在socket.on中绘制一个d3实时线图(socket io) [英] Drawing a d3 realtime line chart inside socket.on (socket io)
问题描述
我使用通过套接字io从服务器接收到的值,并且我想创建一个图表,在新值到达时实时更新。
绘制图表我使用的示例代码: http://jsfiddle.net/chrisJamesC/YruDh/
我收到以下形式的数据:
socket.on('news',function数据){/ *我在这里的图表* / ...});
我替换了 code> next()
函数由我自己的值,也就是我从套接字收到的值,一切都很好。
唯一的问题是,每当一个新的数据点到达时,每两秒钟,不仅图形被更新,但我得到一个完全相同的图表的副本浏览器,下面已经存在的图。这种情况每当我收到一个新的数据点,直到最终我有20个或更多的图表在我的浏览器,导致它崩溃在某一时刻。
我试图在 socket.on
之外创建图表,即使使用与上述示例完全相同的随机数据,也不会显示任何内容。所以我假设我需要创建图形,并在socket.on()方法中每两秒更新一次。
如何创建和更新图表而不制作多个副本?
这是我现在的完整代码:
socket.on('news',function(data){
var o = JSON.parse(data);
awesome = o;
note3.push(awesome.valuee);
var t = -1
var n = 40,
duration = 750
data = d3.range(n).map(next);
function next(){
return {time:++ t,value:awesome.valuee}
}
var margin = {
top:6,
right:0,
bottom:20,
left:40
} ,
width = 560 - margin.right,
height = 120 - margin.top - margin.bottom;
var x = d3.scale.linear()
.domain([t-n + 1,t])
.range([0,width]);
var y = d3.time.scale()
.range([height,0])
.domain([0,400]);;
var line = d3.svg.line()
.interpolate基础)
.x(function(d,i){return x(d.value);})
。 );
var svg = d3.select(body)append(p)append(svg)
.attr(width,width + margin.left + margin.right)
.attr(height,height + margin.top + margin.bottom)
.style(margin-left,-margin.left +px)
.append(g)
.attr(transform,translate(+ margin.left +,+ margin.top +));
svg.append(defs)。append(clipPath)
.attr(id,clip)
.append b $ b .attr(width,width)
.attr(height,height);
var xAxis = d3.svg.axis()。scale(x).orient(bottom);
var axis = svg.append(g)
.attr(class,x axis)
.attr(transform,translate +))
.call(x.axis = xAxis); * /
var path = svg.append(g)
.attr(clip-path,url(#clip))
.append路径)
.data([data])
.attr(class,line);
tick();
function tick(){
//更新域
x.domain([t - n + 2,t]);
//将累计计数推到后面,并重置计数
data.push(next());
//重绘行
svg.select(。line)
.attr(d,line)
.attr空值);
//向左滑动x轴
axis.transition()
.duration(duration)
.ease(linear)
。 call(x.axis);
//向左滑动一行
path.transition()
.duration(duration)
.ease(linear)
.attr transform,translate(+ x(tn)+))
。
//从前面弹出旧数据点
data.shift();
}
});非常感谢你。 解决方案完全未经测试的代码,但您需要重构为这样:
var t = -1,
n = 40,
duration = 750,
data = [];
var margin = {
top:6,
right:0,
bottom:20,
left:40
},
width = 560 - margin.right,
height = 120 - margin.top - margin.bottom;
var x = d3.scale.linear()
.domain([t - n + 1,t])
.range([0,width]);
var y = d3.time.scale()
.range([height,0])
.domain([0,400]);;
var line = d3.svg.line()
.interpolate(basis)
.x(function(d,i){
return x d.time);
})
.y(function(d,i){
return y(d.value);
}
var svg = d3.select(body)append(p)append(svg)
.attr(width,width + margin.left + margin.right)
.attr(height,height + margin.top + margin.bottom)
.style(margin-left,-margin.left +px)
.append(g)
.attr(transform,translate(+ margin.left +,+ margin.top +));
svg.append(defs)。append(clipPath)
.attr(id,clip)
.append b $ b .attr(width,width)
.attr(height,height);
var xAxis = d3.svg.axis()。scale(x).orient(bottom);
var axis = svg.append(g)
.attr(class,x axis)
.attr(transform,translate +))
.call(x.axis = xAxis); * /
var path = svg.append(g)
.attr(clip-path,url(#clip))
.append路径)
.data([data])
.attr(class,line);
function tick(){
//更新域
x.domain([t - n + 2,t]);
//重绘行
svg.select(。line)
.attr(d,line)
.attr空值);
//向左滑动x轴
axis.transition()
.duration(duration)
.ease(linear)
。 call(x.axis);
//向左滑动一行
path.transition()
.duration(duration)
.ease(linear)
.attr transform,translate(+ x(t-n)+));
//从前面弹出旧数据点
if(data.length> 40)data.shift();
}
socket.on('news',function(p){
p = JSON.parse(p);
data.push({
time:++ t,
value:p.valuee
})
tick();
});
I am using values that I receive from a server via socket io, and I want to make a chart that updates in realtime, as new values arrive.
