Multi-Series Line Chart-8/29-4

This line chart is constructed from a TSV file storing the daily average temperatures of New York, San Francisco and Austin over the last year. The chart employs conventional margins and a number of D3 features:

d3.tsv - load and parse data
d3.time.format - parse dates
d3.time.scale - x-position encoding
d3.scale.linear - y-position encoding
d3.scale.category10, a d3.scale.ordinal - color encoding
d3.extent, d3.min and d3.max - compute domains
d3.keys - compute column names
d3.svg.axis - display axes
d3.svg.line - display line shape

forked from mbostock's block: Multi-Series Line Chart

forked from ShuangjiaoHu's block: Multi-Series Line Chart-8/29-4

<!DOCTYPE html>
<meta charset="utf-8">
<style>

.axis--x path {
  display: none;
}

.line {
  fill: none;
  stroke: steelblue;
  stroke-width: 1.5px;
}

</style>
<svg width="960" height="500"></svg>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>

var svg = d3.select("svg"),
    margin = {top: 20, right: 80, bottom: 30, left: 50},
    width = svg.attr("width") - margin.left - margin.right,
    height = svg.attr("height") - margin.top - margin.bottom,
    g = svg.append("g").attr("transform", "translate(" + margin.left + "," + margin.top + ")");

var parseTime = d3.timeParse("%Y%m%d");

var clicked = -1;

var x = d3.scaleTime().range([0, width]),
    y = d3.scaleLinear().range([height, 0]),
    z = d3.scaleOrdinal(d3.schemeCategory10);

var line = d3.line()
    .curve(d3.curveBasis)
    .x(function(d) { return x(d.date); })
    .y(function(d) { return y(d.temperature); });

var zoom = d3.zoom();

d3.tsv("data.tsv", type, function(error, data) {

if (error) throw error;

x.domain(d3.extent(data, function(d) { return d.date; }));

y.domain([
    d3.min(cities, function(c) { return d3.min(c.values, function(d)
                                               { return d.temperature; }); }),
    d3.max(cities, function(c) { return d3.max(c.values, function(d)
                                               { return d.temperature; }); })
  ]);

z.domain(cities.map(function(c) { return c.id; }));

g.append("g")
      .attr("class", "axis axis--x")
      .attr("transform", "translate(0," + height + ")")
      .call(d3.axisBottom(x));

g.append("g")
      .attr("class", "axis axis--y")
      .call(d3.axisLeft(y))
    .append("text")
      .attr("transform", "rotate(-90)")
      .attr("y", 6)
      .attr("dy", "0.71em")
      .attr("fill", "#000")
      .text("Temperature, ºF");

var city = g.selectAll(".city")
    .data(cities)
    .enter().append("g")
      .attr("class", "city");

city.append("path")
      .attr("class", "line")
      .attr("d", function(d) { return line(d.values)})
  		.attr("id", function(d, i) { return 'tag'+i; })
      .style("stroke", function(d) { return z(d.id); });

city.append("text")
      .datum(function(d) { return {id: d.id, active: d.active, value:
                                   d.values[d.values.length - 1]}; })
      .attr("transform", function(d) { return "translate(" + x(d.value.date) + ","
                                   + y(d.value.temperature) + ")"; })
      .attr("x", 3)
      .attr("dy", "0.35em")
      .style("font", "10px sans-serif")
  		.on("click", function(d, i){
        var active = d.active==1 ? 0 : 1;
    		console.log(d.id);
        console.log("d.active:" + d.active);
    		console.log("active:" + active);
        newOpacity = active==0 ? 0 : 1;
    		clicked = active==0 ? i : -1;
    		if(clicked == i){
          d3.select("#arcSelection").remove();
        }
        d3.select("#tag"+i)
          .style("opacity", newOpacity);

d.active = active;
      })
  		.on("mouseover", function(d, i) {
    		if(clicked != i){
         g.append("path")
          .attr("class", "line")
          .attr("d", function() { return line(cities[i].values)})
          .attr("id", "arcSelection")
          .style("stroke", function() { return z(d.id); })
    			.style("stroke-width", 2);
        }

var j;
  			for(j = 0; j < 3; j++){
          if(i != j && i != clicked){
            console.log(j);
            d3.select("#tag"+j)
            .transition().duration(100)
            .style("stroke", "#d3d3d3");
          }
        }
  		})
  		.on("mouseout", function(d, i) {
    		d3.select("#arcSelection").remove();
    		var j;
  			for(j = 0; j < 3; j++){
          if(i != j){
            console.log(j);
            d3.select("#tag"+j)
            .transition().duration(100)
            .style("stroke", function(d) { return z(d.id); });
          }
        }
  		})
      .text(function(d) { return d.id; });

});

function type(d, _, columns) {
  d.date = parseTime(d.date);
  for (var i = 1, n = columns.length, c; i < n; ++i) d[c = columns[i]] = +d[c];
  return d;
}

</script>

https://d3js.org/d3.v4.min.js