Balance of power

.block

license: mit
height: 720
border: no

README.md

Balance of power

dist.css

.container{margin:1em;padding:0;position:relative}.container img{width:100%;opacity:1}span.label{display:inline-block;text-align:center;font-weight:700;width:2.75em}span.label.total{width:20em;text-align:left}input{width:100%}svg{display:block;border:1px solid red;width:50%;margin:0 auto}svg circle.ring{fill:none;stroke:grey;stroke-width:.01px}svg circle.dem{fill:#00f}svg circle.gop{fill:red}svg circle.ind{fill:green}svg circle.none{fill:grey;opacity:.25}

dist.js

var rows=[d3.range(23),d3.range(26),d3.range(30),d3.range(32),d3.range(36),d3.range(38),d3.range(42),d3.range(46),d3.range(50),d3.range(54),d3.range(58)],totalSeats=d3.merge(rows).length,RADIUS=2.25,outerWidth=200,outerHeight=outerWidth/2+RADIUS,width=outerWidth-2*RADIUS,height=outerHeight-RADIUS,gap=width/2*.4,svg=d3.select("svg").attr("viewBox","0 0 "+outerWidth+" "+outerHeight).append("g").attr("transform","translate("+outerWidth/2+", "+height+")"),updateElement=function(t,e){return document.querySelector(t).textContent=e},drawData=function(){var t=+document.querySelector("input.dem").value,e=+document.querySelector("input.ind").value,n=+document.querySelector("input.gop").value;updateElement("span.dem",t),updateElement("span.ind",e),updateElement("span.gop",n);var a=totalSeats-(t+e+n);if(a>=0){updateElement("span.total",t+e+n+" out of "+totalSeats);var r=t,o=e,i=n,l=rows.map(function(a){return{total:a.length,demPortion:Math.ceil(t*a.length/totalSeats),indPortion:Math.ceil(e*a.length/totalSeats),gopPortion:Math.ceil(n*a.length/totalSeats)}}),d=l.map(function(t,e,n){var a,l,d,u,s=t.total,c=t.demPortion,g=t.indPortion,p=t.gopPortion;if(e===n.length-1)a=r,l=o,d=i,u=s-(a+l+d);else{u=s;var m=r>0?Math.min(r,c):0,h=u>0?Math.min(u,m):0;a=h,u-=a,r-=a;var S=o>0?Math.min(o,g):0,v=u>0?Math.min(u,S):0;l=v,u-=l,o-=l;var f=i>0?Math.min(i,p):0,w=u>0?Math.min(u,f):0;d=w,u-=d,i-=d}return{demSeats:a,indSeats:l,noneSeats:u,gopSeats:d,total:s}}),u=d3.merge(d.map(function(t,e){return d3.merge([d3.range(t.demSeats).map(function(){return"dem"}),d3.range(t.indSeats).map(function(){return"ind"}),d3.range(t.noneSeats).map(function(){return"none"}),d3.range(t.gopSeats).map(function(){return"gop"})]).reverse().map(function(t,n,a){return{party:t,row:e,seat:n,rowSeats:a.length}})})),s=d.length,c=d3.scalePoint().range([gap,width/2]).domain(d3.range(s+1));svg.selectAll("*").remove();var g=(svg.selectAll("circle.ring").data(d).enter().append("circle").attr("class","ring").attr("r",function(t,e){return c(e+1)}).attr("cx",0).attr("cy",0),svg.selectAll("circle.seat").data(u).enter().append("circle").attr("class",function(t){return t.party+" seat"}).attr("r",RADIUS).attr("cx",function(t){return c(t.row+1)}).attr("cy",0).attr("transform",function(t,e){return"rotate(-"+180/(t.rowSeats-1)*t.seat+")"}),svg.selectAll("circle.seat.dem").size()),p=svg.selectAll("circle.seat.ind").size(),m=svg.selectAll("circle.seat.gop").size();g===t&&p===e&&m===n||(alert("error! see the console. slider input did not match graph dots."),console.error(JSON.stringify({dem:{input:t,output:g},ind:{input:e,output:p},gop:{input:n,output:m}},null,2)))}else updateElement("span.total","Total exceeds available seats!")};d3.selectAll("input").on("input",function(t){return drawData()}),drawData();
