Time Series Histogram

Built with blockbuilder.org

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

body {
		  font: 10px sans-serif;
		}

.bar {
		  fill: steelblue;
		  shape-rendering: crispEdges;
		}

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

</style>
</html>
<body>
	<script src="https://d3js.org/d3.v3.min.js"></script>
	<script>
		var margin = {top: 10, right: 30, bottom: 30, left: 50},
		    width = 960 - margin.left - margin.right,
		    height = 500 - margin.top - margin.bottom;

var parseDate = d3.time.format("%m/%d/%Y %I:%M:%S %p").parse;
		var formatDate = d3.time.format("%m/%y");
		var formatCount = d3.format(",.0f");

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

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

var yAxis = d3.svg.axis().scale(y)
		  .orient("left").ticks(6);

// Create the SVG drawing area
		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 + ")");

// Get the data
		d3.csv("Rat_Sightings.csv", function(error, data) {

// Parse the date strings into javascript dates
		  data.forEach(function(d) {
		    d.created_date = parseDate(d["Created Date"]);
		  });

// Determine the first and list dates in the data set
		  var monthExtent = d3.extent(data, function(d) { return d.created_date; });

// Create one bin per month, use an offset to include the first and last months
		  var monthBins = d3.time.months(d3.time.month.offset(monthExtent[0],-1),
		                                 d3.time.month.offset(monthExtent[1],1));

// Use the histogram layout to create a function that will bin the data
		  var binByMonth = d3.layout.histogram()
		    .value(function(d) { return d.created_date; })
		    .bins(monthBins);

// Bin the data by month
		  var histData = binByMonth(data);

// Scale the range of the data by setting the domain
		  x.domain(d3.extent(monthBins));
		  y.domain([0, d3.max(histData, function(d) { return d.y; })]);

// Set up one bar for each bin
		  // Months have slightly different lengths so calculate the width for each bin
		  // Note: dx, the width of the histogram bin, is in milliseconds so convert the x value
		  // into UTC time and convert the sum back to a date in order to help calculate the width
		  // Thanks to npdoty for pointing this out in this stack overflow post:
		  // https://stackoverflow.com/questions/17745682/d3-histogram-date-based
		  svg.selectAll(".bar")
		      .data(histData)
		    .enter().append("rect")
		      .attr("class", "bar")
		      .attr("x", function(d) { return x(d.x); })
		      .attr("width", function(d) { return x(new Date(d.x.getTime() + d.dx))-x(d.x)-1; })
		      .attr("y", function(d) { return y(d.y); })
		      .attr("height", function(d) { return height - y(d.y); });

// Add the X Axis
		  svg.append("g")
		      .attr("class", "x axis")
		      .attr("transform", "translate(0," + height + ")")
		      .call(xAxis);

// Add the Y Axis and label
		  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("Number of Sightings");

});

</script>
</body>

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