Live Data Updates

Overview

amCharts 5 provides powerful methods for updating chart data in real-time. You can add new data points, remove old ones, and update existing values while maintaining smooth animations and transitions.

Adding New Data

Using push()

Add new data points to the end of the series:

import * as am5 from "@amcharts/amcharts5";
import * as am5xy from "@amcharts/amcharts5/xy";

const series = chart.series.push(am5xy.LineSeries.new(root, {
  xAxis: xAxis,
  yAxis: yAxis,
  valueYField: "value",
  valueXField: "date"
}));

// Add initial data
series.data.setAll([
  { date: new Date(2023, 0, 1).getTime(), value: 100 },
  { date: new Date(2023, 0, 2).getTime(), value: 150 }
]);

// Add a new data point
series.data.push({
  date: new Date(2023, 0, 3).getTime(),
  value: 180
});

Using unshift()

Add new data points to the beginning:

// Add data at the start
series.data.unshift({
  date: new Date(2022, 11, 31).getTime(),
  value: 90
});

Using insertIndex()

Insert data at a specific position:

// Insert at index 2
series.data.insertIndex(2, {
  date: new Date(2023, 0, 2, 12, 0).getTime(),
  value: 160
});

Removing Data

Using removeIndex()

Remove data at a specific index:

// Remove the first data point
series.data.removeIndex(0);

// Remove the last data point
const lastIndex = series.data.length - 1;
series.data.removeIndex(lastIndex);

Using shift() and pop()

Remove from start or end:

// Remove and return first item
const firstItem = series.data.shift();

// Remove and return last item
const lastItem = series.data.pop();

Using clear()

Remove all data:

// Clear all data
series.data.clear();

Real-Time Updates Example

Here’s a complete example that updates a chart every second:

import * as am5 from "@amcharts/amcharts5";
import * as am5xy from "@amcharts/amcharts5/xy";
import am5themes_Animated from "@amcharts/amcharts5/themes/Animated";

// Create root
const root = am5.Root.new("chartdiv");
root.setThemes([am5themes_Animated.new(root)]);

// Create chart
const chart = root.container.children.push(am5xy.XYChart.new(root, {
  panX: true,
  panY: true,
  wheelX: "panX",
  wheelY: "zoomX"
}));

// Create axes
const xAxis = chart.xAxes.push(am5xy.DateAxis.new(root, {
  maxDeviation: 0.5,
  baseInterval: { timeUnit: "day", count: 1 },
  renderer: am5xy.AxisRendererX.new(root, {}),
  tooltip: am5.Tooltip.new(root, {})
}));

const yAxis = chart.yAxes.push(am5xy.ValueAxis.new(root, {
  renderer: am5xy.AxisRendererY.new(root, {})
}));

// Create series
const series = chart.series.push(am5xy.LineSeries.new(root, {
  name: "Series",
  xAxis: xAxis,
  yAxis: yAxis,
  valueYField: "value",
  valueXField: "date",
  tooltip: am5.Tooltip.new(root, {
    labelText: "{valueY}"
  })
}));

// Generate initial data
let value = 100;
function generateData() {
  const data = [];
  let date = new Date();
  date.setDate(date.getDate() - 30);
  
  for (let i = 0; i < 30; i++) {
    value += Math.round((Math.random() < 0.5 ? 1 : -1) * Math.random() * 10);
    data.push({
      date: date.getTime(),
      value: value
    });
    date.setDate(date.getDate() + 1);
  }
  return data;
}

series.data.setAll(generateData());

// Update data every second
setInterval(function() {
  addData();
}, 1000);

function addData() {
  const lastDataItem = series.dataItems[series.dataItems.length - 1];
  const lastValue = lastDataItem.get("valueY");
  const lastDate = new Date(lastDataItem.get("valueX"));
  
  // Generate new value
  const newValue = lastValue + Math.round((Math.random() < 0.5 ? 1 : -1) * Math.random() * 5);
  const newDate = am5.time.add(lastDate, "day", 1).getTime();
  
