javascript - D3饼图中的每个选择

Question

目前我正在尝试设计动态饼图，饼图的切片会根据随机生成的数据而变化。下面是代码。

var dataset = [
    { name: 'Smooth', percent: 40.00, class: 'custom-normal' },
    { name: 'Moderate', percent: 10.00, class: 'custom-warning' },
    { name: 'Heavy', percent: 50.00, class: 'custom-danger' }
];
var width = 960,
    height = 500,
    radius = Math.min(width, height) / 2; //Math.min return the smallest value between width and height (for optimization purposes)

var colorValues = d3.scaleOrdinal().domain(["Smooth", "Moderate", "Heavy"]).range(["#605A4C", "#ff9900", "#ff1a1a"]);
var percent = "percent"; //predefine the legend of dataset (the string index)
var category = "class";
var name = "name";

var pie = d3.pie()
    .value(function(d) { return d[percent]; })
    .sort(null)
    .padAngle(.02); //the gap

var arc = d3.arc()
    .innerRadius(radius - 100) //optimization
    .outerRadius(radius - 20); //optimization

var svg = d3.select("#chart")
    .append("svg")
    .attrs({
        width: width,
        height: height,
        class: "shadow"
    }).append("g")
    .attrs({
        transform: 'translate(' + width / 2 + ',' + height / 2 + ')'
    });
svg.append('g')
    .attrs({
        class: 'slices'
    });

var path = svg.select('.slices')
    .selectAll('path')
    .data(pie(dataset))
    .enter().append('path')
    .attrs({
        d: arc
    }).each(function(d, i) {
        this._current = d;
        console.log(this._current);
        console.log('okay!');
    }).attrs({
        class: function(d, i){
        return d[category];
        },
        fill: function(d, i) {
            console.log("this is color value" + colorValues());
            return colorValues(d[i]);
        }
    }); //initial details (this._current)


var randomGenerator = setInterval(function() {
    var data = dataset.map(function(d, i) {
        for (var key in d) {
            if (d[key] === "Smooth") {
                //console.log("smooth");
                dataset[0].percent = Math.floor(Math.random() * 100);
                //console.log(dataset[0].percent);
            } else if (d[key] === "Moderate") {
                dataset[1].percent = Math.floor(Math.random() * 100);
                //console.log(dataset[1].percent);
                //console.log("moderate");
            } else if (d[key] === "Heavy") {
                dataset[2].percent = Math.floor(Math.random() * 100);
                //console.log(dataset[2].percent);
                //console.log("heavy");
            }
        }

    });

}, 3000);


var timer = setInterval(function() {
    pie.value(function(d) {
        return d[percent];
    }); // change the value function
    path = path.data(pie(dataset)); // compute the new angles
    path.transition().duration(750).attrTween("d", arcTween); // redraw the arcs
}, 3000);


// Store the displayed angles in _current.
// Then, interpolate from _current to the new angles.
// During the transition, _current is updated in-place by d3.interpolate.
function arcTween(a) {
    var i = d3.interpolate(this._current, a);
    console.log(this._current);
    this._current = i(0);
    return function(t) {
        return arc(i(t));
    };
}

body {
    font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
    margin: auto;
    position: relative;
    width: 960px;
}

<meta charset="utf-8">
<div id="mydiv" class="widget">
    <div id="chart" class="Chart chart-container"></div>
</div>
<script src="https://d3js.org/d3.v4.js"></script>
<script src="https://d3js.org/d3-selection-multi.v0.4.min.js"></script>

请注意，每个切片的颜色并未根据我之前定义的进行缩放。即:var colorValues = d3.scaleOrdinal().domain(["Smooth", "Moderate", "Heavy"]).range(["#605A4C", "#ff9900", "#ff1a1a"]) ;。我认为这应该是选择问题，但是我对此一无所知。然而，类也是如此，它只获取 var dataset 中的第一行数据并应用于所有数据。

Answer 1

如果我没理解错的话，

通过 pie 函数推送您的数据，您正在更改您的数据。虽然您的初始结构是:

{ name: 'Smooth', percent: 40.00, class: 'custom-normal' }

通过 pie 函数运行此数据后，绑定(bind)到每个圆弧的数据具有以下结构:

