Google Charts LineChart example with updating.

google_linechart_update.js

// Google Chart Visualization Playground's LineChart Example
function drawVisualization() {
  // Create and populate the data table.
  var data = google.visualization.arrayToDataTable([
    ['x', 'Data 1', 'Data 2', 'Data 3'],
    [1,   1,        1,        0.5],
    [2,   2,        0.5,      1],
    [3,   4,        1,        0.5],
    [4,   8,        0.5,      1],
    [5,   7,        1,        0.5],
    [6,   7,        0.5,      1],
    [7,   8,        1,        0.5],
    [8,   4,        0.5,      1],
    [9,   2,        1,        0.5],
    [10,  3.5,      0.5,      1],
    [11,  3,        1,        0.5],
    [12,  3.5,      0.5,      1],
    [13,  1,        1,        0.5],
    [14,  1,        0.5,      1]
  ]);
  
  // Create and draw the visualization.
  var v = new google.visualization.LineChart(document.getElementById('visualization'));
  v.draw(data, {curveType: "function",
                width: 500, height: 400,
                vAxis: {maxValue: 10}});

  // Quick example of updating
  var i = 15;
  setInterval(function() {
  // Add a new row of data
  data.addRow([i++, Math.random()*10, Math.random()*10, Math.random()*10]);
  // Remove the oldest row of data
  data.removeRow(0);
  // Redraw the data
  v.draw(data, {curveType: "function",
                  width: 500, height: 400,
                  vAxis: {maxValue: 10}}); 
  }, 1000);
}