如何为给定实时数据计算angular6中特定列的动态和

Question

我已经创建了一个角度数据表。现在，我试图基于搜索过滤器明智地求和列，但它不起作用。我没有找到合适的解决方案。谁能指导我？预先感谢

    $(document).ready(function() {
            $('#example').dataTable( {
              "fnFooterCallback": function ( nRow, aaData, iDataStart, iDataEnd ) {
                /* Calculate the total market share for all browsers in this table (ie inc. outside
                 * the pagination
                 */
                var total = 0;
                for ( var i=0 ; i<aaData.length ; i++ )
                {
                  total+= aaData[i][8]*1;
                }

                /* Calculate the market share for browsers on this page */
                var value = 0;
                for ( var i=iDataStart ; i<iDataEnd ; i++ )
                {
                  value += aaData[i][8]*1;
                }

                /* Modify the footer row to match what we want */
                var nCells = nRow.getElementsByTagName('th');
                nCells[1].innerHTML = parseInt(value * 100)/100 +
                  '% ('+ parseInt(total * 100)/100 +'% total)';
              }
            } );
          } );