Chart.js で　Xが不等間隔の折れ線グラフを描画

16925 ワード
chart.js 折れ線グラフ chart.js テキストリンク

作成した折れ線グラフです。

入力データ

data.json
[
{ "x": 0.0, "y": 10.2 },
{ "x": 0.9, "y": 4.7 }, 
{ "x": 1.2, "y": 5.1 }, 
{ "x": 1.5, "y": 6.1 }, 
{ "x": 2.2, "y": 4.3 }, 
{ "x": 3.5, "y": 6.2 }, 
{ "x": 4.2, "y": 4.8 }, 
{ "x": 4.7, "y": 5.8 }, 
{ "x": 15.2, "y": 3.2 }, 
{ "x": 18.2, "y": 5.2 }, 
{ "x": 22.5, "y": 7.5}
]

<!DOCTYPE html>
<head lang="ja">
<meta http-equiv="CONTENT-TYPE" content="text/html; charset=utf-8" />
<script src="https://code.jquery.com/jquery-3.3.1.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.3/Chart.min.js"></script>
<script src="scatter.js"></script>
<script src="draw_line_chart.js"></script>
</head>
<body>
    <canvas id="myChart" width="400" height="200"></canvas>
<hr />
Jan/18/2018<p />
</body>
scatter.js
// ----------------------------------------------------------------------
/*
    scatter.js

                        Jan/18/2018
*/
// ----------------------------------------------------------------------
jQuery (function ()
{
    const file_json = "data.json"

    jQuery.getJSON (file_json,function (data_aa)
        {
    draw_line_chart_proc ("myChart",data_aa,0,12)
        })
})

// ----------------------------------------------------------------------
draw_line_chart.js
// -----------------------------------------------------------------------
/*
    draw_line_chart.js

                        Jan/17/2018
*/
// -----------------------------------------------------------------------
function draw_line_chart_proc (id_chart,data_aa,ymin,ymax)
{
const options_aa = {
     legend: { display: false },
        scales: {
            xAxes: [{
                type: 'linear',
                position: 'bottom',
        ticks: { min: 0, max: 24, stepSize: 3}
        }],
            yAxes: [{
                type: 'linear',
                position: 'bottom',
        ticks: { min: ymin, max: ymax}
        }]
        }
    }


var ctx = jQuery("#" + id_chart)

var scatterChart = new Chart(ctx, {
    type: 'line',
    data: {
        datasets: [{
        tension: 0,
        fill: false,
        pointRadius: 0,
        borderWidth: 0,
        backgroundColor: "blue",
        borderColor: "blue",
        data: data_aa
        }]
        },
    options: options_aa
})

}

// -----------------------------------------------------------------------
function draw_character_xx (id_chart)
{
    var ctx = jQuery("#" + id_chart)[0].getContext('2d')

    ctx.font = "12px 'ＭＳ Ｐゴシック'";
    ctx.fillStyle = "black";
    ctx.fillText("時刻", 300, 15);
}

// -----------------------------------------------------------------------
function draw_character_yy (id_chart,label_aa,unit_aa)
{
    var ctx = jQuery("#" + id_chart)[0].getContext('2d')

    ctx.font = "12px 'ＭＳ Ｐゴシック'";
    ctx.fillStyle = "black";
    ctx.fillText(label_aa, 5, 15);
    ctx.fillText(unit_aa, 5, 35);

    ctx.font = "18px 'ＭＳ Ｐゴシック'";
    ctx.fillText(label_aa, 300, 25);
}

// -----------------------------------------------------------------------

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