{
  "data": {
    "name": "Heavy",
    "percent": 48,
    "class": "custom-danger"
  },
  "index": 2,
  "value": 50,
  "startAngle": 3.1515926535897933,
  "endAngle": 6.283185307179586,
  "padAngle": 0.02
}

在您的代码中，您基于此为楔形着色:

fill: function(d, i) {
    console.log("this is color value" + colorValues());
    return colorValues(d[i]);
}

function(d){} 中的d 指的是数据，因此它只是输入数据中的单个项目(绑定(bind)到特定弧的数据)，这是一个对象 - d[number] 的使用表明您预期一个数组。无论如何，每次运行此函数时，您都会得到 undefined。

而是访问所需数据的属性:name(我假设)并使用:

fill: function(d, i) {
    console.log("this is color value" + colorValues());
    return colorValues(d.data.name);
}

var dataset = [
    { name: 'Smooth', percent: 40.00, class: 'custom-normal' },
    { name: 'Moderate', percent: 10.00, class: 'custom-warning' },
    { name: 'Heavy', percent: 50.00, class: 'custom-danger' }
];
var width = 960,
    height = 500,
    radius = Math.min(width, height) / 2; //Math.min return the smallest value between width and height (for optimization purposes)

var colorValues = d3.scaleOrdinal().domain(["Smooth", "Moderate", "Heavy"]).range(["#605A4C", "#ff9900", "#ff1a1a"]);
var percent = "percent"; //predefine the legend of dataset (the string index)
var category = "class";
var name = "name";

var pie = d3.pie()
    .value(function(d) { return d[percent]; })
    .sort(null)
    .padAngle(.02); //the gap

var arc = d3.arc()
    .innerRadius(radius - 100) //optimization
    .outerRadius(radius - 20); //optimization

var svg = d3.select("#chart")
    .append("svg")
    .attrs({
        width: width,
        height: height,
        class: "shadow"
    }).append("g")
    .attrs({
        transform: 'translate(' + width / 2 + ',' + height / 2 + ')'
    });
svg.append('g')
    .attrs({
        class: 'slices'
    });

var path = svg.select('.slices')
    .selectAll('path')
    .data(pie(dataset))
    .enter().append('path')
    .attrs({
        d: arc
    }).each(function(d, i) {
        this._current = d;
        console.log(this._current);
        console.log('okay!');
    }).attrs({
        class: function(d, i){
        return d.data.class;
        },
        fill: function(d, i) {
            console.log("this is color value" + colorValues());
            return colorValues(d.data.name);
        }
    }); //initial details (this._current)


var randomGenerator = setInterval(function() {
    var data = dataset.map(function(d, i) {
        for (var key in d) {
            if (d[key] === "Smooth") {
                //console.log("smooth");
                dataset[0].percent = Math.floor(Math.random() * 100);
                //console.log(dataset[0].percent);
            } else if (d[key] === "Moderate") {
                dataset[1].percent = Math.floor(Math.random() * 100);
                //console.log(dataset[1].percent);
                //console.log("moderate");
            } else if (d[key] === "Heavy") {
                dataset[2].percent = Math.floor(Math.random() * 100);
                //console.log(dataset[2].percent);
                //console.log("heavy");
            }
        }

    });

}, 3000);


var timer = setInterval(function() {
    pie.value(function(d) {
        return d[percent];
    }); // change the value function
    path = path.data(pie(dataset)); // compute the new angles
    path.transition().duration(750).attrTween("d", arcTween); // redraw the arcs
}, 3000);


// Store the displayed angles in _current.
// Then, interpolate from _current to the new angles.
// During the transition, _current is updated in-place by d3.interpolate.
function arcTween(a) {
    var i = d3.interpolate(this._current, a);
    console.log(this._current);
    this._current = i(0);
    return function(t) {
        return arc(i(t));
    };
}

body {
    font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
    margin: auto;
    position: relative;
    width: 960px;
}

<meta charset="utf-8">
<div id="mydiv" class="widget">
    <div id="chart" class="Chart chart-container"></div>
</div>
<script src="https://d3js.org/d3.v4.js"></script>
<script src="https://d3js.org/d3-selection-multi.v0.4.min.js"></script>