我的条形图工具提示存在一些问题。对于每个站点名称列，工具提示中应该显示相应的登机和下车值，但是，我得到了未定义的值，例如 here
这是我的代码:
<!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: orange;
}
.bar:hover {
fill: orangered ;
}
.x.axis path {
display: none;
}
.d3-tip {
line-height: 1;
font-weight: bold;
padding: 12px;
background: rgba(0, 0, 0, 0.8);
color: #fff;
border-radius: 2px;
}
/* Creates a small triangle extender for the tooltip */
.d3-tip:after {
box-sizing: border-box;
display: inline;
font-size: 10px;
width: 100%;
line-height: 1;
color: rgba(0, 0, 0, 0.8);
content: "\25BC";
position: absolute;
text-align: center;
}
/* Style northward tooltips differently */
.d3-tip.n:after {
margin: -1px 0 0 0;
top: 100%;
left: 0;
}
</style>
<body>
<script src="http://d3js.org/d3.v3.min.js"></script>
<script src="http://labratrevenge.com/d3-tip/javascripts/d3.tip.v0.6.3.js"></script>
<script>
var margin = {top: 40, right: 20, bottom: 300, left: 40},
width = 1250 - margin.left - margin.right,
height = 750 - margin.top - margin.bottom;
var x0 = d3.scale.ordinal()
.rangeRoundBands([0, width], .1);
var x1 = d3.scale.ordinal();
var y = d3.scale.linear()
.range([height, 0]);
var color = d3.scale.ordinal()
.range(["orange", "orangered"]);
var xAxis = d3.svg.axis()
.scale(x0)
.orient("bottom");
var yAxis = d3.svg.axis()
.scale(y)
.orient("left")
var tip = d3.tip()
.attr('class', 'd3-tip')
.offset([-10, 0])
.html(function(d) {
return "<strong>Stop:</strong> <span style='color:red'>" + d.stopname + "</span>" + "<br><br><strong>Mean no. of boardings:</strong> <span style='color:red'>" + d.meanboardings + "</span>"+ "<br><br><strong>Mean no. of alightings:</strong> <span style='color:red'>" + d.meanalightings + "</span>";
})
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 + ")");
svg.call(tip);
d3.tsv("data.tsv", function(d){
return {
stopname: d.stopname,
meanboardings: +d.meanboardings,
meanalightings: +d.meanalightings
};
}, function(error, data) {
console.log(data);
var dataset = d3.keys(data[0]).filter(function(key) { return key !== "stopname"
});
data.forEach(function(d) {
d.passengers = dataset.map(function(name) { return {name: name, value: +d[name]}; });
});
x0.domain(data.map(function(d) { return d.stopname; }));
x1.domain(dataset).rangeRoundBands([0, x0.rangeBand()]);
y.domain([0, d3.max(data, function(d) { return d3.max(d.passengers, function(d) { return d.value; }); })]);
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", "-.5em")
.attr("transform", function(d) {
return "rotate(-90)"
});
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("Mean no. of boardings and alightings");
var stopname = svg.selectAll(".stopname")
.data(data)
.enter().append("g")
.attr("class", "stopname")
.attr("transform", function(d) { return "translate(" + x0(d.stopname) + ",0)"; });
stopname.selectAll("rect")
.data(function(d) { return d.passengers; })
.enter().append("rect")
.attr("width", x1.rangeBand())
.attr("x", function(d) { return x1(d.name); })
.attr("y", function(d) { return y(d.value); })
.attr("height", function(d) { return height - y(d.value); })
.style("fill", function(d) { return color(d.name); })
.on('mouseover', tip.show)
.on('mouseout', tip.hide);
var legend = svg.selectAll(".legend")
.data(dataset.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; });
svg.selectAll(".bar")
.data(data)
.enter().append("rect")
.attr("class", "bar")
.attr("x", function(d) { return x(d.name); })
.attr("width", x.rangeBand())
.attr("y", function(d) { return y(d.value); })
.attr("height", function(d) { return height - y(d.value); })
});
function type(d) {
d.data = +d.data;
return d;
}
</script>
TSV 文件:
stopname maxboardings meanboardings minboardings varboardings maxalightings meanalightings minalightings varalightings maxload meanload minload varload noofbuses
The Boardwalk Terminal (3908) 7 2.571428571 0 6.952380952 0 0 0 0 7 2.571428571 0 6.952380952 7
Highview / Sugar Maple (3329) 2 0.333333333 0 0.666666667 1 0.166666667 0 0.166666667 6 3 0 6.4 6
Highview / Highview Pl (3330) 0 0 0 0 1 0.166666667 0 0.166666667 5 2.833333333 0 5.366666667 6
....
感谢任何帮助，谢谢!
最佳答案
您未定义，因为您使用未定义的值来生成工具提示文本。
在您的 html 函数中，您为每个矩形/条形获取的关联数据对象 d 具有以下格式:
{name: "meanlightings", value: <some_value>}
它不包含 stopname 属性，并且仅包含原始数据集中某一字段的值。
您必须将 html 回调重写为
.html(function(d) {
return "<strong>" + d.name + " :</strong> <span style='color:red'>" + d.value + "</span>";
})
但是，如果您想显示更多属性，则必须更改绑定(bind)到矩形的数据。
关于javascript - 显示未定义值的工具提示，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/35877729/