D3 Brush and Tooltip III

Example for Cooperative Brushing and Tooltips in D3.

Note that the brush layer is appended after the data, and therefore mouseover events do not trigger the tooltip. Only when you start brushing do the tooltips appear.

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

.point {
  fill: #2f225d;
  stroke: #afa2dc;
}

.selected {
  fill: #afa2dc;
  stroke: #2f225d;
}

.axis {
  font: 10px sans-serif;
}

p {
  font: 12px sans-serif;
  margin: 0 0 2px 0;
  padding: 0;
}

.clear-button {
  font: 14px sans-serif;
  cursor: pointer;
}

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

.brush .extent {
  stroke: #fff;
  fill-opacity: .125;
  shape-rendering: crispEdges;
}

</style>
<body>
<script src="https://d3js.org/d3.v3.min.js"></script>
<script>
d3.helper = {};

d3.helper = {};

d3.helper.tooltip = function(){
    var tooltipDiv;
    var bodyNode = d3.select('body').node();

function tooltip(selection){

selection.on('mouseover.tooltip', function(pD, pI){
            // Clean up lost tooltips
            d3.select('body').selectAll('div.tooltip').remove();
            // Append tooltip
            tooltipDiv = d3.select('body')
                           .append('div')
                           .attr('class', 'tooltip')
            var absoluteMousePos = d3.mouse(bodyNode);
            tooltipDiv.style({
                left: (absoluteMousePos[0] + 10)+'px',
                top: (absoluteMousePos[1] - 40)+'px',
                'background-color': '#d8d5e4',
                width: '65px',
                height: '30px',
                padding: '5px',
                position: 'absolute',
                'z-index': 1001,
                'box-shadow': '0 1px 2px 0 #656565'
            });

var first_line = '<p>X-Value: ' + pD.index + '</p>'
            var second_line = '<p>Y-Value: ' + pD.value + '</p>'

tooltipDiv.html(first_line + second_line)
        })
        .on('mousemove.tooltip', function(pD, pI){
            // Move tooltip
            var absoluteMousePos = d3.mouse(bodyNode);
            tooltipDiv.style({
                left: (absoluteMousePos[0] + 10)+'px',
                top: (absoluteMousePos[1] - 40)+'px'
            });
        })
        .on('mouseout.tooltip', function(pD, pI){
            // Remove tooltip
            tooltipDiv.remove();
        });

}

tooltip.attr = function(_x){
        if (!arguments.length) return attrs;
        attrs = _x;
        return this;
    };

tooltip.style = function(_x){
        if (!arguments.length) return styles;
        styles = _x;
        return this;
    };

return tooltip;
};

var data = [];
var values = [];
for (var i = 2; i <= 50; i++) {
    var val = Math.floor(Math.random() * (50 - 5 + 1) + 5);
    data.push({index: i, value: val});
    values.push(val);
}

var margin = {top: 20, right: 20, bottom: 60, left: 40},
    width = 960 - margin.left - margin.right,
    height = 500 - margin.top - margin.bottom;

var x = d3.scale.linear()
    .range([0, width])
    .domain([0, 50]);

var y = d3.scale.linear()
    .range([height, 0])
    .domain([0, d3.max(values) + 5]);

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

var yAxis = d3.svg.axis()
    .scale(y)
    .orient("left")
    .ticks(11);

var brush = d3.svg.brush()
    .x(x)
    .on("brush", brushmove)
    .on("brushend", brushend);

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 + ")");

svg.append("g")
    .attr("class", "x axis")
    .attr("clip-path", "url(#clip)")
    .attr("transform", "translate(0," + height + ")")
    .call(xAxis);

svg.append("g")
    .attr("class", "y axis")
    .call(yAxis);

points = svg.selectAll(".point")
    .data(data)
  .enter().append("circle")
    .attr("class", "point")
    .attr("clip-path", "url(#clip)")
    .attr("r", function(d){return Math.floor(Math.random() * (20 - 5 + 1) + 5);})
    .attr("cx", function(d) { return x(d.index); })
    .attr("cy", function(d) { return y(d.value); })
    .call(d3.helper.tooltip());

svg.append("g")
    .attr("class", "brush")
    .call(brush)
  .selectAll('rect')
    .attr('height', height);

svg.append("defs").append("clipPath")
    .attr("id", "clip")
  .append("rect")
    .attr("width", width)
    .attr("height", height + 20);

function brushmove() {
  var extent = brush.extent();
  points.classed("selected", function(d) {
    is_brushed = extent[0] <= d.index && d.index <= extent[1];
    return is_brushed;
  });
}

function brushend() {
  get_button = d3.select(".clear-button");
  if(get_button.empty() === true) {
    clear_button = svg.append('text')
      .attr("y", 460)
      .attr("x", 825)
      .attr("class", "clear-button")
      .text("Clear Brush");
  }

x.domain(brush.extent());

transition_data();
  reset_axis();

points.classed("selected", false);
  d3.select(".brush").call(brush.clear());

clear_button.on('click', function(){
    x.domain([0, 50]);
    transition_data();
    reset_axis();
    clear_button.remove();
  });
}

function transition_data() {
  svg.selectAll(".point")
    .data(data)
  .transition()
    .duration(500)
    .attr("cx", function(d) { return x(d.index); });
}

function reset_axis() {
  svg.transition().duration(500)
   .select(".x.axis")
   .call(xAxis);
}

</script>

Modified http://d3js.org/d3.v3.min.js to a secure url

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