Synchronized Charts in JavaScript

Download JavaScript Chart Samples

While rendering data across multiple charts, you can better visualize the same by using Synchronized Charts - where tooltip, crosshair & axis range are synced across charts. For example, if you zoom/pan any one of the charts, it'll automatically zoom/pan other charts. Same goes for ToolTip & Crosshair as well. Below example shows a Synchronized JavaScript Chart along with source code that you can run on your machine.

Try Editing The Code

window.onload = function () {
  var charts = [];
  var toolTip = {
    shared: true
  },
  legend = {
    cursor: "pointer",
    itemclick: function (e) {
      if (typeof (e.dataSeries.visible) === "undefined" || e.dataSeries.visible) {
        e.dataSeries.visible = false;
      } else {
        e.dataSeries.visible = true;
      }
      e.chart.render();
    }
  };  

  var systemDps = [], userDps=[], waitDps = [], buffersDps = [], cacheDps = [], usedDps=[], inboundDps = [], outboundDps = [], writeDps = [], readDps = [];

  var cpuChartOptions = {
    animationEnabled: true,
    theme: "light2", // "light1", "light2", "dark1", "dark2"
    title:{
      text: "CPU Utilization"
    },
    toolTip: toolTip,
    axisY: {
      valueFormatString: "#0.#%",
    },
    legend: legend,
    data: [{
      type: "splineArea", 
      showInLegend: "true",
      name: "User",
      yValueFormatString: "#0.#%",
      color: "#64b5f6",
      xValueType: "dateTime",
      xValueFormatString: "DD MMM YY HH:mm",
      legendMarkerType: "square",
      dataPoints: userDps
    },{
      type: "splineArea", 
      showInLegend: "true",
      name: "System",
      yValueFormatString: "#0.#%",
      color: "#2196f3",
      xValueType: "dateTime",
      xValueFormatString: "DD MMM YY HH:mm",
      legendMarkerType: "square",
      dataPoints: systemDps
    },{
      type: "splineArea", 
      showInLegend: "true",
      name: "Wait",
      yValueFormatString: "#0.#%",
      color: "#1976d2",
      xValueType: "dateTime",
      xValueFormatString: "DD MMM YY HH:mm",
      legendMarkerType: "square",
      dataPoints: waitDps
    }]
  };
  var memoryChartOptions = {
    animationEnabled: true,
    theme: "light2",
    title:{
      text: "Memory Usage"
    },
    axisY: {
      suffix: " GB"
    },
    toolTip: toolTip,
    legend: legend,
    data: [{
      type: "splineArea", 
      showInLegend: "true",
      name: "Cache",
      color: "#e57373",
      xValueType: "dateTime",
      xValueFormatString: "DD MMM YY HH:mm",
      yValueFormatString: "#.## GB",
      legendMarkerType: "square",
      dataPoints: cacheDps
    },{
      type: "splineArea", 
      showInLegend: "true",
      name: "Buffers",
      color: "#f44336",
      xValueType: "dateTime",
      xValueFormatString: "DD MMM YY HH:mm",
      yValueFormatString: "#.## GB",
      legendMarkerType: "square",
      dataPoints: buffersDps
    },{
      type: "splineArea", 
      showInLegend: "true",
      name: "Used",
      color: "#d32f2f",
      xValueType: "dateTime",
      xValueFormatString: "DD MMM YY HH:mm",
      yValueFormatString: "#.## GB",
      legendMarkerType: "square",
      dataPoints: usedDps
    }]
  }
  var networkChartOptions = {
    animationEnabled: true,
    theme: "light2",
    title:{
      text: "Network Traffic"
    },
    axisY: {
      suffix: " Kb/s"
    },
    toolTip: toolTip,
    legend: legend,
    data: [{
      type: "splineArea", 
      showInLegend: "true",
      name: "Outbound",
      color: "#81c784",
      xValueType: "dateTime",
      xValueFormatString: "DD MMM YY HH:mm",
      yValueFormatString: "#.## Kb/s",
      legendMarkerType: "square",
      dataPoints: outboundDps
    },{
      type: "splineArea", 
      showInLegend: "true",
      name: "Inbound",
      color: "#388e3c",
      xValueType: "dateTime",
      xValueFormatString: "DD MMM YY HH:mm",
      yValueFormatString: "#.## Kb/s",
      legendMarkerType: "square",
      dataPoints: inboundDps
    }]
  }
  var diskChartOptions = {
    animationEnabled: true,
    theme: "light2",
    title:{
      text: "Disk I/O (IOPS)"
    },
    axisY: {},
    toolTip: toolTip,
    legend: legend,
    data: [{
      type: "splineArea", 
      showInLegend: "true",
      name: "Write",
      color: "#ffb74d",
      xValueType: "dateTime",
      xValueFormatString: "DD MMM YY HH:mm",
      yValueFormatString: "#.## ops/second",
      legendMarkerType: "square",
      dataPoints: writeDps
    },{
      type: "splineArea", 
      showInLegend: "true",
      name: "Read",
      color: "#f57c00",
      xValueType: "dateTime",
      xValueFormatString: "DD MMM YY HH:mm",
      yValueFormatString: "#.## ops/second",
      legendMarkerType: "square",
      dataPoints: readDps
    }]
  }

  charts.push(new CanvasJS.Chart("chartContainer1", cpuChartOptions));
  charts.push(new CanvasJS.Chart("chartContainer2", memoryChartOptions));
  charts.push(new CanvasJS.Chart("chartContainer3", networkChartOptions));
  charts.push(new CanvasJS.Chart("chartContainer4", diskChartOptions));

