I have a simple line graph that checks every 5 seconds for updates & redraws the line/scale if needed. This all works well EXCEPT: the data-point dots.
What am I missing in the redraw to move the dots? The dots are there when the graph is first rendered. But on update, they don't move when the line gets redrawn. So I selected a new data source on update, and the old data-points remained fixed.
Redraw on update
var svgAnimate = d3.select("#animateLine").transition();
svgAnimate.select(".line") // change the line
.duration(750)
.attr("d", valueline(data));
svgAnimate.selectAll(".circle") // change the circle
.duration(750)
.attr("d", valueline(data));
svgAnimate.select(".x.axis") // change the x axis
.duration(750)
.call(xAxis);
svgAnimate.select(".y.axis") // change the y axis
.duration(750)
.call(yAxis);
Initial drawing:
svgAnimate.selectAll("dot")
.data(data)
.enter().append("circle")
.attr("class", "circle")
.attr("r", 5)
.style("fill", function(d) {
if (d.close <= 400) {return "red"}
else { return "black" }
;})
.attr("cx", function(d) { return x(d.date); })
.attr("cy", function(d) { return y(d.close); })
This is what I don't want.
Your problem is that the function valueLine is the function you use to draw the line. Thus, when calling it again with a new data you redraw the line.
For the circles the attribute d has no sense. However, if we consider that the y axis does not change, then you can do something like:
svgAnimate.selectAll(".circle") // change the circle
.data(newData)
.duration(750)
.attr("cx", function(d){return x(d.date)};
If you need to change the y coordinates, then you have to modify the cy attribute of the circle.
My code might not be as rigorous as necessary, please post a jsFiddle if you still have problems.
I had some issues with updating circles in charts too.
Here is a working fiddle and might some people for future searches if they have the same problem:
http://jsfiddle.net/noo8k17n/
The problem is this line:
var svgAnimate = d3.select("#animateLine").transition();
It needs to be removed and then in the update method you can add and remove circles.
Related
I am trying to create a line graph using d3.js, which takes a csv input and converts it to a data array with the keys x1, x2, class. Using that data I create a perceptron decision boundary using weights and the gradient function which updates and transitions after each iteration.
This works nicely.
What I am struggling with is the area under the curve, as I want positive values to be blue and negative to be red. The areas move with the line correctly, but something is wrong with the x values as the width of the area doesn't cover the whole graph. It covers about half, and starts about a quarter of the way in (I can't post an image.)
Here is the code I'm using for all of these elements, but I thin I am misunderstanding the way area uses the x attribute;
lineFunction = d3.svg.line()
.x(function(d) { return widthScale(d.x1); })
.y(function(d) { return heightScale(((-d.x1 * w1) - w0)/w2); })
.interpolate("linear");
var area = d3.svg.area()
.x(function(d) { return widthScale(d.x1); })
.y0(xPos)
.y1(function(d) { return heightScale(((-d.x1 * w1) - w0)/w2); })
.interpolate("linear");
var area2 = d3.svg.area()
.x(function(d) { return widthScale(d.x1); })
.y0(heightAlter)
.y1(function(d) { return heightScale(((-d.x1 * w1) - w0)/w2); })
.interpolate("linear");
lineGraph = canvas.append("path")
.attr("d", lineFunction(lineData))
.attr("class", "autoLine")
.attr("stroke", "black")
.attr("stroke-width", 1)
.attr("fill", "none")
.attr("clip-path", "url(#clip)");
shadedArea = canvas.append("path")
.data([data])
.attr("d", area)
.attr("class", "area")
.attr("clip-path", "url(#clip)");
shadedAreaPos = canvas.append("path")
.data([data])
.attr("d", area2)
.attr("class", "area2")
.attr("clip-path", "url(#clip)");
Any help would be much appreciated.
I managed to find that the root of the problem was the way in which the data array was ordered. I do not fully understand what is happening behind the scenes, but by simply reordering the array in ascending order on the x1 values, it now works correctly. I hope this helps someone.
I have put together a D3 line chart and added threshold encoding using clip path / clipping. The only problem I am facing is I am not able to add tooltips to this chart. I want a tooltip when I hover anywhere in the chart and the corresponding y axis value on the chart shows up in the tooltip.
