Pie Chart

Pie charts are perfect for showing proportions and part-to-whole relationships. Supports both pie and donut (ring) styles.

Basic Usage

<PieChart
  [data]="pieData"
  [legend]="legendConfig"
  [animation]="animationConfig"
  [drawHole]="true"
  [holeRadius]="45"
  [drawCenterText]="true"
  [centerText]="'Total'"
  [usePercentValues]="true">
</PieChart>

<pieChart
  data={pieData}
  legend={legendConfig}
  animation={animationConfig}
  drawHole={true}
  holeRadius={45}
  drawCenterText={true}
  centerText="Total"
  usePercentValues={true}
/>

<PieChart
  :data="pieData"
  :legend="legendConfig"
  :animation="animationConfig"
  :drawHole="true"
  :holeRadius="45"
  :drawCenterText="true"
  centerText="Total"
  :usePercentValues="true"
/>

<pieChart
  data={pieData}
  legend={legendConfig}
  animation={animationConfig}
  drawHole={true}
  holeRadius={45}
  drawCenterText={true}
  centerText="Total"
  usePercentValues={true}
/>

<pieChart
  data={pieData()}
  legend={legendConfig}
  animation={animationConfig}
  drawHole={true}
  holeRadius={45}
  drawCenterText={true}
  centerText="Total"
  usePercentValues={true}
/>

Data Format

import type { PieChartData, PieDataSet, PieDataEntry } from '@nstudio/ncharts';

const pieData: PieChartData = {
  dataSets: [
    {
      label: 'Market Share',
      values: [
        { value: 35, label: 'Product A' },
        { value: 25, label: 'Product B' },
        { value: 20, label: 'Product C' },
        { value: 12, label: 'Product D' },
        { value: 8, label: 'Others' },
      ],
      config: {
        colors: ['#F59E0B', '#EF4444', '#8B5CF6', '#3B82F6', '#6B7280'],
        sliceSpace: 3,
        selectionShift: 8,
      },
    },
  ],
};

PieDataEntry

Property	Type	Description
value	number	Slice value (required)
label	string	Slice label text

Simplified Values

You can also pass just numbers if you don't need labels:

values: [35, 25, 20, 12, 8]

DataSet Configuration

Slice Styling

Property	Type	Default	Description
colors	ChartColor[]	-	Colors for each slice
sliceSpace	number	0	Space between slices in dp
selectionShift	number	0	How far slice moves out when selected

Value Positioning

Property	Type	Default	Description
xValuePosition	ValuePosition	'INSIDE_SLICE'	Label position
yValuePosition	ValuePosition	'INSIDE_SLICE'	Value position

type ValuePosition = 'INSIDE_SLICE' | 'OUTSIDE_SLICE';

Value Lines (for outside positioning)

Property	Type	Description
valueLinePart1Length	number	Length of line segment 1
valueLinePart2Length	number	Length of line segment 2
valueLineColor	ChartColor	Line color
valueLineWidth	number	Line width
valueLinePart1OffsetPercentage	number	Offset from center
valueLineVariableLength	boolean	Auto-adjust line length

Chart Properties

Donut Configuration

Property	Type	Default	Description
drawHole	boolean	false	Enable donut mode
holeRadius	number	50	Hole radius as % of chart
holeColor	ChartColor	-	Hole background color
transparentCircleRadius	number	-	Transparent circle around hole
transparentCircleColor	ChartColor	-	Transparent circle color

Center Text

Property	Type	Description
drawCenterText	boolean	Show text in center
centerText	string	Center text content
centerTextColor	ChartColor	Text color
centerTextSize	number	Text size in dp

Slice Labels

Property	Type	Description
drawSliceText	boolean	Show labels on slices
entryLabelColor	ChartColor	Label text color
entryLabelTextSize	number	Label text size
usePercentValues	boolean	Show values as percentages

Interaction

Property	Type	Description
rotationEnabled	boolean	Allow rotation gesture
rotationAngle	number	Initial rotation angle
maxAngle	number	Max angle for display (default 360)
highlightPerTapEnabled	boolean	Enable tap selection

Complete Example

import type { 
  PieChartData, 
  ChartAnimation, 
  LegendConfig 
} from '@nstudio/ncharts';

// Market share data
const marketData: PieChartData = {
  dataSets: [
    {
      label: 'Market Share',
      values: [
        { value: 35, label: 'iOS Apps' },
        { value: 28, label: 'Android Apps' },
        { value: 18, label: 'Web Apps' },
        { value: 12, label: 'Desktop' },
        { value: 7, label: 'Other' },
      ],
      config: {
        colors: ['#3B82F6', '#10B981', '#F59E0B', '#8B5CF6', '#6B7280'],
        sliceSpace: 3,
        selectionShift: 10,
        drawValues: true,
        valueTextSize: 12,
        valueTextColor: '#FFFFFF',
        xValuePosition: 'INSIDE_SLICE',
        yValuePosition: 'INSIDE_SLICE',
      },
    },
  ],
};

// Animation
const animation: ChartAnimation = {
  durationX: 1400,
  durationY: 1400,
  easingX: 'EaseOutBounce',
};