  $.get("https://canvasjs.com/data/gallery/javascript/server-matrics.json", function(data) {
    for (var i = 1; i < data.length; i++) {
      systemDps.push({x: parseInt(data[i].time), y: parseFloat(data[i].system)});
      userDps.push({x: parseInt(data[i].time), y: parseFloat(data[i].user)});
      waitDps.push({x: parseInt(data[i].time), y: parseFloat(data[i].wait)});
      buffersDps.push({x: parseInt(data[i].time), y: parseFloat(data[i].buffers)});
      cacheDps.push({x: parseInt(data[i].time), y: parseFloat(data[i].cache)});
      usedDps.push({x: parseInt(data[i].time), y: parseFloat(data[i].used)});
      inboundDps.push({x: parseInt(data[i].time), y: parseFloat(data[i].inbound)});
      outboundDps.push({x: parseInt(data[i].time), y: parseFloat(data[i].outbound)});
      writeDps.push({x: parseInt(data[i].time), y: parseFloat(data[i].write)});
      readDps.push({x: parseInt(data[i].time), y: parseFloat(data[i].read)});
    }
    for( var i = 0; i < charts.length; i++){
      charts[i].options.axisX = {
        labelAngle: 0,
        crosshair: {
          enabled: true,
          snapToDataPoint: true,
          valueFormatString: "HH:mm"
        }
      }
    }

    syncCharts(charts, true, true, true); // syncCharts(charts, syncToolTip, syncCrosshair, syncAxisXRange)

    for( var i = 0; i < charts.length; i++){
      charts[i].render();
    }

  });  

  function syncCharts(charts, syncToolTip, syncCrosshair, syncAxisXRange) {

    if(!this.onToolTipUpdated){
      this.onToolTipUpdated = function(e) {
        for (var j = 0; j < charts.length; j++) {
          if (charts[j] != e.chart)
            charts[j].toolTip.showAtX(e.entries[0].xValue);
        }
      }
    }

    if(!this.onToolTipHidden){
      this.onToolTipHidden = function(e) {
        for( var j = 0; j < charts.length; j++){
          if(charts[j] != e.chart)
            charts[j].toolTip.hide();
        }
      }
    }

    if(!this.onCrosshairUpdated){
      this.onCrosshairUpdated = function(e) {
        for(var j = 0; j < charts.length; j++){
          if(charts[j] != e.chart)
            charts[j].axisX[0].crosshair.showAt(e.value);
        }
      }
    }

    if(!this.onCrosshairHidden){
      this.onCrosshairHidden =  function(e) {
        for( var j = 0; j < charts.length; j++){
          if(charts[j] != e.chart)
            charts[j].axisX[0].crosshair.hide();
        }
      }
    }

    if(!this.onRangeChanged){
      this.onRangeChanged = function(e) {
        for (var j = 0; j < charts.length; j++) {
          if (e.trigger === "reset") {
            charts[j].options.axisX.viewportMinimum = charts[j].options.axisX.viewportMaximum = null;
            charts[j].options.axisY.viewportMinimum = charts[j].options.axisY.viewportMaximum = null;
            charts[j].render();
          } else if (charts[j] !== e.chart) {
            charts[j].options.axisX.viewportMinimum = e.axisX[0].viewportMinimum;
            charts[j].options.axisX.viewportMaximum = e.axisX[0].viewportMaximum;
            charts[j].render();
          }
        }
      }
    }

    for(var i = 0; i < charts.length; i++) { 

      //Sync ToolTip
      if(syncToolTip) {
        if(!charts[i].options.toolTip)
          charts[i].options.toolTip = {};

        charts[i].options.toolTip.updated = this.onToolTipUpdated;
        charts[i].options.toolTip.hidden = this.onToolTipHidden;
      }

      //Sync Crosshair
      if(syncCrosshair) {
        if(!charts[i].options.axisX)
          charts[i].options.axisX = { crosshair: { enabled: true }};
		
        charts[i].options.axisX.crosshair.updated = this.onCrosshairUpdated; 
        charts[i].options.axisX.crosshair.hidden = this.onCrosshairHidden; 
      }

      //Sync Zoom / Pan
      if(syncAxisXRange) {
        charts[i].options.zoomEnabled = true;
        charts[i].options.rangeChanged = this.onRangeChanged;
      }
    }
  }  

}

Chart Customizations

In the above example, we are using below events and methods.
Chart - rangeChanging, rangeChanged
ToolTip - updated, hidden, showAtX, hide
Crosshair - updated, hidden, showAt, hide