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RADIUS * 2\nconst height = outerHeight - RADIUS\n\nconst gap = (width / 2) * 0.4\n\nconst svg = d3.select('svg')\n\t\t.attr('viewBox', `0 0 ${outerWidth} ${outerHeight}`)\n\t.append('g')\n\t\t.attr('transform',\n\t\t\t`translate(${outerWidth/2}, ${height})`)\n\nconst updateElement = (selector, value) =>\n\tdocument.querySelector(selector).textContent = value\n\nconst drawData = () => {\n\n\tconst dem = +document.querySelector('input.dem').value\n\tconst ind = +document.querySelector('input.ind').value\n\tconst gop = +document.querySelector('input.gop').value\n\tupdateElement('span.dem', dem)\n\tupdateElement('span.ind', ind)\n\tupdateElement('span.gop', gop)\n\t\n\t// This is each party's seats.\n\tconst none = totalSeats - (dem + ind + gop)\n\n\tif (none >= 0) {\n\n\t\tupdateElement('span.total', `${(dem + ind + gop)} out of ${totalSeats}`)\n\n\t\t// We'll use these variables to track remaining seats.\n\t\tlet demSeatsLeft = dem\n\t\tlet indSeatsLeft = ind\n\t\tlet gopSeatsLeft = gop\n\n\t\t// STEP 1:\n\t\t// Calculate each row's ratio of party seats, rounded up.\n\t\tconst rowProportions = rows.map(row => ({\n\t\t\t\ttotal: row.length,\n\t\t\t\tdemPortion: Math.ceil(dem * row.length / totalSeats),\n\t\t\t\tindPortion: Math.ceil(ind * row.length / totalSeats),\n\t\t\t\tgopPortion: Math.ceil(gop * row.length / totalSeats),\n\t\t\t}))\n\n\t\t// STEP 2:\n\t\t// Assign seats until we run out of total party seats.\n\t\t// For each row,\n\t\tconst seatRows = rowProportions.map((row, index, array) => {\n\n\t\t\tconst { total, demPortion, indPortion, gopPortion } = row\n\t\t\tlet demSeats\n\t\t\tlet indSeats\n\t\t\tlet gopSeats\n\t\t\tlet rowSeatsLeft\n\n\t\t\t// If this is the last row, simply assign all leftover seats.\n\t\t\tif (index === array.length - 1) {\n\n\t\t\t\tdemSeats = demSeatsLeft\n\t\t\t\tindSeats = indSeatsLeft\n\t\t\t\tgopSeats = gopSeatsLeft\n\t\t\t\trowSeatsLeft = total - (demSeats + indSeats + gopSeats)\n\n\t\t\t} else {\n\n\t\t\t\t// If this is NOT the last row, let's proceed.\n\n\t\t\t\trowSeatsLeft = total\n\n\t\t\t\t// We want to assign dem seats to this row. Remember that we\n\t\t\t\t// have `demSeatsLeft`, all the seats we have left.\n\t\t\t\t// We want to assign as many of those as possible, given our remaining\n\t\t\t\t// slots.\n\t\t\t\t// So first, IF there are dem seats left, find the min of demSeatsLeft\n\t\t\t\t// and demProportion:\n\t\t\t\tconst demSeatsToAssign = demSeatsLeft > 0 ?\n\t\t\t\t\tMath.min(demSeatsLeft, demPortion) : 0\n\n\t\t\t\t// Next, find the available slots left on this row, and seat as many as\n\t\t\t\t// possible, which is the min of rowSeatsLeft and demSeatsToAssign.\n\t\t\t\tconst demSeatsAvailable = rowSeatsLeft > 0 ?\n\t\t\t\t\tMath.min(rowSeatsLeft, demSeatsToAssign) : 0\n\n\t\t\t\t// This will be the actual dem seats we assign to this row.