I'm making a simple line chart with in-chart labels using d3.js.
When I draw the axes before the labels, the latter do not get added to the svg element, but they do if I draw them first:
In the second chart, the labels are not just hidden. They are not being appended to the DOM at all.
Here's the bl.ock. The only difference between both scripts is that before.js writes labels before axes, while after.js does it afterwards.
Why does this happen?
The problem is this line when adding the labels:
svg.selectAll('text')
If you have drawn the axes at this point. There will be text elements and the selection above will not be empty. Calling .data() on it causes D3 to match data elements to DOM elements in the selection. In this case, everything is matched and therefore the .enter() selection is empty and no new labels are added.
It works if you run this code first because there are no text elements, the selection is empty and no data is matched. To prevent this, you can for example identify the label text elements explicitly with a class:
svg.selectAll('text.label')
.data(dataset)
.enter()
.append('text')
.attr("class", "label")
.text(Math.floor)
.attr('class', 'data-label')
.attr('x', function (d, i) { return x(i); })
.attr('y', function (d, i) { return y(d + 1); });
With this code, it doesn't matter whether you run it before or after adding the axes.
Related
following code adds symbols on multi series line chart.
I want to skip symbols for specific series among all. Can we conditionally skip a single series from being added in multi series line chart?
lineChart.selectAll("g.dot")
.data(d3Data)
.enter().append("g")
.attr("class", "dot")
.style("fill", "red")
.style("stroke", "red")
.selectAll("svg:path")
.data(function(d) { return d.data; })
.enter().append("svg:path")
.attr("transform",function(d){return "translate("+x(d.key)+","+y(d.value)+")";})
.attr("d", d3.svg.symbol().type(d.seriesSymbol).size(22));
If I set value in d.seriesSymbol as blank of any garbage value then d3 by default displays circle. I dont want even this circle to be displayed. I am writing d3.js code in nodejs.
Do we have "none" kind of keyword to skip symbol?
I'm stumped on this one, I need another set of eyes to help me see what I'm missing. I have a bl.ock up here:
http://bl.ocks.org/hepplerj/c419baa3abf7363cd2d5
As you'll see, a few of the rect elements aren't drawing along the x axis correctly. Any pointers on what I'm overlooking? Much appreciated!
There's just a minor issue with your code. First of all, here's a fiddle that's the same as your bl.ock: http://jsfiddle.net/gp2ex7fw/
View source and count the <g class="bar"> elements, and you'll see that there are only seven, whereas you have data for eight grains. millet/sorghum groats is missing altogether. This creates gaps in each bar, resulting in the bar not filling up the entire height.
This is because of the following part of your code:
d3.select("svg").selectAll("g")
.data(stackLayout(stackData))
.enter()
.append("g")
.attr("class", "bar")
When you do selectAll("g"), you're also selecting the first g element (used for transformation) that was attached to your svg element earlier.
The fix is very easy. Just change the above code to:
d3.select("svg").selectAll(".bar")
.data(stackLayout(stackData))
.enter()
.append("g")
.attr("class", "bar")
Now we're only selecting g elements with class="bar" and not missing any data. Here's a working fiddle: http://jsfiddle.net/gp2ex7fw/1/
I have a webpage with an SVG. On some of its shapes I need to display a tooltip. However, I can't get the tooltip to appear where it should, just some pixels away from the shape itself.
It appears way on the right hand side of the screen, maybe some 300px away.
The code I am using to get the coordinates is as follows:
d3.select("body")
.select("svg")
.select("g")
.selectAll("circle")
.on("mouseover", function(){return tooltip.style("visibility", "visible");})
.on("mousemove", function(){
var svgPos = $('svg').offset(),
/*** Tooltip ***/
//This should be the correct one, but is displaying at all working at all.
/*x = svgPos.left + d3.event.target.cx.animVal.value,
y = svgPos.top + d3.event.target.cy.animVal.value;*/
//This displays a tool tip but way much to the left of the screen.
x = svgPos.left + d3.event.target.cx.animVal.value,
y = svgPos.top + d3.event.target.cy.animVal.value;
Tooltip
window.alert("svgPos: "+svgPos+" top: "+y+"px left: "+x+"px "+d3.event.target.cx.animVal.value);
return tooltip.style("top", x+"px").style("left",y+"px");
})
.on("mouseout", function(){return tooltip.style("visibility", "hidden");});
I got to this code following this SO post.
I have changed $(ev.target).attr(cx) as it is not returning a value on my machine; d3.event.target.cx is, even though it seems it is not affecting the end result anyway.
What am I doing wrong? Could somebody help me please? Thank you very much in advance for your time.
If your tooltip is an HTML element, then you want to position it relative to the page as a whole, not the internal SVG coordinates, so accessing the cx/cy value is just complicating things. I can't say for sure without looking at your code, but if you have any transforms on your <svg> or <g> elements, then that could be what's throwing you off.
However, there is a much easier solution. Just access the mouse event's default .pageX and .pageY properties, which give the position of the mouse relative to the HTML body, and use these coordinates to position your tooltip div.