  // Remove oldest data point
  series.data.removeIndex(0);
  
  // Add new data point
  series.data.push({
    date: newDate,
    value: newValue
  });
}

chart.appear(1000, 100);

Animating Live Updates

Create smooth transitions when adding new data:

function addData() {
  const lastDataItem = series.dataItems[series.dataItems.length - 1];
  const lastValue = lastDataItem.get("valueY");
  const lastDate = new Date(lastDataItem.get("valueX"));
  
  const newValue = lastValue + Math.round((Math.random() < 0.5 ? 1 : -1) * Math.random() * 5);
  const newDate = am5.time.add(lastDate, "day", 1).getTime();
  
  // Remove oldest
  series.data.removeIndex(0);
  
  // Add new
  series.data.push({
    date: newDate,
    value: newValue
  });
  
  // Animate the new data item
  const newDataItem = series.dataItems[series.dataItems.length - 1];
  
  // Animate value from old to new
  newDataItem.animate({
    key: "valueYWorking",
    to: newValue,
    from: lastValue,
    duration: 600,
    easing: am5.ease.linear
  });
  
  // Animate position
  const animation = newDataItem.animate({
    key: "locationX",
    to: 0.5,
    from: -0.5,
    duration: 600
  });
  
  // Update tooltip after animation
  if (animation) {
    const tooltip = xAxis.get("tooltip");
    if (tooltip && !tooltip.isHidden()) {
      animation.events.on("stopped", function() {
        xAxis.updateTooltip();
      });
    }
  }
}

Updating Existing Data

Modifying Values

Update data by modifying the data item:

// Access data items
const dataItems = series.dataItems;

// Update a specific data item
if (dataItems.length > 0) {
  const dataItem = dataItems[5];
  dataItem.set("valueY", 200);
  dataItem.set("valueYWorking", 200);
}

Replacing Data at Index

Replace an entire data point:

// Replace data at index 3
series.data.setIndex(3, {
  date: new Date(2023, 0, 4).getTime(),
  value: 250
});

Polling for Updates

Fetch new data from an API at regular intervals:

import * as am5 from "@amcharts/amcharts5";

const POLL_INTERVAL = 5000; // 5 seconds

async function pollData() {
  try {
    const response = await am5.net.load("https://api.example.com/latest");
    const newData = JSON.parse(response.response);
    
    // Add new data points
    newData.forEach(point => {
      series.data.push(point);
    });
    
    // Limit data to last 100 points
    while (series.data.length > 100) {
      series.data.removeIndex(0);
    }
  } catch (error) {
    console.error("Failed to fetch data:", error);
  }
}

// Start polling
const intervalId = setInterval(pollData, POLL_INTERVAL);

// Stop polling when needed
// clearInterval(intervalId);

WebSocket Updates

Update charts with data from WebSocket connections:

const socket = new WebSocket("wss://api.example.com/stream");

socket.onmessage = (event) => {
  const data = JSON.parse(event.data);
  
  // Add new data point
  series.data.push({
    date: data.timestamp,
    value: data.value
  });
  
  // Keep only last 50 points
  if (series.data.length > 50) {
    series.data.removeIndex(0);
  }
};

socket.onerror = (error) => {
  console.error("WebSocket error:", error);
};

// Close socket when done
// socket.close();

Multiple Series Updates

Update multiple series simultaneously:

const series1 = chart.series.push(am5xy.LineSeries.new(root, {
  xAxis: xAxis,
  yAxis: yAxis,
  valueYField: "value1",
  valueXField: "date"
}));

const series2 = chart.series.push(am5xy.LineSeries.new(root, {
  xAxis: xAxis,
  yAxis: yAxis,
  valueYField: "value2",
  valueXField: "date"
}));

function updateBothSeries() {
  const timestamp = new Date().getTime();
  
  // Update series 1
  series1.data.push({
    date: timestamp,
    value1: Math.random() * 100
  });
  
