我创建了一个折线图,该折线图使用基于此示例的新数据进行更新 https://bl.ocks.org/EfratVil/92f894ac0ba265192411e73f633a3e2f/645d58cad06fb8408a85afea3f5dc893d949ebc9
虽然我已经能够更新主线,但我终生无法更新下面的上下文行。下面的示例是创建两行的代码
var brush = d3.brushX()
.extent([
[0, 0],
[width, height2]
])
.on("brush end", brushed);
var zoom = d3.zoom()
.scaleExtent([1, Infinity])
.translateExtent([
[0, 0],
[width, height]
])
.extent([
[0, 0],
[width, height]
])
.on("zoom", zoomed);
line = d3.line()
.defined(function(d) {
return d[trace] != null;
})
.x(function(d) {
return x(d.DATE_PST);
})
.y(function(d) {
return y(+d[trace]);
});
line2 = d3.line()
.x(function(d) {
return x2(d.DATE_PST);
})
.y(function(d) {
return y2(+d[trace]);
});
var clip = svg.append("defs").append("svg:clipPath")
.attr("id", "clip")
.append("svg:rect")
.attr("width", width)
.attr("height", height)
.attr("x", 0)
.attr("y", 0);
var Line_chart = svg.append("g")
.attr("class", "focus")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")")
.attr("clip-path", "url(#clip)");
var focus = svg.append("g")
.attr("class", "focus")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
var context = svg.append("g")
.attr("class", "context")
.attr("transform", "translate(" + margin2.left + "," + margin2.top + ")");
x.domain(d3.extent(data, d => d.DATE_PST));
y.domain([d3.min(data, d => +d[trace]), d3.max(data, d => +d[trace])]);
x2.domain(x.domain());
y2.domain(y.domain());
focus.append("g")
.attr("class", "axis axis--x")
.attr("transform", "translate(0," + height + ")")
.call(xAxis);
yaxe = focus.append("g")
.attr("class", "axis axis--y")
.call(yAxis);
Line_chart.append("path")
.datum(data)
.attr("class", "line")
.attr("d", line)
.style("stroke", function() {
if(met.includes(trace)){
c = 'red'
}else{
c = 'steelblue'
}
return c });
context.append("path")
.datum(data)
.attr("class", "line2")
.attr("id", "line2")
.attr("d", line2)
.style("stroke", function() {
if(met.includes(trace)){
c = 'red'
}else{
c = 'steelblue'
}
return c });;
context.append("g")
.attr("class", "axis axis--x")
.attr("transform", "translate(0," + height2 + ")")
.call(xAxis2);
context.append("g")
.attr("class", "brush")
.call(brush)
.call(brush.move, x.range());
focus1 = focus.append("g")
.attr("class", "focus1")
.style("display", "none");
// .attr("transform", "translate(" + margin.left + "," + margin.top + ")")
// .attr("transform", "translate(0," + height + ")");
focus1.append("circle")
.attr("r", 3);
focus1.append("text")
.attr("x", 9)
.attr("dy", ".35em");
svg.append("rect")
.attr("class", "zoom")
.attr("id", "overlay")
.attr("width", width)
.attr("height", height)
.attr("transform", "translate(" + margin.left + "," + margin.top + ")")
.call(zoom)
.on("mouseover", function() {
focus1.style("display", null);
})
.on("mouseout", function() {
focus1.style("display", "none");
})
.on("mousemove", mousemove);
并使用新数据更新 Line_chart:
Line_chart = d3.select("g").transition();
Line_chart.select(".line")
.duration(750)
.attr("d", line)
.style("stroke", function(d) {
if(met.includes(trace)){
c = 'red'
}else{
c = 'steelblue'
}
return c });;
我尝试了很多变体来更新上下文行,但没有成功:
context = d3.select("g").transition();
context.select(".line2")
.duration(750)
.attr("d", line2)
.style("stroke", function(d) {
console.log(d)
if(met.includes(trace)){
c = 'red'
}else{
c = 'steelblue'
}
return c });
如何更新上下文行?
最佳答案
根据提供的代码,您的错误在这里:
context = d3.select("g").transition();
更新主要区域(焦点)时您使用:
Line_chart = d3.select("g").transition();
但是,在更新上下文时(下半部分),您使用相同的选择:
context = d3.select("g").transition();
d3.select
将遍历 DOM,直到找到与选择器匹配的元素。它将为这些语句中的每一个选择相同的 g,因为 d3.select
只选择一个匹配的 DOM 元素,即它遇到的第一个元素。您拥有的第一个 g
是 Line_Chart
g
。
因为它每次都选择相同的元素,所以您永远不会更新第二个或之后的 g
。此外,您正在搜索第一个 g
以查找具有类 line2
(.select(".line2")) 的行,因为此类仅存在于稍后的 g
,它将始终返回空选择 - 因此不会更新任何内容。一种选择是完全删除对 g
的引用并选择具有唯一标识符的行 - 假设只有一行包含该类:
d3.select(".line2") // or better yet, svg.select() as it is in the svg
.transition()
.duration(750)
.attr("d", line2)
.style("stroke", function(d) {
console.log(d)
if(met.includes(trace)){
c = 'red'
}else{
c = 'steelblue'
}
return c });
如果你真的想保留当前的结构,你可以为上下文g
分配一个id:
var context = svg.append("g")
.attr("id","context")
然后在更新行时选择该 id:
context = d3.select("#context").transition();
context.select(".line2")
关于javascript - 加载新数据时更新上下文行 d3,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/47189616/