')
.flatten()
.map('coordinates')
.flatten()
.sortBy('length')
.map(d => turf.lineString(d))
.value()
// Calculate the overall line string length.
const totalLength = _(lineStrings)
.map(d => turf.lineDistance(d))
.sum()
// Desired number of total points.
const pointsCount = 1000
let pointsRemaining = pointsCount
const points = _(lineStrings)
.map(line => {
// How many points will this line get?
// First, calculate this line's length.
const lineLength = turf.lineDistance(line)
// Next, get this line's points proportion, rounded up.
const upperCount = Math.ceil(lineLength * pointsCount / totalLength)
// Don't get more points that are available.
const linePointsCount = Math.min(pointsRemaining, upperCount)
// Make sure to update points remaining.
pointsRemaining -= linePointsCount
// Now that we know how many points this line will get,
// calculate the distance between points - the step:
const step = lineLength / linePointsCount
const linePoints = d3.range(linePointsCount)
.map(d => turf.along(line, d * step))
return linePoints
})
.flatten()
.map(d => projection(d.geometry.coordinates))
.value()
// This function adds the circles.
const enter = () => {
// JOIN new data with old elements.
const circles = g.selectAll('circle')
.data(points)
// ENTER new elements present in new data.
circles.enter().append('circle')
.attrs({
cx: width/2,
cy: height/2,
r: 0,
})
.transition('enter')
.duration(1000)
.delay((d, i) => i * 10)
.attrs({
cx: d => d[0],
cy: d => d[1],
r: 1,
})
}
// This function removes the circles.
const exit = () => {
// JOIN new data with old elements.
const circles = g.selectAll('circle')
.data(points)
// UPDATE old elements present in new data.
circles
.transition('exit')
.duration(250)
.delay((d, i) => i * 2)
.attrs({
cx: width/2,
cy: height/2,
r: 0,
})
.remove()
}
// Fire the enter function on page load.
enter()
// Listen to button clicks.
document.querySelector('button.enter').addEventListener('click', enter)
document.querySelector('button.exit').addEventListener('click', exit)
})
Raw
style.styl
$green = #008000
.buttons
margin 0 auto
text-align center
.map
svg
display block
margin 0 auto
circle
fill $green
fill-opacity 0.25
stroke $green
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