Chart.js:网格线仅在数据集点上

Question

我创建了一个简单的图表：

const myChart = new Chart(document.getElementById('myChartChart').getContext('2d');, {
type: 'scatter',
data: {
datasets: [{
label: 'Dataset',
data: [{
x: -40,
y: 34,
}, {
x: -10,
y: 45,
}, {
x: 140,
y: 45,
}],
fill: true,
stepped: true,
}]
},
options: {
responsive: true,
scales: {
x: {
suggestedMin: -50,
suggestedMax: 150,
ticks: {
callback: function(value, index, values) {
return value + ' °C';
}
},
},
y: {
suggestedMin: 32,
suggestedMax: 46,
ticks: {
callback: function(value, index, values) {
return value + ' bar';
}
},
}
},
plugins: {
legend: {
display: false
}
}
}
});

Fiddle：https://jsfiddle.net/o6b97xL2

但我不喜欢在我的三个数据点上有静态的周期性网格线和标签。通过回调，我只能从网格中获得已定义的步骤。我如何才能实现这样的目标：

图片链接(您需要至少10个信誉才能发布图片(

Answer 1

您可以在两个轴上定义afterBuildTicks回调。在那里，您可以将轴记号替换为从data中提取的自己的记号。

请看一下您修改后的代码，看看它是如何工作的。

const data = [
{ x: -40, y: 34 }, 
{ x: -10, y: 45 },
{ x: 140, y: 45 }
];
myChart = new Chart('myChartChart', {
type: 'scatter',
data: {
datasets: [{
label: 'Dataset',
data: data,
fill: true,
stepped: true,
}]
},
options: {
responsive: true,
scales: {
x: {
suggestedMin: -50,
suggestedMax: 150,
afterBuildTicks: axis => axis.ticks = data.map(v => ({ value: v.x })),
ticks: {
callback: v => v + ' °C'
}
},
y: {
suggestedMin: 32,
suggestedMax: 46,
afterBuildTicks: axis => axis.ticks = data.map(v => ({ value: v.y })),
ticks: {
callback: v => v + ' bar'
}
}
},
plugins: {
legend: {
display: false
}
}
}
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.6.2/chart.min.js"></script>
<canvas id="myChartChart"></canvas>