Example here: http://fiddle.jshell.net/tPv46/1/
Key code:
.on("mousemove", function () {
//console.log(d3.event);
return tooltip
.style("top", (d3.event.pageY + 16) + "px")
.style("left", (d3.event.pageX + 16) + "px");
})
Even with rotational transforms on the SVG circles, the mouse knows where it is on the page and the tooltip is positioned accordingly.
There are other ways to do this, including getting a tooltip to show up in a fixed location relative to the circle instead of following the mouse around, but I just checked the examples I was working on and realized they aren't cross-browser compatible, so I'll have to standardize them and get back to you. In the meantime, I hope this gets you back on track with your project.
Edit 1
For comparison, here is the same example implemented with both an HTML tooltip (a <div> element) and an SVG tooltip (a <g> element).
http://fiddle.jshell.net/tPv46/4/
The default mouse event coordinates may be great for positioning HTML elements that are direct children of <body>, but they are less useful for positioning SVG elements. The d3.mouse() function calculates the mouse coordinates of the current event relative to a specified SVG element's coordinate system, after all transformations have been applied. It can therefore be used to get the mouse coordinates in the form we need to position an SVG tooltip.
Key code:
.on("mousemove", function () {
var mouseCoords = d3.mouse(
SVGtooltip[0][0].parentNode);
//the d3.mouse() function calculates the mouse
//position relative to an SVG Element, in that
//element's coordinate system
//(after transform or viewBox attributes).
//Because we're using the coordinates to position
//the SVG tooltip, we want the coordinates to be
//with respect to that element's parent.
//SVGtooltip[0][0] accesses the (first and only)
//selected element from the saved d3 selection object.
SVGtooltip
.attr("transform", "translate(" + (mouseCoords[0]-30)
+ "," + (mouseCoords[1]-30) + ")");
HTMLtooltip
.style("top", (d3.event.pageY + 16) + "px")
.style("left", (d3.event.pageX + 16) + "px");
})
Note that it works even though I've scaled the SVG with a viewBox attribute and put the tooltip inside a <g> with a transform attribute.
Tested and works in Chrome, Firefox, and Opera (reasonably recent versions) -- although the text in the SVG tooltip might extend past its rectangle depending on your font settings. One reason to use an HTML tooltip! Another reason is that it doesn't get cut off by the edge of the SVG.
Leave a comment if you have any bugs in Safari or IE9/10/11. (IE8 and under are out of luck, since they don't do SVG).
Edit 2
So what about your original idea, to position the tooltip on the circle itself? There are definite benefits to being able to position the tip exactly: better layout control, and the text doesn't wiggle around with the mouse. And most importantly, you can just position it once, on the mouseover event, instead of reacting to every mousemove event.
But to do this, you can no longer just use the mouse position to figure out where to put the tooltip -- you need to figure out the position of the element, which means you have to deal with transformations. The SVG spec introduces a set of interfaces for locating SVG elements relative to other parts of the DOM.
For converting between two SVG transformation systems you use SVGElement.getTransformToElement(SVGElement); for converting between an SVG coordinate system and the screen, you use SVGElement.getScreenCTM(). The result are transformation matrices from which you can
extract the net horizontal and vertical translation.
The key code for the SVG tooltip is
var tooltipParent = SVGtooltip[0][0].parentNode;
var matrix =
this.getTransformToElement(tooltipParent)
.translate(+this.getAttribute("cx"),
+this.getAttribute("cy"));
SVGtooltip
.attr("transform", "translate(" + (matrix.e)
+ "," + (matrix.f - 30) + ")");
The key code for the HTML tooltip is
var matrix = this.getScreenCTM()
.translate(+this.getAttribute("cx"),
+this.getAttribute("cy"));
absoluteHTMLtooltip
.style("left",
(window.pageXOffset + matrix.e) + "px")
.style("top",
(window.pageYOffset + matrix.f + 30) + "px");
Live example: http://fiddle.jshell.net/tPv46/89/
Again, I'd appreciate a confirmation comment from anyone who can test this in Safari or IE -- or any mobile browser. I'm pretty sure I've used standard API for everything, but just because the API is standard doesn't mean it's universally implemented!
I have been stuck on this problem for days.
So I have a dataset of objects of the following form:
dataset = [{metric:"revenue",value:0.03},{metric:"sales", value:0.15},{metric:"churn", value: 0.06},{metric:"logins", value: 0.45}]
The following code would display the 4 metric names in a grid pattern (meshy, meshx are the coordinates points of the grid and meshsize is the size of the grid, so this is just putting the text in the middle of a grid square):
svg.selectAll("text")
.data(dataset)
.enter()
.append("text")
.text(function(d){
return d.metric;
})
.attr("y",function(d,i){
return meshy[i] + meshsize/2;
})
.attr("x", function(d,i){
return meshx[i] + meshsize/2;
})
.attr("font-size",25)
.attr("font-family","serif")
.attr("text-anchor","middle")
.attr("font-weight","bold");
Now I would like to put the value of the metric right underneath the metric name like so:
svg.append("text")
.data(dataset)
.text(function(d){
return (d.value);
})
.attr("y",function(d,i){
return meshy[i] + meshsize/2 + 20;
})
.attr("x", function(d,i){
return meshx[i] + meshsize/2 ;
})
.attr("font-size",25)
.attr("font-family","serif")
.attr("text-anchor","middle")
.attr("font-weight","bold");
But this only returns the value underneath the metric name for the FIRST metric, the other 3 value texts are not even in the DOM. I have tried multiple approaches including replacing .text with .html as described here:https://github.com/mbostock/d3/wiki/Selections#wiki-html with no success. I have also tried appending paragraph elements instead - this works but the p elements are positioned below the svg body in a list with no obvious way to move them into the right position. The code above is the closest I have come to getting what I need, but for some reason only the first value text shows up. However, I am open to any approach in d3 that gets the job done: 4 metric names with the values right underneath them
In your second block of code, you are only appending one text element, hence only one of them is appearing. What you need to do is to append the text similar to your first block, i.e. with the .enter() selection. For this, you have two choices. You can either save and reuse the .enter() selection, or assign different classes to the two kinds of text to be able to distinguish between them.
