series.aggregate String|Function (default: "max")

The aggregate function to apply for date series.

This function is used when a category (an year, month, etc.) contains two or more points. The function return value is displayed instead of the individual points.

The supported values are:

• "avg" - the average of all values for the date period.
• "count" - the number of values for the date period.
• "max" - the highest value for the date period.
• "min" - the lowest value for the date period.
• "sum" - the sum of all values for the date period. Defaults to 0 if no data points are defined.
• "sumOrNull" - the sum of all values for the date period. Defaults to null if no data points are defined.
• "first" - the first value
• function(values, series, dataItems, category) - user-defined aggregate function. Returns single value or data item.
• object - (compound aggregate) Applicable to "candlestick", "boxPlot" and ohlc "series". Specifies the aggregate for each data item field.

Example - set the chart series aggregate

<div id="chart"></div>
<script>
$("#chart").kendoChart({
  categoryAxis: {
    categories: [
      new Date("2012/01/01"),
      new Date("2012/01/02"),
      new Date("2012/01/02")
    ],
    type: "date"
  },
  series: [{
      data: [1, 2, 3],
      aggregate: "avg"
  }]
});
</script>

Example - set the chart series aggregate using a function

<div id="chart"></div>
<script>
$("#chart").kendoChart({
  categoryAxis: {
    categories: [
      new Date("2012/01/01"),
      new Date("2012/01/02"),
      new Date("2012/01/02")
    ],
    type: "date"
  },
  series: [{
      data: [1, 2, 3],
      aggregate: function(values, series, dataItems, category) {
        // Two values with the same date(2 and 3), add them together and then divide them by the total number of values with the same category.
        let average = values.reduce((a, b) => a + b) / values.length;

        return average;
      }
  }]
});
</script>