For drawing the graph I am using the code from this example: http://jsfiddle.net/chrisJamesC/YruDh/
And I receive the data in the form below:
socket.on('news', function (data) { /*I make the chart here*/...});
I replaced the value
field in the next()
function by my own values, that is, the values I receive from the socket , and everything works great.
The only problem is that, everytime a new data point arrives, every two seconds, not only the graph gets updated, but I get an exact copy of the same chart in the browser, below the already existing graph. This continues to happen everytime I receive a new data point, until eventually I have 20 or more charts in my browser, causing it to crash at some point.
I tried to create the chart outside of socket.on
, even using random data exactly as it is in the example above, and it doesn't show anything. So I assume that I need to create the graph and update it every two seconds in the socket.on() method.
How can I create and update the chart without making multiple copies of it?
Here is the full code I have now:
socket.on('news', function (data) {
var o= JSON.parse(data);
awesome=o;
note3.push(awesome.valuee);
var t = -1
var n = 40,
duration = 750
data = d3.range(n).map(next);
function next(){
return {time: ++t, value: awesome.valuee }
}
var margin = {
top: 6,
right: 0,
bottom: 20,
left: 40
},
width = 560 - margin.right,
height = 120 - margin.top - margin.bottom;
var x = d3.scale.linear()
.domain([t-n+1, t])
.range([0, width]);
var y = d3.time.scale()
.range([height, 0])
.domain([0, 400]);;
var line = d3.svg.line()
.interpolate("basis")
.x(function (d, i) {return x(d.time);})
.y(function (d, i) {return y(d.value);});
var svg = d3.select("body").append("p").append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.style("margin-left", -margin.left + "px")
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
svg.append("defs").append("clipPath")
.attr("id", "clip")
.append("rect")
.attr("width", width)
.attr("height", height);
var xAxis = d3.svg.axis().scale(x).orient("bottom");
var axis = svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(x.axis=xAxis); */
var path = svg.append("g")
.attr("clip-path", "url(#clip)")
.append("path")
.data([data])
.attr("class", "line");
tick();
function tick() {
// update the domains
x.domain([t - n + 2 , t]);
// push the accumulated count onto the back, and reset the count
data.push(next());
// redraw the line
svg.select(".line")
.attr("d", line)
.attr("transform", null);
// slide the x-axis left
axis.transition()
.duration(duration)
.ease("linear")
.call(x.axis);
// slide the line left
path.transition()
.duration(duration)
.ease("linear")
.attr("transform", "translate(" + x(t-n) + ")")
.each("end", tick);
// pop the old data point off the front
data.shift();
}
});
Thank you so much.
解决方案 Completely untested code, but you need to restructure to something like this:
var t = -1,
n = 40,
duration = 750,
data = [];
var margin = {
top: 6,
right: 0,
bottom: 20,
left: 40
},
width = 560 - margin.right,
height = 120 - margin.top - margin.bottom;
var x = d3.scale.linear()
.domain([t - n + 1, t])
.range([0, width]);
var y = d3.time.scale()
.range([height, 0])
.domain([0, 400]);;
var line = d3.svg.line()
.interpolate("basis")
.x(function(d, i) {
return x(d.time);
})
.y(function(d, i) {
return y(d.value);
});
var svg = d3.select("body").append("p").append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + margin.top + margin.bottom)
.style("margin-left", -margin.left + "px")
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
svg.append("defs").append("clipPath")
.attr("id", "clip")
.append("rect")
.attr("width", width)
.attr("height", height);
var xAxis = d3.svg.axis().scale(x).orient("bottom");
var axis = svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(x.axis = xAxis); * /
var path = svg.append("g")
.attr("clip-path", "url(#clip)")
.append("path")
.data([data])
.attr("class", "line");
function tick() {
// update the domains
x.domain([t - n + 2, t]);
// redraw the line
svg.select(".line")
.attr("d", line)
.attr("transform", null);
// slide the x-axis left
axis.transition()
.duration(duration)
.ease("linear")
.call(x.axis);
// slide the line left
path.transition()
.duration(duration)
.ease("linear")
.attr("transform", "translate(" + x(t - n) + ")");
// pop the old data point off the front
if (data.length > 40) data.shift();
}
socket.on('news', function(p) {
p = JSON.parse(p);
data.push({
time: ++t,
value: p.valuee
})
tick();
});
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