How to redraw the google chart after adding data rows?

 function drawChart() {


      data = new google.visualization.DataTable();
         data.addColumn('number', 'Time');
         data.addColumn('number', 'Emotion');
      rowlength=ID.length;
      for(i=0; i<rowlength;i++)
      {
         data.addRow([Number(ID[i]), PosPerc[i]-NegPerc[i] ]);
      }
         options = {
         title: 'Emotion Analysis',
         curveType: 'function',
         legend: {position: 'bottom' },
         colors: ['blue'],
         vAxis: {minValue:-100, maxValue:100},
         animation: { "startup":true,       duration: 1000,        easing: 'in'      }
       };
      view = new google.visualization.DataView(data);
      view.setRows(data.getSortedRows({column: 0, desc: true}));
       var chart = new google.visualization.LineChart(document.getElementById('curve_chart'));
       chart.draw(view, options);
      }

This is how I have created a line chart using Google Charts. Now. Instead of loading the entire data at first. I want to have a animation such that the line extends when we add each data row into it. I tried calling the chart.draw(data options) inside the for loop. But that didn't work.