title: $(...).getContext("2d") is not a function when using chart.js
body: <p>i'm using nodejs and jade view engine. i want to load a chart in my page using chart.js i added the jquery and chart.js library but it still give my an error by title $(...).getContext("2d") is not a function.
  please help me with this question thanks .</p>
  
  <pre><code>$(document).ready(function(){
  var ctx = $("#myChart").getContext("2d");
  var myChart = new Chart(ctx, {
  type: 'bar',
  data: {
      labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
      datasets: [{
          label: '# of Votes',
          data: [12, 19, 3, 5, 2, 3],
          backgroundColor: [
              'rgba(255, 99, 132, 0.2)',
              'rgba(54, 162, 235, 0.2)',
              'rgba(255, 206, 86, 0.2)',
              'rgba(75, 192, 192, 0.2)',
              'rgba(153, 102, 255, 0.2)',
              'rgba(255, 159, 64, 0.2)'
          ],
          borderColor: [
              'rgba(255,99,132,1)',
              'rgba(54, 162, 235, 1)',
              'rgba(255, 206, 86, 1)',
              'rgba(75, 192, 192, 1)',
              'rgba(153, 102, 255, 1)',
              'rgba(255, 159, 64, 1)'
          ],
          borderWidth: 1
      }]
  },
  options: {
      scales: {
          yAxes: [{
              ticks: {
                  beginAtZero:true
              }
          }]
          }
      }
  });
  });
  </code></pre>