// Legend
const legend: LegendConfig = {
  enabled: true,
  horizontalAlignment: 'CENTER',
  verticalAlignment: 'BOTTOM',
  orientation: 'HORIZONTAL',
  form: 'CIRCLE',
  textSize: 10,
};

Template

Standard Pie Chart

<PieChart
  #pieChart
  [data]="marketData"
  [animation]="animation"
  [legend]="legend"
  [drawHole]="false"
  [drawSliceText]="true"
  [usePercentValues]="true"
  [rotationEnabled]="true"
  [rotationAngle]="0"
  [highlightPerTapEnabled]="true"
  (select)="onSelect($event)"
  (deselect)="onDeselect()"
  class="h-80 w-full">
</PieChart>

Donut Chart

<PieChart
  [data]="marketData"
  [animation]="animation"
  [legend]="legend"
  [drawHole]="true"
  [holeRadius]="50"
  [transparentCircleRadius]="55"
  [holeColor]="'#FFFFFF'"
  [drawCenterText]="true"
  [centerText]="'Revenue\n$2.4M'"
  [centerTextColor]="'#374151'"
  [centerTextSize]="16"
  [usePercentValues]="true"
  class="h-80 w-full">
</PieChart>

import * as React from "react";
import { useState, useRef } from "react";
import type { PieChartData, ChartAnimation, LegendConfig, PieChart } from "@nstudio/ncharts";

export const PieChartDemo = () => {
  const pieChartRef = useRef<PieChart | null>(null);
  const [isDonut, setIsDonut] = useState(true);
  const [selectedData, setSelectedData] = useState(null);

  const marketData: PieChartData = {
    dataSets: [
      {
        label: 'Market Share',
        values: [
          { value: 35, label: 'Product A' },
          { value: 25, label: 'Product B' },
          { value: 20, label: 'Product C' },
          { value: 12, label: 'Product D' },
          { value: 8, label: 'Others' },
        ],
        config: {
          colors: ['#F59E0B', '#EF4444', '#8B5CF6', '#3B82F6', '#6B7280'],
          sliceSpace: 3,
          selectionShift: 8,
          drawValues: true,
          valueTextSize: 12,
          valueTextColor: '#FFFFFF',
        },
      },
    ],
  };

  return (
    <pieChart
      ref={pieChartRef}
      data={marketData}
      animation={{ durationX: 1400, durationY: 1400, easingX: 'EaseOutBounce' }}
      legend={{ enabled: true, horizontalAlignment: 'CENTER', verticalAlignment: 'BOTTOM' }}
      drawHole={isDonut}
      holeRadius={45}
      drawCenterText={isDonut}
      centerText="Total"
      usePercentValues={true}
      rotationEnabled={true}
      highlightPerTapEnabled={true}
      onSelect={(event) => setSelectedData(event.data)}
      onDeselect={() => setSelectedData(null)}
      className="h-80 w-full"
    />
  );
};

<script lang="ts" setup>
import { ref, computed } from 'vue';
import type { PieChartData, ChartSelectEvent } from '@nstudio/ncharts';

const selectedValue = ref('');
const isDonut = ref(false);

const chartData: PieChartData = {
  dataSets: [
    {
      label: 'Sales by Product',
      values: [
        { value: 35, label: 'Product A' },
        { value: 25, label: 'Product B' },
        { value: 20, label: 'Product C' },
        { value: 12, label: 'Product D' },
        { value: 8, label: 'Other' },
      ],
      config: {
        colors: ['#3B82F6', '#10B981', '#F59E0B', '#EF4444', '#8B5CF6'],
        sliceSpace: 2,
        selectionShift: 8,
        drawValues: true,
        valueTextSize: 12,
        valueTextColor: '#FFFFFF',
      },
    },
  ],
};

function handleValueSelected(event: ChartSelectEvent) {
  if (event.data) {
    selectedValue.value = `Value: ${event.data.y?.toFixed(0)}%`;
  }
}
</script>

<template>
  <PieChart
    :data="chartData"
    :animation="{ durationX: 1400, durationY: 1400, easingX: 'EaseOutBounce' }"
    :legend="{ enabled: true }"
    :drawHole="isDonut"
    :holeRadius="50"
    :drawCenterText="isDonut"
    centerText="Total"
    :usePercentValues="true"
    :rotationEnabled="true"
    :highlightPerTapEnabled="true"
    @select="handleValueSelected"
    class="h-80 w-full"
  />
</template>

