Scatterplot Pills

Example of a scatter plot with brush using d3.js v4.

Tutorial at http://www.rajvansia.com/scatterplotbrush-d3-v4.html

Adapted from https://bl.ocks.org/mbostock/34f08d5e11952a80609169b7917d4172

forked from rajvansia's block: Scatterplot with brush d3 v4

<!DOCTYPE html>

<meta charset="utf-8">

var margin = {top: 20, right: 20, bottom: 110, left: 50},
    margin2 = {top: 430, right: 20, bottom: 30, left: 40},
    width = 960 - margin.left - margin.right,
    height = 500 - margin.top - margin.bottom,
    height2 = 500 - margin2.top - margin2.bottom;
  
var pillWidth = 5;
var pillHeight = 10;

var parseDate = d3.timeParse("%b %Y");

var x = d3.scaleTime().range([0, width]),
    x2 = d3.scaleTime().range([0, width]),
    y = d3.scaleLinear().range([height, 0]),
    y2 = d3.scaleLinear().range([height2, 0]);

var xAxis = d3.axisBottom(x),
    xAxis2 = d3.axisBottom(x2),
    yAxis = d3.axisLeft(y);

var brush = d3.brushX()
    .extent([[0, 0], [width, height2]])
    .on("brush", brushed);

var svg = d3.select("body").append("svg")
    .attr("width", width + margin.left + margin.right)
    .attr("height", height + margin.top + margin.bottom);

svg.append("defs").append("clipPath")
    .attr("id", "clip")
  .append("rect")
    .attr("width", width)
    .attr("height", height);

var focus = svg.append("g")
    .attr("class", "focus")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

var context = svg.append("g")
    .attr("class", "context")
    .attr("transform", "translate(" + margin2.left + "," + margin2.top + ")");

d3.csv("sp500.csv", type, function(error, data) {
  if (error) throw error;

x.domain(d3.extent(data, function(d) { return d.date; }));
  y.domain([0, d3.max(data, function(d) { return d.price; })+200]);
  x2.domain(x.domain());
  y2.domain(y.domain());

// append scatter plot to main chart area 
 var dots = focus.append("g");
    dots.attr("clip-path", "url(#clip)");
    dots.selectAll("dot")
        .data(data)
        .enter().append("rect")
        .attr('class', 'dot')
        .attr("width",pillWidth)
        .attr("height",pillHeight)
        .attr("rx", pillWidth / 2)
        .style("opacity", .5)
        .attr("x", function(d) { return x(d.date) - pillWidth / 2; })
        .attr("y", function(d) { return y(d.price) - pillHeight / 2; })
        
focus.append("g")
      .attr("class", "axis axis--x")
      .attr("transform", "translate(0," + height + ")")
      .call(xAxis);

focus.append("g")
      .attr("class", "axis axis--y")
      .call(yAxis);
      
focus.append("text")
      .attr("transform", "rotate(-90)")
      .attr("y", 0 - margin.left)
      .attr("x",0 - (height / 2))
      .attr("dy", "1em")
      .style("text-anchor", "middle")
      .text("Price");  
      
svg.append("text")             
      .attr("transform",
            "translate(" + ((width + margin.right + margin.left)/2) + " ," + 
                           (height + margin.top + margin.bottom) + ")")
      .style("text-anchor", "middle")
      .text("Date");
      
// append scatter plot to brush chart area      
 var dots = context.append("g");
     dots.attr("clip-path", "url(#clip)");
     dots.selectAll("dot")
        .data(data)
        .enter().append("circle")
        .attr('class', 'dotContext')
        .attr("r",3)
        .style("opacity", .5)
        .attr("cx", function(d) { return x2(d.date); })
        .attr("cy", function(d) { return y2(d.price); })
        
context.append("g")
      .attr("class", "axis axis--x")
      .attr("transform", "translate(0," + height2 + ")")
      .call(xAxis2);

context.append("g")
      .attr("class", "brush")
      .call(brush)
      .call(brush.move, x.range());

});

//create brush function redraw scatterplot with selection
function brushed() {
  var selection = d3.event.selection;
  x.domain(selection.map(x2.invert, x2));
  focus.selectAll(".dot")
        .attr("x", function(d) { return x(d.date) - pillWidth / 2; })
        .attr("y", function(d) { return y(d.price) - pillHeight / 2; })
  focus.select(".axis--x").call(xAxis);
}

function type(d) {
  d.date = parseDate(d.date);
  d.price = +d.price;
  return d;
}

</script>

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