CODEWITHSUNDEEP
javascriptd3.js
Mike
Mike

Reputation: 7841

d3 update data and update graph

I have the following simple line in d3 but haven't an issue trying to figure out how to pass it data2 and update the line to reflect the change.

<!DOCTYPE html>
<html lang="en">
  <head>
    <title>D3 Line Chart Demo</title>
    <meta charset="utf-8" />    
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>

    <link rel="stylesheet" type="text/css" href="style.css">

    <script src="jquery.min.js" type="text/javascript" charset="utf-8"></script>
    <script src="d3.min.js" type="text/javascript" charset="utf-8"></script>
  <body>
    <button class="first last" onclick="transition()">
        Update
      </button>
    <div id="chart"></div>
  </body>

  <script>

    var data = [3, 7, 9, 1, 4, 6, 8, 2, 5];
    var data2 = [3, 7, 9, 1, 4, 6, 8, 2, 15];
    var width = 600;
    var height = 400;
    var max = d3.max(data);

    x = d3.scale.linear().domain([0, data.length - 1]).range([0, width]);
    y = d3.scale.linear().domain([0, max]).range([height, 0]);

    vis = d3.select('#chart')
        .style('margin', '20px auto')
        .style('width', "" + width + "px")
        .append('svg:svg')
        .attr('width', width)
        .attr('height', height)
        .attr('class', 'viz')
        .append('svg:g');

    vis.selectAll('path.line')
        .data([data])
        .enter()
        .append("svg:path")
        .attr("d", d3.svg.line().x(function(d, i) {
          return x(i);
        })
        .y(y));
  </script>
</html>

Upvotes: 35

Views: 43561

Answers (1)

Derek Ekins
Derek Ekins

Reputation: 11391

I am new to D3 but this is what I have found and I mainly figured this out from the sparklines example here.

Instead of drawing the line with this code:

vis.selectAll('path.line')
    .data([data])
    .enter()
    .append("svg:path")
    .attr("d", d3.svg.line().x(function(d, i) {return x(i); }).y(y));

generate the line separately:

 var line = d3.svg.line().x(function(d, i) { return x(i); }).y(y)

Then apply it to the data:

vis.selectAll('path.line')
    .data([data])
    .enter()
    .append("svg:path")
    .attr("d", line);

Then when you want to update the data you call:

 vis.selectAll("path")
   .data([data]) // set the new data
   .attr("d", line); // apply the new data values

The sparklines example also shows you how to animate it :)

Upvotes: 56

Related Questions