4
我正在尝试使用D3.js绘制动态堆积的条形图。基本要求是我将每隔几秒钟获得一个新的数据点，并且我应该能够重新绘制（转换）堆叠图表。这是我写的代码：D3中的动态堆积条形图
<html>
<head>
<title>Page Title</title>
<script type="text/javascript" src="http://code.jquery.com/jquery-latest.min.js"></script>
<script src="d3/d3.js"></script>
<script src="d3/d3.csv.js"></script>
<script src="d3/d3.layout.js"></script>
</head>
<body>
<style type="text/css">
.chart rect {
stroke: white;
}
</style>
<script>
var t = 1297110663, // start time (seconds since epoch)
v = 70, // start value (subscribers)
sentidata = d3.range(33).map(next); // starting dataset
var w = 20,
h = 80;
var x = d3.scale.linear()
.domain([0, 1])
.range([0, w]);
var y = d3.scale.linear()
.domain([0, 200])
.rangeRound([0, h]);
var z = d3.scale.ordinal()
.range(["lightpink", "darkgray"]);
//This function creates random test data of format : time, posvalue, negvalue
function next() {
return {
time: ++t,
posvalue: v = ~~Math.max(10, Math.min(90, v + 10 * (Math.random() - .5))),
negvalue: v = ~~Math.max(10, Math.min(90, v + 10 * (Math.random() - .5)))
};
}
//This function readjusts the data with one new data point and calls redraw function to replot the graph
setInterval(function() {
sentidata.shift();
sentidata.push(next());
redraw(sentidata);
}, 1500);
var svg = d3.select("body").append("svg:svg")
.attr("class", "chart")
.attr("width", w * sentidata.length - 1)
.attr("height", h);
//Transpose the data into layers by Sentiment
var sent = d3.layout.stack()(["posvalue","negvalue"].map(function(sentiment){
return sentidata.map(function(d){
return {x:d.time, y:+d[sentiment]};
});
}));
//Add a group for each Sentiment
var sentiment = svg.selectAll("g.sentiment")
.data(sent)
.enter()
.append("svg:g")
.attr("class","sentiment")
.style("fill", function(d,i){return z(i);})
.style("stroke", function(d,i){return d3.rgb(z(i)).darker();});
//Add a rectangle for each time value
var rect = sentiment.selectAll("rect")
.data(Object)
.enter()
.append("svg:rect")
.attr("x",function(d, i) { return x(i) - .5; })
.attr("y",function(d){return h - y(d.y0)-y(d.y);})
.attr("height", function(d){return y(d.y);})
.attr("width",w);
svg.append("line")
.attr("x1", 0)
.attr("x2", w * sentidata.length)
.attr("y1", h - .5)
.attr("y2", h - .5)
.style("stroke", "#000");
function redraw(data) {
//Transpose the data into layers by Sentiment
var sent = d3.layout.stack()(["posvalue","negvalue"].map(function(sentiment){
return data.map(function(d){
return {x:d.time, y:+d[sentiment]};
});
}));
//Add a group for each Sentiment
var sentiment = svg.selectAll("g.sentiment")
.data(sent)
.transition()
.duration(1000)
.attr("class","sentiment")
.style("fill", function(d,i){return z(i);})
.style("stroke", function(d,i){return d3.rgb(z(i)).darker();});
var rect = sentiment.selectAll("rect")
.data(Object)
.transition()
.duration(1000)
.attr("y",function(d){return h - y(d.y0)-y(d.y);})
.attr("height", function(d){return y(d.y);});
}
</script>
</body>
</html>
初始堆叠图表得到很好的绘图。但是当我调用重绘方法时，它给了我“[对象对象]没有方法'数据'”错误。这个错误是未来，当我尝试初始化变量RECT
var rect = sentiment.selectAll("rect")
.data(Object)
不知道我做错了。我在找东西similar
任何建议将非常感谢！
'。数据（）'取值或对象数组要用于图。不要传递“对象”，而是传递要显示的数据。 – 2012-03-14 08:53:51
明白了。由于 我使用方法链来在 调用selectAll之后立即创建转换，因此我已将'var sentiment'定义为我重绘中的转换。因此它没有数据方法，因为暗示了错误 消息。因此，我将该转换创建为单独的声明 以避免冲突。感谢Mike Bostoc在D3 Google Groups上快速响应。 – 2012-03-14 17:33:39