I have added threshold encoding using this example by Mike Bostock.
var line = d3.svg.line()
.interpolate("basis")
.x(function(d) { return _config.xScale(d.vtc); })
.y(function(d) { return _config.yScale(d.values); });
svg.append("clipPath")
.attr("id", "clip-above")
.append("rect")
.attr("width", _config.width)
.attr("height", _config.yScale(55));
svg.append("clipPath")
.attr("id", "clip-below")
.append("rect")
.attr("y", _config.yScale(55))
.attr("width", _config.width)
.attr("height", _config.height - _config.yScale(55));
svg.selectAll(".line")
.data(["above", "below"])
.enter().append("path")
.attr("class", function(d) { return "line " + d; })
.attr("clip-path", function(d) { return "url(#clip-" + d + ")"; })
.datum(data)
.attr("d", line);
I didn't know how to go about adding a tooltip for this particular chart as there is clip rectangle over the path and the path is broken down into above and below segment to give the colour effects.
Do we have a unified way to add a tooltip to normal path and this one? If yes I would like to know some sources/links I can look at.
Something like this, but not that complicated (without any indicator on the line, just the tooltip)
My CODEPEN LINK
You can add mouseOver handler for the line and translate back the mouse y position to yAxis value using the .invert function of d3 linear scale. Now, you can dynamically add a tooltip text element and set the position, value to it
Here is the updated Codepen link
NOTE: You still need to increase the capture area of the line. This can be done by adding a transparent stroke to the line.
svg.selectAll(".line")
.data(["above", "below"])
.enter().append("path")
.attr("class", function(d) { return "line " + d; })
.attr("clip-path", function(d) { return "url(#clip-" + d + ")"; })
.datum(data)
.attr("d", line)
.on("mouseover", function() {
var mousePos = d3.mouse(this);
var yAxisValue = _config.yScale.invert(mousePos[1]);
svg.selectAll(".tooltip").data([mousePos])
.enter().append("text")
.classed("tooltip", true)
.attr("x", function(d) { return d[0]})
.attr("y", function(d) { return d[1]})
.text(yAxisValue);
})
.on("mouseout", function() {
svg.selectAll(".tooltip").data([]).exit().remove();
});
I am trying to draw a set of lines and circle points, but I cant figure out how to get the circles to work.
The line function needs an array of points, but for the circle it needs just the x/y of each point.
How do I append a circle (to the same group as the line), for each x/y point?
// Data join
var join = svg.selectAll("g")
.data(lineData)
// Enter
var group = join.enter()
.append("g");
group.append("path")
.attr('stroke', 'blue')
.attr('stroke-width', 2)
.attr('fill', 'none');
group.append('circle')
.attr("r", 10)
.attr('fill', 'blue');
// Update
join.select("path")
.attr('d', line);
join.select("circle")
.attr("cx", function(d) { return x(d.x); })
.attr("cy", function(d) { return y(d.y); });
Full code is here: http://jsfiddle.net/dxxddvL4/1/
The basic pattern you need to use are nested selections -- for each line, there are multiple circles. It's easier to do the lines and circles separately, lines and g elements first:
var join = svg.selectAll("g")
.data(lineData);
// Enter
join.enter()
.append("g")
.append("path")
.attr('stroke', 'blue')
.attr('stroke-width', 2)
.attr('fill', 'none');
// Update
join.select("path")
.attr('d', line);
join.exit().remove();
The code is basically the same as yours, except that the appended g elements aren't saved in a separate selection and the exit selection is handled by removing the elements. Now the circles, along the same lines:
var circles = join.selectAll("circle")
.data(function(d) { return d; });
circles.enter()
.append('circle')
.attr("r", 10)
.attr('fill', 'blue');
circles.attr("cx", function(d) { return x(d.x); })
.attr("cy", function(d) { return y(d.y); });
circles.exit().remove();
The first line here is the nested selection -- for each element in the array that denotes the line, we want a circle. Note that this is operating on the update selection of the g elements. This is ok because the elements in the enter selection are merged into the update selection when the g elements are appended. That is, even though we only handle the update selection, any newly-appended elements are included in this.
