Unable to display legend for a quantile scale in D3 - javascript

I am trying to display a legend for a heat map I have created, but am unable to do that. Here is my HTML
<html>
<head>
<title>Heat Map Data Visualization</title>
</head>
<body>
<div class='chart-area'>
<svg class='chart'></svg>
<svg class='legend'></svg>
</div>
</body>
</html>
Here is the code for the legend I am trying to create
var legend = d3.select('.legend')
.data([0].concat(colorScale.quantiles()), function(d){
return d;
});
legend.enter()
.append('g')
.attr('class', 'legend-element');
legend.append("rect")
.attr("x", function(d, i) {
console.log(i);
return legendElementWidth * i + (width - legendElementWidth * buckets);
})
.attr("y", height)
.attr("width", legendElementWidth)
.attr("height", gridHeight / 2)
.style("fill", function(d, i) {
return colors[i];
});
When I use Chrome Developer Tools to inspect the element, I see that the required g elements have been created but they all have dimensions of 0x0.
I read somewhere that rect elements can only be appended to an svg element, which is why I changed my HTML code to include an svg element with a class of legend, however I am still not getting any result.
Here is a link to the codepen for this program
http://codepen.io/redixhumayun/pen/eBqamb?editors=0010

I have modified your pen like this:
// Save the legend svg in a variable
// also changed the translate in order to keep the legend within the svg
// and place it on the right side just for the example's sake
var legendSvg = svg.append('g')
.attr('class', 'legend')
.attr("transform","translate("+ (width - 40) + ",20)")
// Define the legend as you did
var legend = d3.legendColor()
.useClass(true)
.shape('rect')
.orient('vertical')
.title('Temperature Variance')
.shapeWidth(legendElementWidth)
.scale(colorScale);
// And then call legend on the legendSvg not on svg itself
legendSvg.call(legend);
Hope this helps, good luck!

Related

Making more space for a graph legend in d3js

The names of the legend don't fully show.They are cut off, if I increase the width, the bars just grow bigger. How can I accommodate more space for my legend?
I tried appending the legend to the 'svg' tag instead of the 'g' tag but still not the desired results. I even plotted the axis, bars and legend on the 'svg' tag but its still not working.
javascript
const g= svg.append('g')
.attr("transform", `translate(${margin.left},${margin.top})`)
const xAxis= g.append('g')
.call(d3.axisBottom(x).tickSizeOuter(0))
.attr("transform", "translate(0," + innerHeight + ")")
const yAxis= g.append('g')
.call(d3.axisLeft(y).tickSizeOuter(0))
//stack the data? --> stack per subgroup
var stackedData = d3.stack()
.keys(subgroups)
(data)
var legend = g.append('g')
.attr('class', 'legend')
.attr('transform', `translate(${210},${20})`);
legend.selectAll('rect')
.data(subgroups)
.enter()
.append('rect')
.attr('x', 0)
.attr('y', function(d, i){
return i * 20;})
.attr('width', 14)
.attr('height', 14)
.attr('fill', function(d, i){
return color(i);
});
legend.selectAll('text')
.data(subgroups)
.enter()
.append('text')
.text(function(d){
return d;
})
.attr('x',18)
.attr('y', function(d, i){
return i * 18;
})
.attr('text-anchor', 'start')
.attr('alignment-baseline', 'hanging');
//below is my plotted data
telescope,allocated,unallocated
IRSF,61,28
1.9-m,89,0
1.0-m,64,23
// width=300 and heigh=300 for svg
I want to show the full names of the legends just next to the right of the bars for the graph.
Link to the graph is here.
How do I solve the problem?
Your issue is that the SVG's width is too narrow to accomodate showing all of the legend texts.
If your graph follows D3 conventions, space for elements that are auxilliary to graph itself (axis names, ticks, legends, etc.) is made using an margin object. Although I can't see how your graph is made, it looks like yours is setup to use a margin object as well. Following D3 conventions the margin values are fixed, which would explain why changing the width value just makes the bars wider yet still doesn't make space for the legend texts.
Therefore, locate the margin object and change its right value to something higher. Inspecting your example, it looks like doubling it should do it.
Hope this helps!

