如何将两个数组相乘并动态绘制成HighCharts？

Question

new to javascript. I am trying to make a new series in Highcharts using one already graphed series multiplied by another already graphed series. How do I add the new series with its own y-axis? I am using some base code that I have not done myself.

ChartOptions.Series[index].data holds an array of arrays: so for example :[1563480488000, 12.144] would be timestamp and datavalue for every data point in the series.

So I would want something like this: [1563480488000, 12.144] * [1563480488000, 1.0] = [1563480488000, 12.144]

that's 12.144*1.0, and the timestamp is kept.

dynamicChart is a new Highcharts.StockChart(chartOptions) its just away from the snippet I am working with. I've tried the following code.

 var voltSeries = chartOptions.series[0].data;
 var ampSeries = chartOptions.series[1].data;
 var wattSeries = [];
 for(var i = 0; i <= voltSeries.length; i++){
    var valu = chartOptions.series[1].data[i,1]*chartOptions.series[0].data[i,1];
    wattSeries[i,1] = valu;
    wattSeries[i,0] = valu;

}
  eval('window.console && console.log(voltSeries)');
  eval('window.console && console.log(wattSeries)');
   dynamicChart.addSeries({
       name: 'Watts',
       data: wattSeries 
    });
dynamicChart.redraw();    

the output of wattSeries is an Array of (2) [NaN, NaN] but It should be the timestamp and the multiplied value. and It seems like I cannot graph it no matter what I do.

Answer 1

The problem is incorrectly getting values from the array. For nested arrays you should use several parentheses: array[x][x]

var dynamicChart = Highcharts.chart('container', chartOptions);

var voltSeries = chartOptions.series[0].data,
    ampSeries = chartOptions.series[1].data,
    wattSeries = [],
    valu;

for (var i = 0; i < voltSeries.length; i++) {
    valu = voltSeries[i][1] * ampSeries[i][1];

    wattSeries.push([ampSeries[i][0], valu]);
}

dynamicChart.addSeries({
    name: 'Watts',
    data: wattSeries,
    yAxis: 1
});

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Live demo: http://jsfiddle.net/BlackLabel/vpzLou6r/

API Reference: https://api.highcharts.com/class-reference/Highcharts.Chart#addSeries