Loop in order to generate data points in Javascript

问题

I am trying to generate an area graph for two (or more) products i.e. Mosquito Repellents and Liquid Soap. I am using the JavaScript library CanvasJS to do that. The problem is that I need approximately 2000 data points instead of 4 hardcoded here and the problem is that I am unable to generate a for loop for two (or more) products that will do this for me. Can anyone help me on how to create this loop?

var chart = new CanvasJS.Chart("chartContainer", {
    data: [{
        type: "area",
        name: "Mosquito Repellents",
        showInLegend: "true",
        dataPoints: [{
                y: 83450,
                label: "spring"
            }, {
                y: 51240,
                label: "summer"
            }, {
                y: 64120,
                label: "fall"
            }, {
                y: 71450,
                label: "winter"
            }

        ]
    }, {
        type: "area",
        name: "Liquid Soap",
        showInLegend: "true",
        dataPoints: [{
                y: 20140,
                label: "spring"
            }, {
                y: 30170,
                label: "summer"
            }, {
                y: 24410,
                label: "autumn"
            }, {
                y: 38120,
                label: "fall"
            }

        ]
    }]
});

回答1:

You can use the Math.random function and a function to get it done. The function takes two parameters to set the lower and upper limits of the random y value.

var mosquitoRepellentsDataPoints = generateDataPoints(10000, 40000),
    liquidSoapDataPoints = generateDataPoints(10000, 40000);

var chart = new CanvasJS.Chart("chartContainer", {
    data: [{
        type: "area",
        name: "Mosquito Repellents",
        showInLegend: "true",
        dataPoints: mosquitoRepellentsDataPoints
    }, {
        type: "area",
        name: "Liquid Soap",
        showInLegend: "true",
        dataPoints: liquidSoapDataPoints
    }]
});


function generateDataPoints(lowerLimit, upperLimit) {
    var i,
        arr = [],
        seasons = ['spring', 'summer', 'fall', 'winter'];

    for (i = 0; i < 2000; i++) {
        arr.push({
            y: lowerLimit + Math.round(Math.random() * (upperLimit - lowerLimit)),
            label: seasons[Math.floor(Math.random() * seasons.length)]
        });
    }
    return arr;
}

来源：https://stackoverflow.com/questions/30990834/loop-in-order-to-generate-data-points-in-javascript

标签

javascript

for-loop

canvasjs