Can not read property "__" of undefined - meteor

Question

I am currently working for my school project and using Meteor with AngularJs 1 and ES6. In one of my views I try to update some live data (with AngularCharts) every second which are currently randomly generated. I am new to the way of how Meteor and ES6 works, so I think a have a pretty easy error.
This is my code of the class from the view:
class View2 {
constructor($interval, $scope) {
'ngInject';
this.cardRow = [
{name: 'Drilling Heat', color: 'white', value: 0},
{name: 'Drilling Speed', color: 'white', value: 0},
{name: 'Milling Heat', color: 'white', value: 0},
{name: 'Milling Speed', color: 'white', value: 0}
];
this.type = ['bar', 'line', 'pie', 'doughnut', 'radar'];
this.chartRow = [
{
name: 'Chart1',
type: 'bar',
labels: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
series: ['Series A'],
data: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
datasetOverride: [{yAxisID: 'y-axis-1'}],
options: {
animation: false,
scales: {
yAxes: [
{
id: 'y-axis-1',
type: 'linear',
display: true,
position: 'left'
}]
}
}
},
{
name: 'Chart2',
type: 'line',
labels: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
series: ['Series A'],
data: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
datasetOverride: [{yAxisID: 'y-axis-1'}],
options: {
animation: false,
scales: {
yAxes: [
{
id: 'y-axis-1',
type: 'linear',
display: true,
position: 'left'
}]
}
}
}
];
$interval(this.update, 1000);
}
update() {
for (var i = 0; i < this.cardRow.length; i++) {
this.cardRow[i].value = Math.round((Math.random() * 10) * 10);
var value = this.cardRow[i].value;
switch (true) {
case (value > 80):
this.cardRow[i].color = 'red';
break;
case (value > 60):
this.cardRow[i].color = 'orange';
break;
case (value > 40):
this.cardRow[i].color = 'yellow';
break;
default:
this.cardRow[i].color = 'green';
break;
}
}
for (var y = 0; y < this.chartRow.length; y++) {
for (var z = 0; z < this.chartRow[y].data.length; z++) {
this.chartRow[y].data[z] = this.chartRow[y].data[z + 1];
}
this.chartRow[y].data[z - 1] = Math.round((Math.random() * 10) * 10);
}
}
}
The $interval should call the function "update" every second but then the variable is unknown. it throws an error like this:
TypeError: Cannot read property 'length' of undefined
at update (view2.js:74)
at callback (modules.js?hash=7db65c4…:46346)
at Scope.$eval (modules.js?hash=7db65c4…:51381)
at Scope.$digest (modules.js?hash=7db65c4…:51194)
at Scope.$apply (modules.js?hash=7db65c4…:51489)
at tick (modules.js?hash=7db65c4…:46336)
What can I do to solve this problem? And is there a way to use Meteor with the old Javascript Version?