D3 Examples - Random Points II

Random Points II

This is just a simple graph that plots random points in the continuous range [-50, 50]. Also shows tooltips on mouseover giving the point's coordinates.

Note: In order to get even width/height, the height has been set to a value that is outside of the range of the iframe in standard mode. This may be best viewed in fullscreen or side-by-side mode.

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<!DOCTYPE html>
<meta charset="utf-8">
<style> /* set the CSS */
.toolTip {
  pointer-events: none;
    position: absolute;
  display: none;
  width: 120px;
  height: auto;
  background: none repeat scroll 0 0 #ffffff;
  padding: 9px 14px 6px 14px;
  border-radius: 2px;
  text-align: center;
  line-height: 1.3;
  color: #5B6770;
  box-shadow: 0px 3px 9px rgba(0, 0, 0, .15);
}
.toolTip:after {
  content: "";
  width: 0;
  height: 0;
  border-left: 12px solid transparent;
  border-right: 12px solid transparent;
  border-top: 12px solid white;
  position: absolute;
  bottom: -10px;
  left: 50%;
  margin-left: -12px;
}  
.toolTip span {
    font-weight: 500;
  color: #081F2C;
}
</style>
<body>
<!-- load the d3.js library -->     
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>
​
// set the dimensions and margins of the graph
var margin = {top: 20, right: 20, bottom: 30, left: 50},
    width = 900 - margin.left - margin.right,
    height = 900 - margin.top - margin.bottom;
​
// set the ranges
var x = d3.scaleLinear().range([0, width]);
var y = d3.scaleLinear().range([height, 0]);
​
// 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 + ")");
​
var generate_random = function() {
  var dataset = []
  for (var i = 0; i < 20; i++) {
    var x = d3.randomUniform(-50,50)();
    var y = d3.randomUniform(-50,50)();
    dataset.push({"x": x, "y": y});
  }
  return dataset
}
​
var tooltip = d3.select("body").append("div").attr("class", "toolTip");
​
// Get the data
var data = generate_random()
​
// format the data
data.forEach(function(d) {
  d.x = +d.x;
  d.y = +d.y;
});
​
  // scale the range of the data
  x.domain([-50, 50]);
  y.domain([-50, 50]);
​
  // add the dots
  svg.selectAll("dot")
    .data(data)
    .enter().append("circle")
    .attr("r", 5)
    .attr("cx", function(d) { return x(d.x); })
    .attr("cy", function(d) { return y(d.y); })
    .on("mouseover", function(d) {
        console.log(d);
        tooltip
        .style("opacity", 1.0)
        .style("left", x(d.x) - 15 + "px")
        .style("top", y(d.y) - 25 + "px")
        .style("display", "inline-block")
        .html("(" + d.x.toFixed(3) + ", " + d.y.toFixed(3) + ")" )
    })
        .on("mouseout", function(d) {
        tooltip.style("opacity", 0.0);
    })
​
  // add the X Axis
  svg.append("g")
    .attr("transform", "translate(0," + height + ")")
    .call(d3.axisBottom(x));
​
  // add the Y Axis
  svg.append("g")
    .call(d3.axisLeft(y));
​
​
​
</script>
</body>
​
    