After that, we handle the selections as usual. The enter selection has elements appended, the update selection sets the coordinates, the exit selection removes elements. All the magic happens in that first line, where we tell D3 to, for each g element at the top level, bind each point from the line to any circles underneath.
Complete example here.
I am basically trying to clip a chart containing "path" elements representing data points.
It seems like, path elements are not initially "transformed" and remain at (0,0) and are thus clipped by rectangle surrounding entire chart.
Basically, I have replaced "circle" elements as drawn in D3 Brush Example with "path" elements of symbol type "circle".
.append("circle")
.attr("class", "point")
.attr("clip-path", "url(#clip)")
.attr("r", function(d){return Math.floor(Math.random() * (20 - 5 + 1) + 5);})
.attr("cx", function(d) { return x(d.index); })
.attr("cy", function(d) { return y(d.value); })
replaced with
.append("path")
.attr("class", "point")
.attr("clip-path","url(#clip)")
.attr("d", d3.svg.symbol().type("circle"))
Here is jsfiddle. As you can see, only lower right quarter of the circle is visible and rest have been clipped out. What is going on? What is the solution?
Edit:
Also, the actual "clipping" is not working for those circles(paths). Why is that? Why does it work for "circle" but not for "path"?
I've created a little test line chart using D3, but since I am quite new to the library I am not sure what the best way would be to add multiple lines to a chart, at the moment I only have one line displayed in this fiddle.
I would like to display 2 lines on the chart, but I am unsure of how to achieve that without copy pasting code, which I am sure would be very inefficient as I would like to update/animate the graph at regular intervals based on user selection.
Instead of this,
var data = [12345,22345,32345,42345,52345,62345,72345,82345,92345,102345,112345,122345,132345,142345];
I would like to display something like this,
var data = [
[12345,42345,3234,22345,72345,62345,32345,92345,52345,22345], // line one
[1234,4234,3234,2234,7234,6234,3234,9234,5234,2234] // line two
];
Would this be a possibility? If so, what would be the best way to approach this, so that I can easily update/animate the graph when needed?
Note: I am merely trying to learn and to familiarize myself with D3 best practices and the library as a whole. Thanks.
This is possible and reasonable.
There is a tutorial that approaches this at the
D3 Nested Selection Tutorial
which describes nesting of data.
Below is code that I hacked from your fiddle to demonstrate this.
var data = [
[12345,42345,3234,22345,72345,62345,32345,92345,52345,22345],
[1234,4234,3234,2234,7234,6234,3234,9234,5234,2234]
];
var width = 625,
height = 350;
var x = d3.scale.linear()
.domain([0,data[0].length]) // Hack. Computing x-domain from 1st array
.range([0, width]);
var y = d3.scale.linear()
.domain([0,d3.max(data[0])]) // Hack. Computing y-domain from 1st array
.range([height, 0]);
var line = d3.svg.line()
.x(function(d,i) { return x(i); })
.y(function(d) { return y(d); });
var area = d3.svg.area()
.x(line.x())
.y1(line.y())
.y0(y(0));
var svg = d3.select("body").append("svg")
//.datum(data)
.attr("width", width)
.attr("height", height)
//.append("g");
var lines = svg.selectAll( "g" )
.data( data ); // The data here is two arrays
// for each array, create a 'g' line container
var aLineContainer = lines
.enter().append("g");
/*svg.append("path")
.attr("class", "area")
.attr("d", area);*/
aLineContainer.append("path")
.attr("class", "area")
.attr("d", area);
/*svg.append("path")
.attr("class", "line")
.attr("d", line);*/
aLineContainer.append("path")
.attr("class", "line")
.attr("d", line);
/*svg.selectAll(".dot")
.data(data)
.enter().append("circle")
.attr("class", "dot")
.attr("cx", line.x())
.attr("cy", line.y())
.attr("r", 3.5);*/
// Access the nested data, which are values within the array here
aLineContainer.selectAll(".dot")
.data( function( d, i ) { return d; } ) // This is the nested data call
.enter()
.append("circle")
.attr("class", "dot")
.attr("cx", line.x())
.attr("cy", line.y())
.attr("r", 3.5);
One deficiency is that I computed the domain for the x and y axes off the first array, which is a hack, but not pertinent to your question exactly.