SO 社区,
我正在制作一个 D3 直方图作为 Angular 指令,我希望它能够随着它读取的数据发生变化而相应地改变/更新。换句话说,我正在使用 Angular 来观察数据的变化,并(希望)在每次数据发生变化时重新绘制直方图。
这可能主要是关于 D3 的数据更新和绑定(bind)的问题,因为 $watchCollection 似乎工作正常。即使我经历了this tutorial在向 d3 图表添加元素时,我仍然无法将其应用到我的直方图上。我认为直方图中元素的嵌套方式让我很困惑...
上下文:理想情况下,此直方图将从一个数组中读取,从多个 Ajax 调用返回的数据将存储在该数组中。因此,每次新数据集到达时,直方图都会自行增长另一个条形图。这就是为什么我很想知道如何正确更新图表和 x 轴的原因。
谢谢! :)
JS fiddle 在这里:http://jsfiddle.net/santina/wrtenjny/1/
此处仅提供 d3 部分的代码,主要取自 mbostock 的可排序条形图。
// Aesthetic settings
var margin = {top: 20, right: 50, bottom: 20, left: 50},
width = document.getElementById('performance').clientWidth - margin.left - margin.right ||
940 - margin.left - margin.right,
height = 500 - margin.top - margin.bottom,
barColor = "steelblue",
axisColor = "whitesmoke",
axisLabelColor = "grey",
yText = "# QUERIES",
xText = "BEACON IDs";
// Inputs to the d3 graph
var data = scope[attrs.data];
// A formatter for counts.
var formatCount = d3.format(",.0f");
// Set the scale, separate the first bar by a bar width from y-axis
var x = d3.scale.ordinal()
.rangeRoundBands([0, width], .1, 1);
var y = d3.scale.linear()
.range([height, 0]);
var xAxis = d3.svg.axis()
.scale(x)
.orient("bottom");
var yAxis = d3.svg.axis()
.scale(y)
.orient("left")
.tickFormat(formatCount);
// Initialize histogram
var svg = d3.select(".histogram-chart")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
function drawAxis(){
data.forEach(function(d) {
d.nqueries = +d.nqueries;
});
x.domain(data.map(function(d) { return d.name; }));
y.domain([0, d3.max(data, function(d) { return d.nqueries; })]);
// Draw x-axis
svg.append("g")
.attr("class", "x-axis")
.attr("transform", "translate(0," + height + ")")
.call(xAxis)
.append("text")
.attr("y", 6)
.attr("dy", "-0.71em")
.attr("x", width )
.style("text-anchor", "end")
.style("fill", axisLabelColor)
.text(xText);
// Draw y-axis
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")
.style("fill", axisLabelColor)
.text(yText);
// Change axis color
d3.selectAll("path").attr("fill", axisColor);
}
function updateAxis(){
console.log(data);
data.forEach(function(d) {
d.nqueries = +d.nqueries;
});
x.domain(data.map(function(d) { return d.name; }));
y.domain([0, d3.max(data, function(d) { return d.nqueries; })]);
svg.selectAll("g.y_axis").call(yAxis);
svg.selectAll("g.x_axis").call(xAxis);
}
function drawHistogram(){
drawAxis();
var bar = svg.selectAll(".bar")
.data(data)
.enter().append("g")
.attr("class", "barInfo");
bar.append("rect")
.attr("class", "bar")
.attr("x", function(d){ return x(d.name) })
.attr("width", x.rangeBand())
.attr("y", function(d){ return y(d.nqueries) })
.attr("height", function(d) { return height - y(d.nqueries); })
.attr("fill", barColor);
bar.append("text")
.attr("y", function(d){ return y(d.nqueries) })
.attr("x", function(d){ return x(d.name) })
.attr("dy", "-1px")
.attr("dx", x.rangeBand()/2 )
.attr("text-anchor", "middle")
.attr("class", "numberLabel")
.text(function(d) { return formatCount(d.nqueries); });
}
// Doesn't work :(
function updateHistogram(){
console.log("updating");
// Redefine scale and update axis
updateAxis();
// Select
var bar = svg.selectAll(".barInfo").data(data);
// Update - rect
var rects = bar.selectAll("rect")
.attr("class", "bar")
.attr("x", function(d){ return x(d.name) })
.attr("width", x.rangeBand());
// Update
var texts = bar.selectAll("text")
.attr("x", function(d){ return x(d.name) })
.attr("dx", x.rangeBand()/2 );
// Enter
bar.enter().append("g")
.attr("class", "bar").selectAll("rect").append("rect")
.attr("class", "bar")
.attr("x", function(d){ return x(d.name) })
.attr("width", x.rangeBand())
.attr("y", function(d){ return y(d.nqueries) })
.attr("height", function(d) { return height - y(d.nqueries); })
.attr("fill", barColor);
bar.enter().append("g")
.attr("class", "bar").selectAll("text").append("text")
.attr("y", function(d){ return y(d.nqueries) })
.attr("x", function(d){ return x(d.name) })
.attr("dy", "-1px")
.attr("dx", x.rangeBand()/2 )
.attr("text-anchor", "middle")
.attr("class", "numberLabel")
.text(function(d) { return formatCount(d.nqueries); });
}
drawHistogram();
最佳答案
首先,您在更新轴时得到了错误的 class
选择器:
svg.selectAll("g.y-axis").call(yAxis); //<-- dash not underscore
svg.selectAll("g.x-axis").call(xAxis);
其次,您的更新已接近尾声,但我们可以稍微清理一下:
// select on what you originally binded data to
var bar = svg.selectAll(".barInfo").data(data);
// for data entering
var bEnter = bar.enter().append("g")
.attr("class", "barInfo");
// append a rect
bEnter.append("rect")
.attr("class", "bar");
// and the text elements
bEnter.append("text")
.attr("class","numberLabel");
// now we can update everybody together
bar.select("rect")
.attr("x", function(d){ return x(d.name) })
.attr("width", x.rangeBand())
.attr("y", function(d){ return y(d.nqueries) })
.attr("height", function(d) { return height - y(d.nqueries); })
.attr("fill", barColor);
bar.select("text")
.attr("y", function(d){ return y(d.nqueries) })
.attr("x", function(d){ return x(d.name) })
.attr("dy", "-1px")
.attr("dx", x.rangeBand()/2 )
.attr("text-anchor", "middle")
.attr("class", "numberLabel")
.text(function(d) { return formatCount(d.nqueries); });
更新示例 here .
编辑
糟糕,我没有正确选择我的更新。
bar.selectAll("rect")
应该是:
bar.select("rect")
这修复了更新和排序...
已更新 fiddle .
另请注意,我进一步折叠了您的代码。使用 Angular watch ,您真的不需要单独的绘制和更新功能,两者都可以。
关于angularjs - 数据传入时更新 D3 直方图,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/31628050/