\n\t\t\t\tdemSeats = demSeatsAvailable\n\n\t\t\t\t// Finally, update this row's seats left,\n\t\t\t\trowSeatsLeft -= demSeats\n\n\t\t\t\t// and update demSeatsLeft.\n\t\t\t\tdemSeatsLeft -= demSeats\n\n\t\t\t\t// We'll do the same thing for ind:\n\t\t\t\tconst indSeatsToAssign = indSeatsLeft > 0 ?\n\t\t\t\t\tMath.min(indSeatsLeft, indPortion) : 0\n\t\t\t\tconst indSeatsAvailable = rowSeatsLeft > 0 ?\n\t\t\t\t\tMath.min(rowSeatsLeft, indSeatsToAssign) : 0\n\t\t\t\tindSeats = indSeatsAvailable\n\t\t\t\trowSeatsLeft -= indSeats\n\t\t\t\tindSeatsLeft -= indSeats\n\n\t\t\t\t// and gop.\n\t\t\t\tconst gopSeatsToAssign = gopSeatsLeft > 0 ?\n\t\t\t\t\tMath.min(gopSeatsLeft, gopPortion) : 0\n\t\t\t\tconst gopSeatsAvailable = rowSeatsLeft > 0 ?\n\t\t\t\t\tMath.min(rowSeatsLeft, gopSeatsToAssign) : 0\n\t\t\t\tgopSeats = gopSeatsAvailable\n\t\t\t\trowSeatsLeft -= gopSeats\n\t\t\t\tgopSeatsLeft -= gopSeats\n\n\t\t\t}\n\n\t\t\treturn {\n\t\t\t\tdemSeats,\n\t\t\t\tindSeats,\n\t\t\t\tnoneSeats: rowSeatsLeft,\n\t\t\t\tgopSeats,\n\t\t\t\ttotal,\n\t\t\t}\n\n\t\t})\n\n\t\t// Convert `seatRows` to the structure we need: an array of seats.\n\t\tconst seats = d3.merge(\n\t\t\tseatRows.map((row, i) =>\n\t\t\t\td3.merge([\n\t\t\t\t\td3.range(row.demSeats).map(() => 'dem'),\n\t\t\t\t\td3.range(row.indSeats).map(() => 'ind'),\n\t\t\t\t\td3.range(row.noneSeats).map(() => 'none'),\n\t\t\t\t\td3.range(row.gopSeats).map(() => 'gop'),\n\t\t\t\t])\n\t\t\t\t.reverse()\n\t\t\t\t.map((party, seat, a) => ({ party, row: i, seat, rowSeats: a.length }))\n\t\t\t)\n\t\t)\n\n\t\tconst ROWS = seatRows.length\n\n\t\tconst ringWidth = d3.scalePoint()\n\t\t\t.range([gap, width/2])\n\t\t\t.domain(d3.range(ROWS + 1))\n\n\t\tsvg.selectAll('*').remove()\n\t\t\n\t\tconst rings = svg.selectAll('circle.ring')\n\t\t\t\t.data(seatRows)\n\t\t\t.enter().append('circle')\n\t\t\t\t.attr('class', 'ring')\n\t\t\t\t.attr('r', (d, i) => ringWidth(i + 1))\n\t\t\t\t.attr('cx', 0)\n\t\t\t\t.attr('cy', 0)\n\n\t\tconst circleSeats = svg.selectAll('circle.seat')\n\t\t\t\t.data(seats)\n\t\t\t.enter().append('circle')\n\t\t\t\t.attr('class', d => `${d.party} seat`)\n\t\t\t\t.attr('r', RADIUS)\n\t\t\t\t.attr('cx', d => ringWidth(d.row + 1))\n\t\t\t\t.attr('cy', 0)\n\t\t\t\t.attr('transform', (d, i) => `rotate(-${180/(d.rowSeats - 1) * d.seat})`)\n\n\t\tconst demSelectionSize = svg.selectAll('circle.seat.dem').size()\n\t\tconst indSelectionSize = svg.selectAll('circle.seat.ind').size()\n\t\tconst gopSelectionSize = svg.selectAll('circle.seat.gop').size()\n\n\t\tif (!(demSelectionSize === dem &&\n\t\t\tindSelectionSize === ind &&\n\t\t\tgopSelectionSize === gop)) {\n\n\t\t\talert('error! see the console. slider input did not match graph dots.')\n\n\t\t\tconsole.error(JSON.stringify({\n\t\t\t\tdem: { input: dem, output: demSelectionSize },\n\t\t\t\tind: { input: ind, output: indSelectionSize },\n\t\t\t\tgop: { input: gop, output: gopSelectionSize },\n\t\t\t}, null, 2))\n\n\t\t}\n\n\t} else {\n\n\t\tupdateElement('span.total', `Total exceeds available seats!`)\n\n\t}\n\n}\n\nd3.selectAll('input').on('input', d => drawData())\ndrawData()\n"]}