<script lang="ts">
  import type { PieChartData, ChartSelectData } from '@nstudio/ncharts';

  let selectedData: ChartSelectData | null = null;
  let isDonut = true;

  const marketData: PieChartData = {
    dataSets: [
      {
        label: 'Market Share',
        values: [
          { value: 35, label: 'Product A' },
          { value: 25, label: 'Product B' },
          { value: 20, label: 'Product C' },
          { value: 12, label: 'Product D' },
          { value: 8, label: 'Others' },
        ],
        config: {
          colors: ['#F59E0B', '#EF4444', '#8B5CF6', '#3B82F6', '#6B7280'],
          sliceSpace: 3,
          selectionShift: 8,
          drawValues: true,
          valueTextSize: 12,
          valueTextColor: '#FFFFFF',
        },
      },
    ],
  };

  const legendConfig = { enabled: true, horizontalAlignment: 'CENTER', verticalAlignment: 'BOTTOM' };
  const animationConfig = { durationX: 1400, durationY: 1400, easingX: 'EaseOutBounce' };

  function handleSelect(event: CustomEvent) {
    selectedData = event.detail.data;
  }
</script>

<pieChart
  data={marketData}
  animation={animationConfig}
  legend={legendConfig}
  drawHole={isDonut}
  holeRadius={45}
  drawCenterText={isDonut}
  centerText="Total"
  usePercentValues={true}
  rotationEnabled={true}
  highlightPerTapEnabled={true}
  on:select={handleSelect}
  on:deselect={() => selectedData = null}
  class="h-80 w-full"
/>

import { createSignal } from 'solid-js';

export const PieChartDemo = () => {
  let pieChartRef;
  const [isDonut, setIsDonut] = createSignal(true);
  const [selectedData, setSelectedData] = createSignal(null);

  const marketData = () => ({
    dataSets: [
      {
        label: 'Market Share',
        values: [
          { value: 35, label: 'Product A' },
          { value: 25, label: 'Product B' },
          { value: 20, label: 'Product C' },
          { value: 12, label: 'Product D' },
          { value: 8, label: 'Others' },
        ],
        config: {
          colors: ['#F59E0B', '#EF4444', '#8B5CF6', '#3B82F6', '#6B7280'],
          sliceSpace: 3,
          selectionShift: 8,
          drawValues: true,
          valueTextSize: 12,
          valueTextColor: '#FFFFFF',
        },
      },
    ],
  });

  const legendConfig = { enabled: true, horizontalAlignment: 'CENTER', verticalAlignment: 'BOTTOM' };
  const animationConfig = { durationX: 1400, durationY: 1400, easingX: 'EaseOutBounce' };

  return (
    <pieChart
      ref={pieChartRef}
      data={marketData()}
      animation={animationConfig}
      legend={legendConfig}
      drawHole={isDonut()}
      holeRadius={45}
      drawCenterText={isDonut()}
      centerText="Total"
      usePercentValues={true}
      rotationEnabled={true}
      highlightPerTapEnabled={true}
      onSelect={(event) => setSelectedData(event.data)}
      onDeselect={() => setSelectedData(null)}
      class="h-80 w-full"
    />
  );
};

Half Pie (Semi-circle)

<PieChart
  [data]="marketData"
  [maxAngle]="180"
  [rotationAngle]="180"
  [drawHole]="true"
  [holeRadius]="40"
  class="h-48 w-full">
</PieChart>

<pieChart
  data={marketData}
  maxAngle={180}
  rotationAngle={180}
  drawHole={true}
  holeRadius={40}
  className="h-48 w-full"
/>

<PieChart
  :data="marketData"
  :maxAngle="180"
  :rotationAngle="180"
  :drawHole="true"
  :holeRadius="40"
  class="h-48 w-full"
/>

<pieChart
  data={marketData}
  maxAngle={180}
  rotationAngle={180}
  drawHole={true}
  holeRadius={40}
  class="h-48 w-full"
/>

<pieChart
  data={marketData()}
  maxAngle={180}
  rotationAngle={180}
  drawHole={true}
  holeRadius={40}
  class="h-48 w-full"
/>

Outside Labels Example

For charts with many small slices, place labels outside:

config: {
  colors: ['#3B82F6', '#10B981', '#F59E0B', '#8B5CF6', '#6B7280'],
  sliceSpace: 2,
  xValuePosition: 'OUTSIDE_SLICE',
  yValuePosition: 'OUTSIDE_SLICE',
  valueLinePart1Length: 0.4,
  valueLinePart2Length: 0.5,
  valueLineColor: '#9CA3AF',
  valueLineWidth: 1,
  valueLineVariableLength: true,
  drawValues: true,
  valueTextSize: 10,
  valueTextColor: '#374151',
}

Methods

Method	Parameters	Description
animate()	ChartAnimation	Trigger chart animation
highlightValues()	Highlight[]	Programmatically highlight slices
clearHighlights()	-	Clear all highlights
spin()	duration, degrees	Spin the chart

Events

Event	Payload	Description
select	ChartSelectEvent	Fired when slice is tapped
deselect	-	Fired when selection is cleared

Programmatic Control

@ViewChild('pieChart') chartRef!: ElementRef;

// Spin animation
spinChart(): void {
  const chart = this.chartRef.nativeElement;
  this.rotationAngle += 90;
}

// Animate in
animateChart(): void {
  const chart = this.chartRef.nativeElement;
  chart.animate({ 
    durationX: 1400, 
    durationY: 1400, 
    easingX: 'EaseInOutCubic' 
  });
}

See Also

• Animation Configuration
• Legend Configuration
• Styling Guide