对于这个工作示例（参见Multiseries line chart with mouseover tooltip），我还需要在圆圈旁边显示x轴值（而不仅仅是y值）。
如何实现这一目标？
<!DOCTYPE html>
<html>
<head>
<script data-require="d3@3.5.3" data-semver="3.5.3" src="//cdnjs.cloudflare.com/ajax/libs/d3/3.5.3/d3.js"></script>
<style>
body {
font: 10px sans-serif;
}
.axis path,
.axis line {
fill: none;
stroke: #000;
shape-rendering: crispEdges;
}
.x.axis path {
display: none;
}
.line {
fill: none;
stroke: steelblue;
stroke-width: 1.5px;
}
</style>
</head>
<body>
<script>
var myData = "date New York San Francisco Austin\n\
20111001 63.4 62.7 72.2\n\
20111002 58.0 59.9 67.7\n\
20111003 53.3 59.1 69.4\n\
20111004 55.7 58.8 68.0\n\
20111005 64.2 58.7 72.4\n\
20111006 58.8 57.0 77.0\n\
20111007 57.9 56.7 82.3\n\
20111008 61.8 56.8 78.9\n\
20111009 69.3 56.7 68.8\n\
20111010 71.2 60.1 68.7\n\
20111011 68.7 61.1 70.3\n\
20111012 61.8 61.5 75.3\n\
20111013 63.0 64.3 76.6\n\
20111014 66.9 67.1 66.6\n\
20111015 61.7 64.6 68.0\n\
20111016 61.8 61.6 70.6\n\
20111017 62.8 61.1 71.1\n\
20111018 60.8 59.2 70.0\n\
20111019 62.1 58.9 61.6\n\
20111020 65.1 57.2 57.4\n\
20111021 55.6 56.4 64.3\n\
20111022 54.4 60.7 72.4\n";
var margin = {
top: 20,
right: 80,
bottom: 30,
left: 50
},
width = 500 - margin.left - margin.right,
height = 500 - margin.top - margin.bottom;
var parseDate = d3.time.format("%Y%m%d").parse;
var x = d3.time.scale()
.range([0, width]);
var y = d3.scale.linear()
.range([height, 0]);
var color = d3.scale.category10();
var xAxis = d3.svg.axis()
.scale(x)
.orient("bottom");
var yAxis = d3.svg.axis()
.scale(y)
.orient("left");
var line = d3.svg.line()
.interpolate("basis")
.x(function(d) {
return x(d.date);
})
.y(function(d) {
return y(d.temperature);
});
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 + ")");
var data = d3.tsv.parse(myData);
color.domain(d3.keys(data[0]).filter(function(key) {
return key !== "date";
}));
data.forEach(function(d) {
d.date = parseDate(d.date);
});
var cities = color.domain().map(function(name) {
return {
name: name,
values: data.map(function(d) {
return {
date: d.date,
temperature: +d[name]
};
})
};
});
x.domain(d3.extent(data, function(d) {
return d.date;
}));
y.domain([
d3.min(cities, function(c) {
return d3.min(c.values, function(v) {
return v.temperature;
});
}),
d3.max(cities, function(c) {
return d3.max(c.values, function(v) {
return v.temperature;
});
})
]);
var legend = svg.selectAll('g')
.data(cities)
.enter()
.append('g')
.attr('class', 'legend');
legend.append('rect')
.attr('x', width - 20)
.attr('y', function(d, i) {
return i * 20;
})
.attr('width', 10)
.attr('height', 10)
.style('fill', function(d) {
return color(d.name);
});
legend.append('text')
.attr('x', width - 8)
.attr('y', function(d, i) {
return (i * 20) + 9;
})
.text(function(d) {
return d.name;
});
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(xAxis);
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("Temperature (ºF)");
var city = svg.selectAll(".city")
.data(cities)
.enter().append("g")
.attr("class", "city");
city.append("path")
.attr("class", "line")
.attr("d", function(d) {
return line(d.values);
})
.style("stroke", function(d) {
return color(d.name);
});
city.append("text")
.datum(function(d) {
return {
name: d.name,
value: d.values[d.values.length - 1]
};
})
.attr("transform", function(d) {
return "translate(" + x(d.value.date) + "," + y(d.value.temperature) + ")";
})
.attr("x", 3)
.attr("dy", ".35em")
.text(function(d) {
return d.name;
});
var mouseG = svg.append("g")
.attr("class", "mouse-over-effects");
mouseG.append("path") // this is the black vertical line to follow mouse
.attr("class", "mouse-line")
.style("stroke", "black")
.style("stroke-width", "1px")
.style("opacity", "0");
var lines = document.getElementsByClassName('line');
var mousePerLine = mouseG.selectAll('.mouse-per-line')
.data(cities)
.enter()
.append("g")
.attr("class", "mouse-per-line");
mousePerLine.append("circle")
