D3 4.0 Sequential Scales Explorer

An upgrade of mbostock's block: Heatmap (2D Histogram, CSV) to D3 4.0, with the addition of a select menu for D3 Sequential Scale Interpolators. Inspired by d3-scale issue: sequential.interpolate? #67. Draws the idea of trying out color schemes from colorbrewer2.org.

Also includes scales from d3-scale-chromatic.

forked from curran's block: Heatmap (2D Histogram, CSV) 4.0

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

body {
    font: 10px sans-serif;
  }

.label {
    font-weight: bold;
  }

.tile {
    shape-rendering: crispEdges;
  }

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

#interpolators {
    position: fixed;
    top: 1px;
    right: 1px;
  }

</style>
</head>
<body>
  
  <svg id="chart"></svg>
  <select id="interpolators"></select>

var margin = {top: 20, right: 90, bottom: 30, left: 50},
    width = 960 - margin.left - margin.right,
    height = 500 - margin.top - margin.bottom;

var parseDate = d3.timeParse("%Y-%m-%d"),
    formatDate = d3.timeFormat("%b %d");

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

// The size of the buckets in the CSV data file.
// This could be inferred from the data if it weren't sparse.
var xStep = 864e5,
    yStep = 100;

var svg = d3.select("#chart")
    .attr("width", width + margin.left + margin.right)
    .attr("height", height + margin.top + margin.bottom)
  .append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

d3.csv("data.csv", function(error, buckets) {
  if (error) throw error;

// Coerce the CSV data to the appropriate types.
  buckets.forEach(function(d) {
    d.date = parseDate(d.date);
    d.bucket = +d.bucket;
    d.count = +d.count;
  });

// Compute the scale domains.
  x.domain(d3.extent(buckets, function(d) { return d.date; }));
  y.domain(d3.extent(buckets, function(d) { return d.bucket; }));
  z.domain([0, d3.max(buckets, function(d) { return d.count; })]);

// Extend the x- and y-domain to fit the last bucket.
  // For example, the y-bucket 3200 corresponds to values [3200, 3300].
  x.domain([x.domain()[0], +x.domain()[1] + xStep]);
  y.domain([y.domain()[0], y.domain()[1] + yStep]);

// Display the tiles for each non-zero bucket.
  // See https://bl.ocks.org/3074470 for an alternative implementation.
  svg.selectAll(".tile")
      .data(buckets)
    .enter().append("rect")
      .attr("class", "tile")
      .attr("x", function(d) { return x(d.date); })
      .attr("y", function(d) { return y(d.bucket + yStep); })
      .attr("width", x(xStep) - x(0))
      .attr("height",  y(0) - y(yStep))
      .style("fill", function(d) { return z(d.count); });

// Add a legend for the color values.
  var legend = svg.selectAll(".legend")
      .data(z.ticks(6).slice(1).reverse())
    .enter().append("g")
      .attr("class", "legend")
      .attr("transform", function(d, i) { return "translate(" + (width + 20) + "," + (20 + i * 20) + ")"; });

legend.append("rect")
      .attr("width", 20)
      .attr("height", 20)
      .style("fill", z);

legend.append("text")
      .attr("x", 26)
      .attr("y", 10)
      .attr("dy", ".35em")
      .text(String);

svg.append("text")
      .attr("class", "label")
      .attr("x", width + 20)
      .attr("y", 10)
      .attr("dy", ".35em")
      .text("Count");

// Add an x-axis with label.
  svg.append("g")
      .attr("class", "x axis")
      .attr("transform", "translate(0," + height + ")")
      .call(d3.axisBottom().scale(x).ticks(d3.timeDay).tickFormat(formatDate))
    .append("text")
      .attr("class", "label")
      .attr("x", width)
      .attr("y", -6)
      .attr("text-anchor", "end")
      .text("Date");

// Add a y-axis with label.
  svg.append("g")
      .attr("class", "y axis")
      .call(d3.axisLeft().scale(y))
    .append("text")
      .attr("class", "label")
      .attr("y", 6)
      .attr("dy", ".71em")
      .attr("text-anchor", "end")
      .attr("transform", "rotate(-90)")
      .text("Value");
  
  var interpolators = [
    
    // These are from d3-scale.
    "Viridis",
    "Inferno",
    "Magma",
    "Plasma",
    "Warm",
    "Cool",
    "Rainbow",
    "CubehelixDefault",
    
    // These are from d3-scale-chromatic
    "Blues",
    "Greens",
    "Greys",
    "Oranges",
    "Purples",
    "Reds",
    "BuGn",
    "BuPu",
    "GnBu",
    "OrRd",
    "PuBuGn",
    "PuBu",
    "PuRd",
    "RdPu",
    "YlGnBu",
    "YlGn",
    "YlOrBr",
    "YlOrRd"
  ];
  
  var autoCycle = setInterval(function (){
    var node = d3.select("#interpolators").node();
    var i = node.selectedIndex;
    i = (i + 1) % interpolators.length;
    setSelectedInterpolator(interpolators[i]);
    node.selectedIndex = i;
  }, 1000);

d3.select("#interpolators")
    .on("change", function (){
      setSelectedInterpolator(interpolators[this.selectedIndex]);
      clearInterval(autoCycle);
    }) 
    .selectAll("option").data(interpolators)
    .enter().append("option")
      .attr("value", function (d){ return d; })
      .text(function (d){ return d; });

function setSelectedInterpolator(name, transitionDuration){

if(typeof transitionDuration === "undefined"){
      transitionDuration = 500;
    }
    
    z.interpolator(d3["interpolate" + name]);

svg.selectAll(".tile")
      .transition().duration(transitionDuration)
      .style("fill", function(d) { return z(d.count); });
    
    svg.selectAll(".legend rect")
      .transition().duration(transitionDuration)
      .style("fill", z);
    
    window.location.hash = name;
    d3.select("#interpolators").node().selectedIndex = interpolators.indexOf(name);
  }
  
  if(window.location.hash){
    clearInterval(autoCycle);
    setSelectedInterpolator(window.location.hash.replace("#", ""), 0);
  }
  
});
 
  
</script>
</body>
</html

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

https://d3js.org/d3-scale-chromatic.v0.3.min.js