Option 1:
var texts = svg.selectAll("text")
.data(dataset)
.enter();
texts.append("text")
.text(function(d){
return d.metric;
})
// set position etc.
texts.append("text")
.text(function(d){
return d.value;
})
// set position etc.
Option 2:
svg.selectAll("text.title")
.data(dataset)
.enter()
.append("text")
.attr("class", "title")
.text(function(d){
return d.metric;
})
// set position etc.
svg.selectAll("text.value")
.data(dataset)
.enter()
.append("text")
.attr("class", "value")
.text(function(d){
return d.value;
})
// set position etc.
The first option is obviously shorter, but depending on what else you want to do, the second option may be preferable -- if you want to modify the text afterwards, it will be a lot easier if you can distinguish between the two kinds of text. You can also use the different classes to give different CSS styles.
So I am new to working with Javascript (especially the D3 library) and I am trying to do something not unlike the following example: http://mbostock.github.com/d3/talk/20111116/iris-splom.html. In my case though each cell is the same thing a 4 x 4 grid with exactly the same scale.
So in my case the top level element is a plate. Each plate has rows and columns at the intersection of a row and column a value (a heatmap if you will). I able to create the proper plate elements; however, the data for ALL plates is present under each element rather than properly nested. I tried to attach an image so you can see that each "plate" is the same, if you look at the underlying document structure it is the same and essentially each rectangle is two overlaid data points.
In looking more closely at Mike's example (link above), it looks like he uses a cross function to help out with the nesting of data, I am wondering if that is where my code falls down. Thank you for any help you all can provide.
I have posted my code below
d3.csv("plateData.csv", function(data) {
var m = 20,
w = 400,
h = 300,
x_extent = d3.extent(data, function(d){return d.Rows}),
y_extent = d3.extent(data, function(d){return d.Columns}),
z_extent = d3.extent(data, function(d){return d.Values});
var x_scale = d3.scale.linear()
.range([m, w-m])
.domain(x_extent)
var y_scale = d3.scale.linear()
.range([h-m,m])
.domain(y_extent)
var ramp=d3.scale.linear()
.domain(z_extent)
.range(["blue","red"]);
// Nest data by Plates
var plates = d3.nest()
.key(function(d) { return d.Plate; })
.entries(data);
// Insert an svg element (with margin) for each plate in our dataset.
var svg = d3.select("body").selectAll("svg")
.data(plates)
.enter().append("svg:svg")
.attr("width", w)
.attr("height", h)
//add grouping and rect
.append("svg:g")
.selectAll('rect')
.data(data)
.enter()
.append('svg:rect')
.attr('x', function(d){return x_scale(d.Rows)})
.attr('y', function(d){return y_scale(d.Columns)})
.attr('width', 10)
.attr('height', 10)
.style('fill', function(d){return ramp(d.Values)});
}
);
AND example Data:
Plate,Rows,Columns,Values
12345,1,1,1158.755
12345,1,2,1097.768
12345,1,3,1097.768
12345,1,4,914.807
12345,2,1,1189.249
12345,2,2,1128.261
12345,2,3,1433.197
12345,2,4,701.352
12345,3,1,914.807
12345,3,2,1433.197
12345,3,3,1189.249
12345,3,4,1402.703
12345,4,1,1158.755
12345,4,2,1067.274
12345,4,3,701.352
12345,4,4,1372.21
56987,1,1,20.755
56987,1,2,97.768
56987,1,3,97.768
56987,1,4,14.807
56987,2,1,89.249
56987,2,2,28.261
56987,2,3,33.197
56987,2,4,15.352
56987,3,1,2000.807
56987,3,2,14.197
56987,3,3,89.249
56987,3,4,402.703
56987,4,1,158.755
56987,4,2,3067.274
56987,4,3,701.352
56987,4,4,182.21
You problem has two sources:
You are inserting one svg element for each nested group, but you don't have defined a position for each element (all the elements are in the body).
You are selecting all the svg elements in the body, and appending one rectangle for each data element, without considering the nested structure.
One solution is to create one svg element inside the body, one group for each plate, define a position for each plate, translate the group to its position (in the svg element) and then create the rectangles for the heatmap.