Multiline chart with filter

A simple example of a multiline chart, where lines can be selected or de-selected by clicking on the corresponding legend.

Adapted from an example by Bostock: /mbostock/3884955

forked from fabiomainardi's block: Multiline chart with filter

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

body {
  font: 10px sans-serif;
}

.axis path,
.axis line {
  fill: none;
  stroke: #000;
  shape-rendering: crispEdges;
}

.x.axis path {
  display: none;
}

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

</style>
<body>
<script src="https://d3js.org/d3.v3.js"></script>
<script>

var margin = {top: 20, right: 80, bottom: 30, left: 50},
    width = 960 - margin.left - margin.right,
    height = 500 - margin.top - margin.bottom;

var parseDate = d3.time.format("%Y%m%d").parse;

var x = d3.time.scale()
    .range([0, width]);

var y = d3.scale.linear()
    .range([height, 0]);

var color = d3.scale.category10();

var xAxis = d3.svg.axis()
    .scale(x)
    .orient("bottom");

var yAxis = d3.svg.axis()
    .scale(y)
    .orient("left");

var line = d3.svg.line()
    .interpolate("basis")
    .x(function(d) { return x(d.date); })
    .y(function(d) { return y(d.temperature); });

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 + ")");

// start chart 
  
var filterData={"Austin":false,"New York":true,"San Francisco":true};//cities to be shown

function drawChart(filterData){

d3.tsv("data.tsv", function(error, data) {
	color.domain(d3.keys(data[0]).filter(function(key) { return key !== "date"; }));

data.forEach(function(d) {
	d.date = parseDate(d.date);
});

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

svg.selectAll("*").remove();

//LEGEND
var legend = svg.selectAll('g')
	.data(cities)
	.enter()
	.append('g')
	.attr('class', 'legend');
    
legend.append('rect')
	.attr('x', width - 20)
	.attr('y', function(d, i){ return i *  20;})
	.attr('width', 10)
	.attr('height', 10)
	.style('fill', function(d) { 
	return color(d.name);
	});
      
legend.append('text')
	.attr('x', width - 8)
	.attr('y', function(d, i){ return (i *  20) + 9;})
	.text(function(d){ return d.name; });

legend
	.on("click",function(d){
	reDraw(d.name);
});
    	
svg.append("g")
	.attr("class", "x axis")
	.attr("transform", "translate(0," + height + ")")
	.call(xAxis);

svg.append("g")
	.attr("class", "y axis")
	.call(yAxis)
	.append("text")
	.attr("transform", "rotate(-90)")
	.attr("y", 6)
	.attr("dy", ".71em")
	.style("text-anchor", "end")
	.text("Temperature (ºF)");
   
var city = svg.selectAll(".city")
  .data(cities.filter(function(d){return filterData[d.name]==true;})) 
  .enter().append("g");
        
svg.selectAll(".city")
  .data(cities.filter(function(d){return filterData[d.name]==true;}))
  .append("g")
  .attr("class", "city");
      
svg.selectAll(".city")
	.data(cities.filter(function(d){return filterData[d.name]==true;}))
	.exit()
	.remove();
  
city.append("path")
	.attr("class", "line")
	.attr("d", function(d) { return line(d.values); })
	.style("stroke", function(d) { return color(d.name); });

city.append("text")
      .datum(function(d) { return {name: d.name, 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", ".35em")
      .text(function(d) { return d.name; });
    svg.selectAll(".city")
      .data(cities.filter(function(d){return filterData[d.name]==true;}))
      .exit()
      .remove();
});
} // end draw chart function

drawChart(filterData); // finally draw the chart

function reDraw(name){
	
	filterData[name]=!filterData[name];
	console.log(filterData);
  drawChart(filterData);
}

</script>

https://d3js.org/d3.v3.js