Redrawing a key on top of a D3 projection after transition

I'm working with a D3 map projection similar to Mike Bostock's Choropleth seen here.
The issue I'm having is that I've added a transition; and when I transition the projection, the map key (seen in the top right corner) is being covered by the background color of the map.
I know I probably just need to redraw the g layer after the transition, but I'm not able to get that working as expected.
I'm originally drawing the key on the map with the following code:
var g = svg.append("g")
.attr("class", "key")
.attr("transform", "translate(0,40)");
g.selectAll("rect")
.data(color.range().map(function(d) {
d = color.invertExtent(d);
if (d[0] == null) d[0] = x.domain()[0];
if (d[1] == null) d[1] = x.domain()[1];
return d;
}))
.enter().append("rect")
.attr("height", 8)
.attr("x", function(d, i) { return 350 + (i * 30)})
.attr("width", 30)
.attr("fill", function(d) { console.log(d[1]); return color(d[1]); });
g.append("text")
.attr("class", "caption")
.attr("x", x.range()[0])
.attr("y", -6)
.attr("fill", "#000")
.attr("text-anchor", "start")
.attr("font-weight", "bold")
.text("Number of Licensed Establishments");
g.call(d3.axisBottom(x)
.tickSize(13)
.tickValues(color.domain()))
.select(".domain")
.remove();
Then I'm transitioning the projection with this code (which also works fine).
path = d3.geoPath(projection);
svg.selectAll("path").transition().duration(2000).attr("d", path);
But the key gets covered. I've tried redrawing it like this:
g.selectAll("g").attr("transform", "translate(0,40)");
It doesn't do anything though. What step am I missing to correctly redraw that g layer on top?
Transitioning a path shouldn't change where it appears in the DOM. Transitioning element attributes with d3 modifies that element in place in the DOM. The following example should demonstrate this (path is appended first and should be behind the text, the path then transitions its d attribute through two d3 symbol paths remaining behind the text):
var svg = d3.select('body').append('svg').attr('width',400).attr('height',200);
var cross = "M-21.213203435596427,-7.0710678118654755L-7.0710678118654755,-7.0710678118654755L-7.0710678118654755,-21.213203435596427L7.0710678118654755,-21.213203435596427L7.0710678118654755,-7.0710678118654755L21.213203435596427,-7.0710678118654755L21.213203435596427,7.0710678118654755L7.0710678118654755,7.0710678118654755L7.0710678118654755,21.213203435596427L-7.0710678118654755,21.213203435596427L-7.0710678118654755,7.0710678118654755L-21.213203435596427,7.0710678118654755Z";
var star = "M0,-29.846492114305246L6.700954981042517,-9.223073285798176L28.38570081386192,-9.223073285798177L10.8423729164097,3.5229005144437298L17.543327897452222,24.146319342950797L1.7763568394002505e-15,11.400345542708891L-17.543327897452215,24.1463193429508L-10.842372916409698,3.522900514443731L-28.38570081386192,-9.22307328579817L-6.7009549810425195,-9.223073285798176Z";
var wye = "M8.533600336205877,4.926876451265144L8.533600336205877,21.9940771236769L-8.533600336205877,21.9940771236769L-8.533600336205877,4.9268764512651435L-23.31422969000131,-3.6067238849407337L-14.78062935379543,-18.387353238736164L0,-9.853752902530289L14.78062935379543,-18.387353238736164L23.31422969000131,-3.6067238849407337Z"
var symbol = svg.append('path')
.attr('transform','translate(100,100)')
.attr('d', cross )
.attr("fill","orange");
var text = svg.append('text')
.attr('x', 100)
.attr('y', 105)
.style('text-anchor','middle')
.text('THIS IS SOME TEXT')
symbol.transition()
.delay(2000)
.attr('d', star )
.duration(2000)
.transition()
.attr('d', wye )
.duration(2000);
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/4.10.0/d3.min.js"></script>
Given your example, it is likely that the key is initially rendered behind the features of the map - only there is no overlap between the two. Each appears as intended. When transitioning, with say a zoom, the features overlap and the key is hidden. As noted in the comments, try g.raise() or d3.select(".key").raise() to move the key to the bottom of the parent container, effectively lifting it above other svg elements (as elements are rendered in the order they appear in the DOM, as close as we get to a z-index in svg). You should only need to apply .raise() once - as the transition won't change the ordering, or alternatively, ensure that the key is appended to the svg last.

Nest multiple rects inside multiple svg containers with d3?