  // Update series 2
  series2.data.push({
    date: timestamp,
    value2: Math.random() * 100
  });
  
  // Remove old data from both
  if (series1.data.length > 50) {
    series1.data.removeIndex(0);
  }
  if (series2.data.length > 50) {
    series2.data.removeIndex(0);
  }
}

setInterval(updateBothSeries, 1000);

Performance Optimization

Batch Updates

For multiple updates, batch them together:

// Bad: Multiple individual updates
for (let i = 0; i < 100; i++) {
  series.data.push(newDataPoints[i]);  // Triggers 100 updates
}

// Good: Single batch update
const currentData = series.data.values;
const updatedData = [...currentData, ...newDataPoints];
series.data.setAll(updatedData);  // Single update

Limiting Data Points

Keep data size manageable:

const MAX_DATA_POINTS = 100;

function addDataPoint(newPoint) {
  series.data.push(newPoint);
  
  // Remove oldest if over limit
  if (series.data.length > MAX_DATA_POINTS) {
    series.data.removeIndex(0);
  }
}

Disabling Animations

For high-frequency updates, consider disabling animations:

const series = chart.series.push(am5xy.LineSeries.new(root, {
  xAxis: xAxis,
  yAxis: yAxis,
  valueYField: "value",
  valueXField: "date",
  interpolationDuration: 0  // Disable animation
}));

Cleaning Up

Remember to clean up intervals and connections:

let updateInterval;
let webSocket;

// Start updates
function startLiveUpdates() {
  updateInterval = setInterval(addData, 1000);
  webSocket = new WebSocket("wss://api.example.com/stream");
  webSocket.onmessage = handleWebSocketData;
}

// Stop updates
function stopLiveUpdates() {
  if (updateInterval) {
    clearInterval(updateInterval);
    updateInterval = null;
  }
  if (webSocket) {
    webSocket.close();
    webSocket = null;
  }
}

// Clean up when disposing the chart
root.events.on("disposed", () => {
  stopLiveUpdates();
});

Loading Data - Initial data loading methods
Processing Data - Transform data with DataProcessor
Animations - Control animation behavior

Getting Started

Core Concepts

Chart Types

XY Charts

Map Charts

Stock Charts

Customization

Data

Plugins

Advanced

Overview

Adding New Data

Using push()

Using unshift()

Using insertIndex()

Removing Data

Using removeIndex()

Using shift() and pop()

Using clear()

Real-Time Updates Example

Animating Live Updates

Updating Existing Data

Modifying Values

Replacing Data at Index

Polling for Updates

WebSocket Updates

Multiple Series Updates

Performance Optimization

Batch Updates

Limiting Data Points

Disabling Animations

Cleaning Up

Build docs developers (and LLMs) love

Getting Started

Core Concepts

Chart Types

XY Charts

Map Charts

Stock Charts

Customization

Data

Plugins

Advanced

Documentation Index

​Overview

​Adding New Data

​Using push()

​Using unshift()

​Using insertIndex()

​Removing Data

​Using removeIndex()

​Using shift() and pop()

​Using clear()

​Real-Time Updates Example

​Animating Live Updates

​Updating Existing Data

​Modifying Values

​Replacing Data at Index

​Polling for Updates

​WebSocket Updates

​Multiple Series Updates

​Performance Optimization

​Batch Updates

​Limiting Data Points

​Disabling Animations

​Cleaning Up

​Related Topics

Build docs developers (and LLMs) love

Overview

Adding New Data

Using push()

Using unshift()

Using insertIndex()

Removing Data

Using removeIndex()

Using shift() and pop()

Using clear()

Real-Time Updates Example

Animating Live Updates

Updating Existing Data

Modifying Values

Replacing Data at Index

Polling for Updates

WebSocket Updates

Multiple Series Updates

Performance Optimization

Batch Updates

Limiting Data Points

Disabling Animations

Cleaning Up

Related Topics