AmCharts-使用dataprovider设置最大值轴

Question

I'm trying to set max value axis using dataprovider, since I'm dynamically loading data in my bar chart I need to see the "progress" on one of the bars compared to the one that is supposed to be the total.

How do I achieve this?

I' tried with:

"valueAxes": [
                {
                    "id": "ValueAxis-1",
                    "stackType": "regular",
                    "maximum": myDataProviderAttribute
                }

But no luck.

Any suggestion will be much apreciated.

Answer 1

I've submited a ticket to AmCharts support and got this feedback:

You can set max before the chart is initialized based on the data you have, inside addInitHandler. Here is an example for a simple column chart:

AmCharts.addInitHandler(function(chart) {

  // find data maximum:
  var min = chart.dataProvider[0].visits;
  for (var i in chart.dataProvider) {
    if (chart.dataProvider[i].visits > max) {
        max = chart.dataProvider[i].visits;
    }
  }
  // set axes max based on value above:
  chart.valueAxes[0].maximum = max  + 100;
  chart.valueAxes[0].strictMinMax = true;
});

You may need to use strictMinMax as above to enforce the value: https://docs.amcharts.com/3/javascriptcharts/ValueAxis#strictMinMax

Example of setting minimum inside addInitHandler:

https://codepen.io/team/amcharts/pen/b4be8cb4e3c073909860720e0909a876?editors=1010

If you refresh the data, or use live data, then before you animate or validate the chart to show the updated data, you should recalculate the max and, if you want the axis to change then use chart.valueAxes[0].maximum = max; where max is something you calculate based on data input.

Here is an example:

function loop() {
    var data = generateChartData();
    chart.valueAxes[0].maximum = max;

    // refresh data:
    chart.animateData(data, {
        duration: 1000,
        complete: function () {
            setTimeout(loop, 2000);
        }
    });
}

The lines above were used in this example:

https://codepen.io/team/amcharts/pen/d0d5d03cfdcc2cc256e28ec52ad8b95c/?editors=1010