I am trying to nest an individual rect inside each svg element created in the g element, but I can't seem to get it to work.
Here is my code + Plnk;
Plunker
var bar = g.selectAll(".barContainer")
.data(thisData.labels)
.enter()
bar
.append("svg")
.attr("class", "barContainer")
bar
.insert('rect')
.attr('width', function(d) {
console.log(d)
return d.value
})
.attr('height', 20)
.attr('x', 0)
.attr('y', 0)
Currently the DOM is displaying the rect and container class on the same level, where as I would like to nest the rect inside each container.
I've tried a few things but can't seem to crack it, I was hoping someone could point me in the right direction?
Thanks
You have a 'g' element which you append the svg to and then you also append the rect to the 'g'. You want to append the rect to the svg element you create. Something like this :
var bar = g.selectAll(".barContainer")
.data(thisData.labels)
.enter()
var barRectSVG = bar
.append("svg")
.attr("class", "barContainer")
barRectSVG
.insert('rect')
.attr('width', function(d) {
console.log(d)
return d.value
})
.attr('height', 20)
.attr('x', 0)
.attr('y', 0)
Updated plnkr : http://plnkr.co/edit/WYbjT7ekjUuopzs0H9Pi?p=preview

d3 rect not showing up

I want to display the legend (caption?) of some data.
For each part of the legend, I append a rect and a p to a parent division.
The problem is that rect are not showing up.
Here is my code:
var groups = {{ groups|safe }};
groups.forEach(function(group, i) {
var div = d3.select("#collapse-legend");
div.append("rect")
.attr("width", 17)
.attr("height", 17)
.style("fill-opacity", 1)
.style("fill", function (d) { return c(i); });
div.append("p").text(group)
});
Now, when I check the content of my web page, I get both rect and p, but rect:
is not showing up
seems to have a width of 0 (showing its area with firefox)
Is there some mistake in my code? Are there better ways to achieve this? I am very new to javascript and d3.js so please be indulgent ^^
Update
So this is what I ended with.
HTML:
<div ...>
<svg id="legend-svg"></svg>
</div>
JavaScript:
// set height of svg
d3.select("#legend-svg").attr("height", 18*(groups.length+1));
// for each group, append rect then text
groups.forEach(function(group, i) {
d3.select("#legend-svg").append("rect")
.attr("y", i*20)
.attr("width", 18)
.attr("height", 18)
.style("fill-opacity", 1)
.style("fill", function (d) { return c(i); });
d3.select("#legend-svg").append("text")
.attr("x", 25)
.attr("y", i*20+15)
.text(group);
});
SVG elements like <rect> cannot be direct children of html <div> elements. You must put them inside an <svg> container element.
SET X + Y values for rect :
.attr("x", 50)
.attr("y", 50)