index.html

<!DOCTYPE html>
<title>Dot matrix</title>
<link href='dist.css' rel='stylesheet' />
<body>
	<p>US House balance of power</p>

	<div class='container'>
	
		<div class="intro">

			<p>Dem <span class="dem label">100</span><input class="dem" type="range" min="0" max="435" value="100"></span></p>

			<p>Ind <span class="ind label">100</span><input class="ind" type="range" min="0" max="435" value="100"></span></p>

			<p>GOP <span class="gop label">100</span><input class="gop" type="range" min="0" max="435" value="100"></span></p>

			<p>Total: <span class="total label"></span></p>

		</div>
	
		<svg></svg>
	</div>
	
 	<script src='https://cdn.jsdelivr.net/lodash/4.16.6/lodash.min.js'></script>
	<script src='https://d3js.org/d3.v4.min.js'></script>
	<script src='dist.js'></script>

</body>

preview.png

script.js

// This array of arrays represents our desired seating arrangement.
// Each new row has more seats than the previous one.
const rows = [
	d3.range(23),
	d3.range(26),
	d3.range(30),
	d3.range(32),
	d3.range(36),
	d3.range(38),
	d3.range(42),
	d3.range(46),
	d3.range(50),
	d3.range(54),
	d3.range(58),
]

// The total number of seats.
const totalSeats = d3.merge(rows).length

const RADIUS = 2.25

const outerWidth = 200
const outerHeight = (outerWidth / 2) + RADIUS

const width = outerWidth - RADIUS * 2
const height = outerHeight - RADIUS

const gap = (width / 2) * 0.4

const svg = d3.select('svg')
		.attr('viewBox', `0 0 ${outerWidth} ${outerHeight}`)
	.append('g')
		.attr('transform',
			`translate(${outerWidth/2}, ${height})`)

const updateElement = (selector, value) =>
	document.querySelector(selector).textContent = value

const drawData = () => {

	const dem = +document.querySelector('input.dem').value
	const ind = +document.querySelector('input.ind').value
	const gop = +document.querySelector('input.gop').value
	updateElement('span.dem', dem)
	updateElement('span.ind', ind)
	updateElement('span.gop', gop)
	
	// This is each party's seats.
	const none = totalSeats - (dem + ind + gop)

	if (none >= 0) {

		updateElement('span.total', `${(dem + ind + gop)} out of ${totalSeats}`)

		// We'll use these variables to track remaining seats.
		let demSeatsLeft = dem
		let indSeatsLeft = ind
		let gopSeatsLeft = gop

		// STEP 1:
		// Calculate each row's ratio of party seats, rounded up.
		const rowProportions = rows.map(row => ({
				total: row.length,
				demPortion: Math.ceil(dem * row.length / totalSeats),
				indPortion: Math.ceil(ind * row.length / totalSeats),
				gopPortion: Math.ceil(gop * row.length / totalSeats),
			}))

		// STEP 2:
		// Assign seats until we run out of total party seats.
		// For each row,
		const seatRows = rowProportions.map((row, index, array) => {

			const { total, demPortion, indPortion, gopPortion } = row
			let demSeats
			let indSeats
			let gopSeats
			let rowSeatsLeft

			// If this is the last row, simply assign all leftover seats.
			if (index === array.length - 1) {

				demSeats = demSeatsLeft
				indSeats = indSeatsLeft
				gopSeats = gopSeatsLeft
				rowSeatsLeft = total - (demSeats + indSeats + gopSeats)

			} else {

				// If this is NOT the last row, let's proceed.

				rowSeatsLeft = total

				// We want to assign dem seats to this row. Remember that we
				// have `demSeatsLeft`, all the seats we have left.
				// We want to assign as many of those as possible, given our remaining
				// slots.
				// So first, IF there are dem seats left, find the min of demSeatsLeft
				// and demProportion:
				const demSeatsToAssign = demSeatsLeft > 0 ?
					Math.min(demSeatsLeft, demPortion) : 0

