'Amcharts.isReady' is not working in angular6? - angular6

Question

I am using amchart in my angular6 app with the help of following tutorial
amchart3-angular
But I need to show the graph after loaded all it's properties.How can I check whether the graph is ready to load in angular6?I tried with 'isReady' property of amchart.But it shows following error.
Cannot read property 'isReady' of undefined
app.component.ts
chart: AmChart;
ngAfterViewInit() {
this.chart = this.AmCharts.makeChart('chartdiv', {
'type': 'gauge',
'theme': 'light',
'dataProvider': [],
'axes': [{
'axisColor': 'transparent',
'color': '#fff',
'endValue': 7,
'gridInside': true,
'inside': true,
'radius': '100%',
'valueInterval': 1,
'tickColor': '#fff',
'pivotRadius': '0%',
'id': 'axes1',
'topText': 'RPM',
'topTextFontSize': 9,
'topTextYOffset': -20,
'topTextColor': '#fff',
'bottomTextYOffset': -3,
'bottomTextColor': '#fff',
'minorTickLength': 16,
'tickLength': 22,
'tickThickness': 2,
'labelOffset': 5,
'bands': [{
'color': '#f91f1f',
'endValue': 7,
'innerRadius': '87%',
'startValue': 5
},
{
'color': '#e60000',
'endValue': 0,
'startValue': 0,
'alpha': 0.3,
'radius': '100%',
'innerRadius': '15%',
},
{
'color': '#e60000',
'endValue': 0,
'startValue': 0,
'alpha': 0.6,
'radius': '100%',
'innerRadius': '15%',
},
]
}, {
'axisColor': '#fff',
'color': 'black',
'axisThickness': 3,
'endValue': 140,
'radius': '45%',
'valueInterval': 20,
'tickColor': 'black',
'axisAlpha': '0',
'bottomText': 'km/h',
'bottomTextFontSize': 9,
'bottomTextYOffset': -15,
'bottomTextColor': 'black',
'labelOffset': 2,
'tickThickness': 1.2,
'bands': [{
'color': '#fff',
'alpha': 1,
'startValue': 0,
'endValue': 220,
'radius': '100%',
'innerRadius': '0'
}]
}],
'arrows': [{
'color': '#ff0000',
'innerRadius': '6.3%',
'radius': '40%',
'startWidth': 3,
'value': 0,
}, {
'color': '#ff0000',
'innerRadius': '46%',
'radius': '90%',
'startWidth': 8,
'value': 0
},
{
'color': '#111',
'innerRadius': '7%',
'radius': '0',
'startWidth': 0,
'value': 0,
'nailAlpha': 1,
'nailRadius': 10
}
],
'export': {
'enabled': true
}
});
}
app.component.html
<div id="chartdiv" [style.width.%]="100" [style.height.px]="400">
in the above code I created the chart and store it in a variable having type 'Amchart' and displayed it in template with the help of 'id'. When I run the app the chart take little amount of time to show it in template. So that I need to show the graph only after it's initialization.How can I solve this issue?