How to format numbers in a percent pie chart?

Using one of the official demos for a simple pie chart, how can I reformat all percent numbers? Say, I want to have all numbers rounded. I tried anything from putting numberFormat properties on pretty much everything to global root.numberFormatter.set("numberFormat", "#,###"); to no avail. Any hints?

<!-- Styles -->
<style>
#chartdiv {
  width: 100%;
  height: 500px;
}
</style>

<!-- Resources -->
<script src="https://cdn.amcharts.com/lib/5/index.js"></script>
<script src="https://cdn.amcharts.com/lib/5/percent.js"></script>
<script src="https://cdn.amcharts.com/lib/5/themes/Animated.js"></script>

<!-- Chart code -->
<script>
am5.ready(function() {

// Create root element
// https://www.amcharts.com/docs/v5/getting-started/#Root_element
var root = am5.Root.new("chartdiv");


// Set themes
// https://www.amcharts.com/docs/v5/concepts/themes/
root.setThemes([
  am5themes_Animated.new(root)
]);


// Create chart
// https://www.amcharts.com/docs/v5/charts/percent-charts/pie-chart/
var chart = root.container.children.push(am5percent.PieChart.new(root, {
  layout: root.verticalLayout
}));


// Create series
// https://www.amcharts.com/docs/v5/charts/percent-charts/pie-chart/#Series
var series = chart.series.push(am5percent.PieSeries.new(root, {
  valueField: "value",
  categoryField: "category",
  numberFormatter: am5.NumberFormatter.new(root, {numberFormat: "###"}),
}));


// Set data
// https://www.amcharts.com/docs/v5/charts/percent-charts/pie-chart/#Setting_data
series.data.setAll([
  { value: 10, category: "One" },
  { value: 9, category: "Two" },
  { value: 6, category: "Three" },
  { value: 5, category: "Four" },
  { value: 4, category: "Five" },
  { value: 3, category: "Six" },
  { value: 1, category: "Seven" },
]);


// Play initial series animation
// https://www.amcharts.com/docs/v5/concepts/animations/#Animation_of_series
series.appear(1000, 100);

}); // end am5.ready()
</script>

<!-- HTML -->
<div id="chartdiv"></div>

Solution

As per the documentation, you can set the label text template of a series using this:

series.labels.template.set("text", 
    "{category}: [bold] {valuePercentTotal.formatNumber('0.00')}%[/] ({value})");

For the number format you can enter #. to get the rounded percentages. See the working snippet:

<!-- Styles -->
<style>
#chartdiv {
  width: 100%;
  height: 500px;
}
</style>

<!-- Resources -->
<script src="https://cdn.amcharts.com/lib/5/index.js"></script>
<script src="https://cdn.amcharts.com/lib/5/percent.js"></script>
<script src="https://cdn.amcharts.com/lib/5/themes/Animated.js"></script>

<!-- Chart code -->
<script>
am5.ready(function() {

// Create root element
// https://www.amcharts.com/docs/v5/getting-started/#Root_element
var root = am5.Root.new("chartdiv");


// Set themes
// https://www.amcharts.com/docs/v5/concepts/themes/
root.setThemes([
  am5themes_Animated.new(root)
]);


// Create chart
// https://www.amcharts.com/docs/v5/charts/percent-charts/pie-chart/
var chart = root.container.children.push(am5percent.PieChart.new(root, {
  layout: root.verticalLayout
}));


// Create series
// https://www.amcharts.com/docs/v5/charts/percent-charts/pie-chart/#Series
var series = chart.series.push(am5percent.PieSeries.new(root, {
  valueField: "value",
  categoryField: "category",
  numberFormatter: am5.NumberFormatter.new(root, {numberFormat: "###"}),
}));

series.labels.template.set("text", 
    "{category}: [bold] {valuePercentTotal.formatNumber('#.')}%[/] ({value})");
        
// Set data
// https://www.amcharts.com/docs/v5/charts/percent-charts/pie-chart/#Setting_data
series.data.setAll([
  { value: 10, category: "One" },
  { value: 9, category: "Two" },
  { value: 6, category: "Three" },
  { value: 5, category: "Four" },
  { value: 4, category: "Five" },
  { value: 3, category: "Six" },
  { value: 1, category: "Seven" },
]);


// Play initial series animation
// https://www.amcharts.com/docs/v5/concepts/animations/#Animation_of_series
series.appear(1000, 100);

}); // end am5.ready()
</script>

<!-- HTML -->
<div id="chartdiv"></div>