.attr("r", 7)
.style("stroke", function(d) {
return color(d.name);
})
.style("fill", "none")
.style("stroke-width", "1px")
.style("opacity", "0");
mousePerLine.append("text")
.attr("transform", "translate(10,3)");
mouseG.append('svg:rect') // append a rect to catch mouse movements on canvas
.attr('width', width) // can't catch mouse events on a g element
.attr('height', height)
.attr('fill', 'none')
.attr('pointer-events', 'all')
.on('mouseout', function() { // on mouse out hide line, circles and text
d3.select(".mouse-line")
.style("opacity", "0");
d3.selectAll(".mouse-per-line circle")
.style("opacity", "0");
d3.selectAll(".mouse-per-line text")
.style("opacity", "0");
})
.on('mouseover', function() { // on mouse in show line, circles and text
d3.select(".mouse-line")
.style("opacity", "1");
d3.selectAll(".mouse-per-line circle")
.style("opacity", "1");
d3.selectAll(".mouse-per-line text")
.style("opacity", "1");
})
.on('mousemove', function() { // mouse moving over canvas
var mouse = d3.mouse(this);
d3.select(".mouse-line")
.attr("d", function() {
var d = "M" + mouse[0] + "," + height;
d += " " + mouse[0] + "," + 0;
return d;
});
d3.selectAll(".mouse-per-line")
.attr("transform", function(d, i) {
console.log(width/mouse[0])
var xDate = x.invert(mouse[0]),
bisect = d3.bisector(function(d) { return d.date; }).right;
idx = bisect(d.values, xDate);
var beginning = 0,
end = lines[i].getTotalLength(),
target = null;
while (true){
target = Math.floor((beginning + end) / 2);
pos = lines[i].getPointAtLength(target);
if ((target === end || target === beginning) && pos.x !== mouse[0]) {
break;
}
if (pos.x > mouse[0]) end = target;
else if (pos.x < mouse[0]) beginning = target;
else break; //position found
}
d3.select(this).select('text')
.text(y.invert(pos.y).toFixed(2));
return "translate(" + mouse[0] + "," + pos.y +")";
});
});
</script>
</body>
</html>
答案 0 :(得分：1)
在mousemove功能中，您已在变量xDate中拥有日期。
因此，您只需要一种新的时间格式：
var parseDate2 = d3.time.format("%Y/%m/%d");
在文本函数中使用xDate：
.text(y.invert(pos.y).toFixed(2) + " - " + parseDate2(xDate));
以下是修改后的代码：
<!DOCTYPE html>
<html>
<head>
<script data-require="d3@3.5.3" data-semver="3.5.3" src="//cdnjs.cloudflare.com/ajax/libs/d3/3.5.3/d3.js"></script>
<style>
body {
font: 10px sans-serif;
}
.axis path,
.axis line {
fill: none;
stroke: #000;
shape-rendering: crispEdges;
}
.x.axis path {
display: none;
}
.line {
fill: none;
stroke: steelblue;
stroke-width: 1.5px;
}
</style>
</head>
<body>
<script>
var myData = "date New York San Francisco Austin\n\
20111001 63.4 62.7 72.2\n\
20111002 58.0 59.9 67.7\n\
20111003 53.3 59.1 69.4\n\
20111004 55.7 58.8 68.0\n\
20111005 64.2 58.7 72.4\n\
20111006 58.8 57.0 77.0\n\
20111007 57.9 56.7 82.3\n\
20111008 61.8 56.8 78.9\n\
20111009 69.3 56.7 68.8\n\
20111010 71.2 60.1 68.7\n\
20111011 68.7 61.1 70.3\n\
20111012 61.8 61.5 75.3\n\
20111013 63.0 64.3 76.6\n\
20111014 66.9 67.1 66.6\n\
20111015 61.7 64.6 68.0\n\
20111016 61.8 61.6 70.6\n\
20111017 62.8 61.1 71.1\n\
20111018 60.8 59.2 70.0\n\
20111019 62.1 58.9 61.6\n\
20111020 65.1 57.2 57.4\n\
20111021 55.6 56.4 64.3\n\
20111022 54.4 60.7 72.4\n";
var margin = {
top: 20,
right: 80,
bottom: 30,
left: 50
},
width = 500 - margin.left - margin.right,
height = 500 - margin.top - margin.bottom;
var parseDate = d3.time.format("%Y%m%d").parse;
var parseDate2 = d3.time.format("%Y/%m/%d");
var x = d3.time.scale()
.range([0, width]);
var y = d3.scale.linear()
.range([height, 0]);
var color = d3.scale.category10();
var xAxis = d3.svg.axis()
.scale(x)
.orient("bottom");
var yAxis = d3.svg.axis()
.scale(y)
.orient("left");
var line = d3.svg.line()
.interpolate("basis")
.x(function(d) {
return x(d.date);
})
.y(function(d) {
return y(d.temperature);
});
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 + ")");
var data = d3.tsv.parse(myData);
color.domain(d3.keys(data[0]).filter(function(key) {
return key !== "date";
}));
