A Pen by Secret Sam.

D3-REaltime-chart-.markdown

D3 REaltime chart

Forked from Ajay Patel's Pen D3 REaltime chart .

A Pen by A Non Ymous on CodePen.

License.

script.js

Array.prototype.max = function() {
  return Math.max.apply(null, this);
};

Array.prototype.min = function() {
  return Math.min.apply(null, this);
};

var n = 40,
    random = d3.random.normal(0, .2),
    data = d3.range(n).map(random);
 
var margin = {top: 20, right: 20, bottom: 20, left: 40},
    width = 960 - margin.left - margin.right,
    height = 500 - margin.top - margin.bottom;
 
var x = d3.scale.linear()
    .domain([0, n - 1])
    .range([0, width]);
 
var y = d3.scale.linear()
    .domain([-1, 1])
    .range([height, 0]);
 
var line = d3.svg.line()
    .x(function(d, i) { return x(i); })
    .y(function(d, i) { return y(d); });
 
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("defs").append("clipPath")
    .attr("id", "clip")
  .append("rect")
    .attr("width", width)
    .attr("height", height);
 
var xAxisBase = svg.append("g")
    .attr("class", "x axis")
    .attr("transform", "translate(0," + y(0) + ")");

xAxisBase.call(d3.svg.axis().scale(x).orient("bottom"));
 
var yAxisBase = svg.append("g")
    .attr("class", "y axis");
yAxisBase.call(d3.svg.axis().scale(y).orient("left"));
 
var path = svg.append("g")
    .attr("clip-path", "url(#clip)")
  .append("path")
    .datum(data)
    .attr("class", "line")
    .attr("d", line);
 
tick();
 
function tick() {
 
  // push a new data point onto the back
  data.push(random() * 50 + 1);
 
  // redraw the line, and slide it to the left
  path
      .attr("d", line)
      .attr("transform", null)
    .transition()
      .duration(500)
      .ease("linear")
      .attr("transform", "translate(" + x(-1) + ",0)")
      .each("end", tick);
  
  x = d3.scale.linear()
    .domain([0, n - 1])
    .range([0, width]);
  
  y = d3.scale.linear()
    .domain([data.min(), data.max()])
    .range([height, 0]);
  
  xAxisBase.call(d3.svg.axis().scale(x).orient("bottom"))
  yAxisBase.call(d3.svg.axis().scale(y).orient("left"));
 
  // pop the old data point off the front
  data.shift();
 
}

style.css

svg {
  font: 10px sans-serif;
}
 
.line {
  fill: none;
  stroke: #000;
  stroke-width: 1.5px;
}
 
.axis path,
.axis line {
  fill: none;
  stroke: #000;
  shape-rendering: crispEdges;
}