Simple stream + interpolation, layout offset & axes by devgru

index.html

<!DOCTYPE html>
<meta charset='utf-8'>
<style>
    body { font: 10px sans-serif; }
    p { font: 12px helvetica; }

    .axis path, .axis line {
        fill: none;
        stroke: #000;
        stroke-width: 2px;
        shape-rendering: crispEdges;
    }
</style>
<body>
<script src='//d3js.org/d3.v4.js'></script>
<script src='//d3js.org/colorbrewer.v1.js'></script>
<script>
    var parse = d3.timeParse('%m/%d/%y')
    var margin = {top: 20, right: 40, bottom: 30, left: 30}
    var width = 600 - margin.left - margin.right
    var height = 400 - margin.top - margin.bottom
    var x = d3.scaleTime().range([0, width])
    var y = d3.scaleLinear().range([height - 10, 0])
    var color = d3.scaleOrdinal().range(colorbrewer['Blues'][6])

    var xAxis = d3.axisBottom()
            .scale(x)
    var yAxis = d3.axisLeft()
            .scale(y)
    var yAxis2 = d3.axisRight()
            .scale(y)

    var area = d3.area()
            .curve(d3.curveCardinalOpen)
            .x(function(d) { return x(d.date) })
            .y0(function(d) { return y(d.coords[0])  })
            .y1(function(d) { return y(d.coords[1]) })

    var svg = d3.select('body')
            .append('svg')
            .attr('width', width + margin.left + margin.right)
            .attr('height', height + margin.top + margin.bottom)
            .append('g')
            .attr('transform', 'translate(' + margin.left + ',' + margin.top + ')')

    function prepareData(data) {
        var nestedByDate = d3.nest()
        	.key(function(d) { return d.date })
					.entries(data);
      	var nestedByKey = d3.nest()
        	.key(function(d) { return d.key })
					.entries(data);
          
      	var keys = nestedByKey.map(function(d) { return d.key });

        var stack = d3.stack()
                .offset(d3.stackOffsetSilhouette) // wiggle
                .value(function(d, k) {
                  return d.values.filter(function(d) {
                    return d.key == k;
                  })[0].value
                })
        				.keys(keys)

        var result = stack(nestedByDate)
				nestedByKey.forEach(function(d, i) {
          d.values.forEach(function(v, j) {
            v.coords = result[i][j]
          })
        });
        return nestedByKey;
    }

    d3.csv('https://d3.devg.ru/data/stream.csv', function(d) {
        d.date = parse(d.date)
        d.value = Number(d.value)
        return d
    }, function (data) {
        var layers = prepareData(data)

        x.domain(d3.extent(data, function (d) { return d.date }))
        y.domain([
          d3.min(data, function (d) { return d.coords[0] }),
          d3.max(data, function (d) { return d.coords[1] })
        ])

        svg.selectAll('.layer')
                .data(layers)
                .enter().append('path')
                .attr('class', 'layer')
                .attr('d', function (d) {
          					return area(d.values) })
                .style('fill', function (d, i) { return color(i) })

        svg.append('g')
                .attr('class', 'x axis')
                .attr('transform', 'translate(0,' + height + ')')
                .call(xAxis)

        svg.append('g')
                .attr('class', 'y axis')
                .attr('transform', 'translate(' + width + ', 0)')
                .call(yAxis2)

        svg.append('g')
                .attr('class', 'y axis')
                .call(yAxis)
    })
</script>