				// Next, find the available slots left on this row, and seat as many as
				// possible, which is the min of rowSeatsLeft and demSeatsToAssign.
				const demSeatsAvailable = rowSeatsLeft > 0 ?
					Math.min(rowSeatsLeft, demSeatsToAssign) : 0

				// This will be the actual dem seats we assign to this row.
				demSeats = demSeatsAvailable

				// Finally, update this row's seats left,
				rowSeatsLeft -= demSeats

				// and update demSeatsLeft.
				demSeatsLeft -= demSeats

				// We'll do the same thing for ind:
				const indSeatsToAssign = indSeatsLeft > 0 ?
					Math.min(indSeatsLeft, indPortion) : 0
				const indSeatsAvailable = rowSeatsLeft > 0 ?
					Math.min(rowSeatsLeft, indSeatsToAssign) : 0
				indSeats = indSeatsAvailable
				rowSeatsLeft -= indSeats
				indSeatsLeft -= indSeats

				// and gop.
				const gopSeatsToAssign = gopSeatsLeft > 0 ?
					Math.min(gopSeatsLeft, gopPortion) : 0
				const gopSeatsAvailable = rowSeatsLeft > 0 ?
					Math.min(rowSeatsLeft, gopSeatsToAssign) : 0
				gopSeats = gopSeatsAvailable
				rowSeatsLeft -= gopSeats
				gopSeatsLeft -= gopSeats

			}

			return {
				demSeats,
				indSeats,
				noneSeats: rowSeatsLeft,
				gopSeats,
				total,
			}

		})

		// Convert `seatRows` to the structure we need: an array of seats.
		const seats = d3.merge(
			seatRows.map((row, i) =>
				d3.merge([
					d3.range(row.demSeats).map(() => 'dem'),
					d3.range(row.indSeats).map(() => 'ind'),
					d3.range(row.noneSeats).map(() => 'none'),
					d3.range(row.gopSeats).map(() => 'gop'),
				])
				.reverse()
				.map((party, seat, a) => ({ party, row: i, seat, rowSeats: a.length }))
			)
		)

		const ROWS = seatRows.length

		const ringWidth = d3.scalePoint()
			.range([gap, width/2])
			.domain(d3.range(ROWS + 1))

		svg.selectAll('*').remove()
		
		const rings = svg.selectAll('circle.ring')
				.data(seatRows)
			.enter().append('circle')
				.attr('class', 'ring')
				.attr('r', (d, i) => ringWidth(i + 1))
				.attr('cx', 0)
				.attr('cy', 0)

		const circleSeats = svg.selectAll('circle.seat')
				.data(seats)
			.enter().append('circle')
				.attr('class', d => `${d.party} seat`)
				.attr('r', RADIUS)
				.attr('cx', d => ringWidth(d.row + 1))
				.attr('cy', 0)
				.attr('transform', (d, i) => `rotate(-${180/(d.rowSeats - 1) * d.seat})`)

		const demSelectionSize = svg.selectAll('circle.seat.dem').size()
		const indSelectionSize = svg.selectAll('circle.seat.ind').size()
		const gopSelectionSize = svg.selectAll('circle.seat.gop').size()

		if (!(demSelectionSize === dem &&
			indSelectionSize === ind &&
			gopSelectionSize === gop)) {

			alert('error! see the console. slider input did not match graph dots.')

			console.error(JSON.stringify({
				dem: { input: dem, output: demSelectionSize },
				ind: { input: ind, output: indSelectionSize },
				gop: { input: gop, output: gopSelectionSize },
			}, null, 2))

		}

	} else {

		updateElement('span.total', `Total exceeds available seats!`)

	}

}

d3.selectAll('input').on('input', d => drawData())
drawData()

style.styl

.container
	margin 1em
	padding 0
	position relative
	
	img
		width 100%
		opacity 1

span.label
	display inline-block
	text-align center
	font-weight bold
	width 2.75em
	&.total
		width 20em
		text-align left
		
input
	width 100%

svg
	display block
	border solid red 1px
	width 50%
	margin 0 auto
	
	circle

		&.ring
			fill none
			stroke grey
			stroke-width 0.01px

		&.dem
			fill blue

		&.gop
			fill red

		&.ind
			fill green

		&.none
			fill grey
			opacity 0.25

thumbnail.png