Line graph over time with multiple data points using SVG and d3.js

<html>
	<head>
		<title>Line graph over time with multiple data points using SVG and d3.js</title>
		<script src="https://cdn.jsdelivr.net/npm/d3@2.10.3/d3.v2.js"></script>
		<style>
			body {
				font-family: "Helvetica Neue", Helvetica;
			}
		
			/* tell the SVG path to be a thin blue line without any area fill */
			path {
				stroke-width: 1;
				fill: none;
			}
			
			.data1 {
				stroke: green;
			}

.data2 {
				stroke: orange;
			}
			
			.axis {
			  shape-rendering: crispEdges;
			}

.x.axis line {
			  stroke: lightgrey;
			}

.x.axis .minor {
			  stroke-opacity: .5;
			}

.x.axis path {
			  display: none;
			}
			
			.x.axis text {
				font-size: 10px;
			}

.y.axis line, .y.axis path {
			  fill: none;
			  stroke: #000;
			}
			
			.y.axis text {
				font-size: 12px;
			}

</style>
	</head>
	<body>

// create a line function that can convert data[] into x and y points
		var line1 = d3.svg.line()
			// assign the X function to plot our line as we wish
			.x(function(d,i) { 
				// verbose logging to show what's actually being done
				//console.log('Plotting X value for data point: ' + d + ' using index: ' + i + ' to be at: ' + x(i) + ' using our xScale.');
				// return the X coordinate where we want to plot this datapoint
				return x(startTime.getTime() + (timeStep*i)); 
			})
			.y(function(d) { 
				// verbose logging to show what's actually being done
				//console.log('Plotting Y value for data point: ' + d + ' to be at: ' + y(d) + " using our yScale.");
				// return the Y coordinate where we want to plot this datapoint
				return y(d[0]); // use the 1st index of data (for example, get 20 from [20,13])
			})
			
			var line2 = d3.svg.line()
				// assign the X function to plot our line as we wish
				.x(function(d,i) { 
					// verbose logging to show what's actually being done
					//console.log('Plotting X value for data point: ' + d + ' using index: ' + i + ' to be at: ' + x(i) + ' using our xScale.');
					// return the X coordinate where we want to plot this datapoint
					return x(startTime.getTime() + (timeStep*i)); 
				})
				.y(function(d) { 
					// verbose logging to show what's actually being done
					//console.log('Plotting Y value for data point: ' + d + ' to be at: ' + y(d) + " using our yScale.");
					// return the Y coordinate where we want to plot this datapoint
					return y(d[1]); // use the 2nd index of data (for example, get 13 from [20,13])
				})

// Add an SVG element with the desired dimensions and margin.
			var graph = d3.select("#graph").append("svg:svg")
			      .attr("width", w + m[1] + m[3])
			      .attr("height", h + m[0] + m[2])
			    .append("svg:g")
			      .attr("transform", "translate(" + m[3] + "," + m[0] + ")");

// create yAxis
			var xAxis = d3.svg.axis().scale(x).tickSize(-h).tickSubdivide(1);

// Add the x-axis.
			graph.append("svg:g")
			      .attr("class", "x axis")
			      .attr("transform", "translate(0," + h + ")")
			      .call(xAxis);

// create left yAxis
			var yAxisLeft = d3.svg.axis().scale(y).ticks(6).orient("left");
			// Add the y-axis to the left
			graph.append("svg:g")
			      .attr("class", "y axis")
			      .attr("transform", "translate(-10,0)")
			      .call(yAxisLeft);
			
  			// add lines
  			// do this AFTER the axes above so that the line is above the tick-lines
    		graph.append("svg:path").attr("d", line1(data)).attr("class", "data1");
    		graph.append("svg:path").attr("d", line2(data)).attr("class", "data2");

</script>

</body>
</html>

Modified http://mbostock.github.com/d3/d3.v2.js to a secure url

https://mbostock.github.com/d3/d3.v2.js