data.forEach(function(d) {
d.date = parseDate(d.date);
});
var cities = color.domain().map(function(name) {
return {
name: name,
values: data.map(function(d) {
return {
date: d.date,
temperature: +d[name]
};
})
};
});
x.domain(d3.extent(data, function(d) {
return d.date;
}));
y.domain([
d3.min(cities, function(c) {
return d3.min(c.values, function(v) {
return v.temperature;
});
}),
d3.max(cities, function(c) {
return d3.max(c.values, function(v) {
return v.temperature;
});
})
]);
var legend = svg.selectAll('g')
.data(cities)
.enter()
.append('g')
.attr('class', 'legend');
legend.append('rect')
.attr('x', width - 20)
.attr('y', function(d, i) {
return i * 20;
})
.attr('width', 10)
.attr('height', 10)
.style('fill', function(d) {
return color(d.name);
});
legend.append('text')
.attr('x', width - 8)
.attr('y', function(d, i) {
return (i * 20) + 9;
})
.text(function(d) {
return d.name;
});
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(xAxis);
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("Temperature (ºF)");
var city = svg.selectAll(".city")
.data(cities)
.enter().append("g")
.attr("class", "city");
city.append("path")
.attr("class", "line")
.attr("d", function(d) {
return line(d.values);
})
.style("stroke", function(d) {
return color(d.name);
});
city.append("text")
.datum(function(d) {
return {
name: d.name,
value: d.values[d.values.length - 1]
};
})
.attr("transform", function(d) {
return "translate(" + x(d.value.date) + "," + y(d.value.temperature) + ")";
})
.attr("x", 3)
.attr("dy", ".35em")
.text(function(d) {
return d.name;
});
var mouseG = svg.append("g")
.attr("class", "mouse-over-effects");
mouseG.append("path") // this is the black vertical line to follow mouse
.attr("class", "mouse-line")
.style("stroke", "black")
.style("stroke-width", "1px")
.style("opacity", "0");
var lines = document.getElementsByClassName('line');
var mousePerLine = mouseG.selectAll('.mouse-per-line')
.data(cities)
.enter()
.append("g")
.attr("class", "mouse-per-line");
mousePerLine.append("circle")
.attr("r", 7)
.style("stroke", function(d) {
return color(d.name);
})
.style("fill", "none")
.style("stroke-width", "1px")
.style("opacity", "0");
mousePerLine.append("text")
.attr("transform", "translate(10,3)");
mouseG.append('svg:rect') // append a rect to catch mouse movements on canvas
.attr('width', width) // can't catch mouse events on a g element
.attr('height', height)
.attr('fill', 'none')
.attr('pointer-events', 'all')
.on('mouseout', function() { // on mouse out hide line, circles and text
d3.select(".mouse-line")
.style("opacity", "0");
d3.selectAll(".mouse-per-line circle")
.style("opacity", "0");
d3.selectAll(".mouse-per-line text")
.style("opacity", "0");
})
.on('mouseover', function() { // on mouse in show line, circles and text
d3.select(".mouse-line")
.style("opacity", "1");
d3.selectAll(".mouse-per-line circle")
.style("opacity", "1");
d3.selectAll(".mouse-per-line text")
.style("opacity", "1");
})
.on('mousemove', function() { // mouse moving over canvas
var mouse = d3.mouse(this);
d3.select(".mouse-line")
.attr("d", function() {
var d = "M" + mouse[0] + "," + height;
d += " " + mouse[0] + "," + 0;
return d;
});
d3.selectAll(".mouse-per-line")
.attr("transform", function(d, i) {
var xDate = x.invert(mouse[0]),
bisect = d3.bisector(function(d) { return d.date; }).right;
idx = bisect(d.values, xDate);
var beginning = 0,
end = lines[i].getTotalLength(),
target = null;
while (true){
target = Math.floor((beginning + end) / 2);
pos = lines[i].getPointAtLength(target);
if ((target === end || target === beginning) && pos.x !== mouse[0]) {
break;
}
if (pos.x > mouse[0]) end = target;
else if (pos.x < mouse[0]) beginning = target;
else break; //position found
}
d3.select(this).select('text')
.text(y.invert(pos.y).toFixed(2) + " - "
+ parseDate2(xDate));
return "translate(" + mouse[0] + "," + pos.y +")";
});
});
</script>
</body>
</html>