我有一个更新按钮可以将新的.csv数据加载到D3.s堆积条形图中。我的问题是，在更新时，它似乎使用两个数据集而不仅仅是新数据集。我认为这与我对update和selectAll的一些混淆有关，但我无法弄清楚如何替换而不是追加。这是我目前的代码：
<!DOCTYPE html>
<meta charset="utf-8">
<style>
body {
font: 10px sans-serif;
}
.axis path,
.axis line {
fill: none;
stroke: #000;
shape-rendering: crispEdges;
}
.bar {
fill: steelblue;
}
.x.axis path {
display: none;
}
</style>
<body>
<!-- <label><input type="checkbox"> Sort values</label> -->
<div id="option">
<input name="updateButton"
type="button"
value="Update"
onclick="updateData()" />
</div>
<script src="http://d3js.org/d3.v3.min.js"></script>
<script>
var margin = {top: 20, right: 20, bottom: 200, left: 40},
width = 960 - margin.left - margin.right,
height = 650 - margin.top - margin.bottom;
var x = d3.scale.ordinal()
.rangeRoundBands([0, width], .1);
var y = d3.scale.linear()
.rangeRound([height, 0]);
var color = d3.scale.ordinal()
.range(["#98abc5", "#8a89a6", "#7b6888", "#6b486b", "#a05d56", "#d0743c", "#ff8c00"]);
var xAxis = d3.svg.axis()
.scale(x)
.orient("bottom");
var yAxis = d3.svg.axis()
.scale(y)
.orient("left")
.tickFormat(d3.format(".2s"));
var svg = d3.select("body").append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
d3.csv("FinalData4.csv", function(error, data) {
color.domain(d3.keys(data[0]).filter(function(key) { return key !== "State"; }));
data.forEach(function(d) {
var y0 = 0;
d.ages = color.domain().map(function(name) { return {name: name, y0: y0, y1: y0 += +d[name]}; });
d.total = d.ages[d.ages.length - 1].y1;
});
//data.sort(function(a, b) { return b.total - a.total; });
x.domain(data.map(function(d) { return d.State; }));
y.domain([0, d3.max(data, function(d) { return d.total; })]);
// x-axis label
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(xAxis)
.selectAll("text")
.style("text-anchor", "end")
.attr("dx", "-.8em")
.attr("dy", ".15em")
.attr("transform", function(d) {
return "rotate(-65)"
});
// y-axis label
svg.append("g")
.attr("class", "y axis")
.call(yAxis)
.append("text")
.attr("transform", "rotate(-90)")
.attr("y", 6)
.attr("dy", ".71em")
.style("text-anchor", "end")
.text("USD in Millions");
// adds bars
var state = svg.selectAll(".state")
.data(data)
.enter().append("g")
.attr("class", "g")
.attr("transform", function(d) { return "translate(" + x(d.State) + ",0)"; });
state.selectAll("rect")
.data(function(d) { return d.ages; })
.enter().append("rect")
.attr("width", x.rangeBand())
.attr("y", function(d) { return y(d.y1); })
.attr("height", function(d) { return y(d.y0) - y(d.y1); })
.style("fill", function(d) { return color(d.name); });
// set up the legend
var legend = svg.selectAll(".legend")
.data(color.domain().slice().reverse())
.enter().append("g")
.attr("class", "legend")
.attr("transform", function(d, i) { return "translate(0," + i * 20 + ")"; });
legend.append("rect")
.attr("x", width - 18)
.attr("width", 18)
.attr("height", 18)
.style("fill", color);
legend.append("text")
.attr("x", width - 24)
.attr("y", 9)
.attr("dy", ".35em")
.style("text-anchor", "end")
.text(function(d) { return d; });
});
// ** Update data section (Called from the onclick)
function updateData() {
// Get the data again
d3.csv("FinalData2015.csv", function(error, data2) {
color.domain(d3.keys(data2[0]).filter(function(key) { return key !== "State"; }));
data2.forEach(function(d) {
var y0 = 0;
d.ages = color.domain().map(function(name) { return {name: name, y0: y0, y1: y0 += +d[name]}; });
d.total = d.ages[d.ages.length - 1].y1;
});
x.domain(data2.map(function(d) { return d.State; }));
y.domain([0, d3.max(data2, function(d) { return d.total; })]);
var tran = d3.select("body").transition();
// change x-axis label
tran.select(".x.axis")
.duration(1000)
.call(xAxis)
.selectAll("text")
.style("text-anchor", "end")
.attr("dx", "-.8em")
.attr("dy", ".15em")
.attr("transform", function(d) {
return "rotate(-65)"
});
// change the y-axis label
tran.select(".y.axis")
.duration(1000)
.call(yAxis);
// adds bars
var state = svg.selectAll(".State")
.data(data2)
.enter().append("g")
//.transition()
//.duration(1000)
.attr("class", "g")
.attr("transform", function(d) { return "translate(" + x(d.State) + ",0)"; });
var test = state.selectAll("rect")
.data(function(d) { return d.ages; })
.enter().append("rect")
.transition()
.duration(1000)
.attr("width", x.rangeBand())
.attr("y", function(d) { return y(d.y1); })
.attr("height", function(d) { return y(d.y0) - y(d.y1); })
.style("fill", function(d) { return color(d.name); });
});
}
</script>
</body>
更新：我将functionUpdateData（）代码更改为我当前的代码，因为我意识到它有一些垃圾。新代码具有x和y轴标签的工作转换，但仍然与上面描述的实际条形码相同。
答案 0 :(得分：1)
这是因为您没有在更新功能中使用更新和退出连接（请仔细阅读本文http://bost.ocks.org/mike/join/）。据我所知，您希望使用新的csv数据更新现有的csv数据，因为您需要更新当前的数据集。我将举例说明一个更简单的代码：
function updateData() {
//this is the new data that you are binding to some circles on the canvas
var circle = svg.selectAll("circle").data([200, 100, 50,10,5]);
//if there is new data, you get those new circles with the enter() method
var circleEnter = circle.enter().append("circle");
circleEnter.attr("cy", 60);
circleEnter.attr("cx", function(d, i) { return i * 100 + 30; });
circleEnter.attr("r", function(d) { return Math.sqrt(d); });
//------THIS IS THE PART YOU ARE MISSING------
//but the circles that already exist need an update. (check there is no enter() method here)
circle.attr("r", function(d) { return Math.sqrt(d); });
//also you need to remove the circles that don´t have a data binding.
circle.exit().remove();
}
所以我认为在你的代码中你必须写一些类似的东西：
var state = svg.selectAll(".state").data(data);
//the update data
state.attr("transform", function(d) { return "translate(" + x(d.State) + ",0)"; });