D3 Block-a-Day: Day 3, January 3rd, 2017

D3 Block-a-Day: Day 3, January, 3rd 2017

New Year's Resolution for 2017: Make a D3 Block a day to teach myself D3. This is Number 3. This example modifies the line chart from January 2nd and attempts to create a scatter plot using some longitudinal education data. Props to Malcolm Maclean's D3.js Tips and Tricks V4 for detailed coding examples.

<!DOCTYPE html>
<meta charset="utf-8">
<head>
    <title>D3 Block-a-Day: Day 3, January 3, 2017</title>
    <link rel="stylesheet" type="text/css" href="styles.css"/>
    <script src="https://d3js.org/d3.v4.min.js"></script> 
    <style> /* set the CSS */

body {
				font: 20px Helvetica Neue;
		}

.dot {
				stroke: #000;
      	fill: #ffe0e0;
		}

.axis {
      	font: 14px Helvetica Neue;
     }

.grid line {
				stroke: lightgrey;
				stroke-opacity: 0.7;
				shape-rendering: crispEdges;
		}

.grid path {
				stroke-width: 0;
		}
    </style>
</head>

// set the dimensions and margins of the graph
var margin = {top: 20, right: 20, bottom: 50, left: 70},
    width = 960 - margin.left - margin.right,
    height = 500 - margin.top - margin.bottom;

// set the ranges
var x = d3.scaleLinear().range([0, width]);
var y = d3.scaleLinear().range([height, 0]);

// define the line
var valueline = d3.line()
    .x(function(d) { return x(d.date); })
    .y(function(d) { return y(d.close); });

// append the svg obgect to the body of the page
// appends a 'group' element to 'svg'
// moves the 'group' element to the top left margin
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 + ")");

// gridlines in x axis function
function make_x_gridlines() {
		return d3.axisBottom(x)
		.ticks(5)
}

// gridlines in y axis function
function make_y_gridlines() {
		return d3.axisLeft(y)
		.ticks(5)
}

// Get the data
d3.csv("scale_scores.csv", function(error, data) {
  if (error) throw error;

// format the data
  data.forEach(function(d) {
      d.scale_score_2015 = +d.SCALE_SCORE_2015;
      d.scale_score_2016 = +d.SCALE_SCORE_2016;
  });

// Scale the range of the data
  x.domain([200,800]);
  y.domain([200,800]);

svg.selectAll("dot")
			.data(data)
			.enter().append("circle")
 			.attr("class", "dot")
			.attr("r", 6)
			.attr("cx", function(d) { return x(d.scale_score_2015); })
			.attr("cy", function(d) { return y(d.scale_score_2016); });

// Add the x Axis
  svg.append("g")
      .attr("transform", "translate(0," + height + ")")
      .call(d3.axisBottom(x).ticks(5))
      .attr("class", "axis");

// text label for the x axis
  svg.append("text")
      .attr("transform",
            "translate(" + (width*0.1) + " ," +
                           (height + margin.top + 30) + ")")
      .style("text-anchor", "middle")
  		.style("font-family", "Helvetica Neue")
      .text("Scale Score 2015");

// Add the y Axis
  svg.append("g")
      .call(d3.axisLeft(y))
  		.style("font-family", "Helvetica Neue")
  		.attr("class", "axis");

// text label for the y axis
  svg.append("text")
      .attr("transform", "rotate(-90)")
      .attr("y", 0 - margin.left)
  		.attr("x", - 0.75*height)
      .attr("dy", "1em")
      .style("text-anchor", "middle")
  		.style("font-family", "Helvetica Neue")
      .text("Scale Score 2016");

// add the X gridlines
	svg.append("g")
			.attr("class", "grid")
			.attr("transform", "translate(0," + height + ")")
			.call(make_x_gridlines()
				.tickSize(-height)
				.tickFormat("")
			)
  
  // add the Y gridlines
	svg.append("g")
			.attr("class", "grid")
			.call(make_y_gridlines()
				.tickSize(-width)
				.tickFormat("")
			)
});

</script>
</body>

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