D3 - Pie Chart & Force Directed Labels

I'm looking to create a pie chart with floating labels using D3. I'm new to D3 and I'm not even sure this is possible? Can you use the labels of one graph in another somehow? If you can, can you point me to an example?
Shorter Explanation:
I want labels from:
http://bl.ocks.org/1691430
...to be on a pie chart.
Here's the code I was running below:
Or in a JSBIN: http://jsbin.com/awilak/1/edit
If I understand his code correctly, this is the section that adds the labels. I don't understand what the labelForce.update does. From there, I don't care about transition, so that line isn't needed. Then the rest is just drawing the circles and adds a link / line? If someone could integrate that would be amazing but if you can help me understand what's going on and what I'm missing I'd be more than grateful.
// Now for the labels
// This is the only function call needed, the rest is just drawing the labels
anchors.call(labelForce.update)
labels = svg.selectAll(".labels")
.data(data, function(d,i) {return i;})
labels.exit()
.attr("class","exit")
.transition()
.delay(0)
.duration(500)
.style("opacity",0)
.remove();
// Draw the labelbox, caption and the link
newLabels = labels.enter().append("g").attr("class","labels")
newLabelBox = newLabels.append("g").attr("class","labelbox")
newLabelBox.append("circle").attr("r",11)
newLabelBox.append("text").attr("class","labeltext").attr("y",6)
newLabels.append("line").attr("class","link")
labelBox = svg.selectAll(".labels").selectAll(".labelbox")
links = svg.selectAll(".link")
labelBox.selectAll("text").text(function(d) { return d.num})
}
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-type" content="text/html; charset=utf-8">
<title>Testing Pie Chart</title>
<script type="text/javascript" src="http://mbostock.github.com/d3/d3.js?2.1.3"></script>
<script type="text/javascript" src="http://mbostock.github.com/d3/d3.geom.js?2.1.3"></script>
<script type="text/javascript" src="http://mbostock.github.com/d3/d3.layout.js?2.1.3"></script>
<style type="text/css">
.slice text {
font-size: 16pt;
font-family: Arial;
}
</style>
</head>
<body>
<button id="button"> Test </button>
<br>
<form id="controls">
<div>
<h2>Y axis</h2>
<ul id="y-axis">
<li><label><input checked="checked" type="radio" name="y-axis" value="Component">Component</label></li>
<li><label><input type="radio" name="y-axis" value="Browser">Browser</label></li>
<li><label><input type="radio" name="y-axis" value="Version">Version</label></li>
</ul>
</div>
</form>
<script type="text/javascript">
// return a list of types which are currently selected
function plottableTypes () {
var types = [].map.call (document.querySelectorAll ("#coaster-types input:checked"), function (checkbox) { return checkbox.value;} );
return types;
}
var w = 600, //width
h = 600, //height
r = 100,
r2 = 200, //radius
axis = getAxis (), //axes
color = d3.scale.category20c(); //builtin range of colors
data = [
{"Browser":"Internet Explorer ","Version":"8.0","Toatl":2000,"Component":"6077447412293130422"},
{"Browser":"Internet Explorer ","Version":"9.0 ","Toatl":1852,"Component":"6077447412293130422"},
{"Browser":"Internet Explorer ","Version":"6.0 ","Toatl":1754,"Component":"6077447412293130422"},
{"Browser":"Firefox ","Version":"16.0 ","Toatl":1020,"Component":"6077447412293130422"},
{"Browser":"Chrome ","Version":"23.0 ","Toatl":972,"Component":"6077447412293130422"},
{"Browser":"Internet Explorer ","Version":"7.0 ","Toatl":700,"Component":"6077447412293130422"},
{"Browser":"Mobile Safari ","Version":"6.0 ","Toatl":632,"Component":"6077447412293130422"},
{"Browser":"BOT ","Version":"BOT ","Toatl":356,"Component":"6077447412293130422"},
{"Browser":"Firefox ","Version":"8.0 ","Toatl":196,"Component":"6077447412293130422"},
{"Browser":"Mobile Safari ","Version":"5.1 ","Toatl":184,"Component":"6077447412293130422"}
];
var vis = d3.select("body")
.append("svg:svg") //create the SVG element inside the <body>
.data([data]) //associate our data with the document
.attr("width", w) //set the width and height of our visualization (these will be attributes of the <svg> tag
.attr("height", h)
.append("svg:g") //make a group to hold our pie chart
.attr("transform", "translate(" + r2 + "," + r2 + ")") //move the center of the pie chart from 0, 0 to radius, radius
var arc = d3.svg.arc() //this will create <path> elements for us using arc data
.outerRadius(r);
var pie = d3.layout.pie() //this will create arc data for us given a list of values
.value(function(d) { return d.Toatl; }); //we must tell it out to access the value of each element in our data array
var arcs = vis.selectAll("g.slice") //this selects all <g> elements with class slice (there aren't any yet)
.data(pie) //associate the generated pie data (an array of arcs, each having startAngle, endAngle and value properties)
.enter() //this will create <g> elements for every "extra" data element that should be associated with a selection. The result is creating a <g> for every object in the data array
.append("svg:g") //create a group to hold each slice (we will have a <path> and a <text> element associated with each slice)
.attr("class", "slice"); //allow us to style things in the slices (like text)
arcs.append("svg:path")
.attr("fill", function(d, i) { return color(i); } ) //set the color for each slice to be chosen from the color function defined above
.attr("d", arc); //this creates the actual SVG path using the associated data (pie) with the arc drawing function
arcs.append("svg:text") //add a label to each slice
.attr("transform", function(d) { //set the label's origin to the center of the arc
//we have to make sure to set these before calling arc.centroid
d.innerRadius = r2;
d.outerRadius = r;
return "translate(" + arc.centroid(d) + ")"; //this gives us a pair of coordinates like [50, 50]
})
.attr("text-anchor", "middle") //center the text on it's origin
.text(function(d, i) {
if(axis.yAxis == "Component"){
return data[i].Component;
}
return data[i].Browser; //get the label from our original data array
});
d3.select('#button').on('click', reColor);
var arcOver = d3.svg.arc()
.outerRadius(r + 30)
.innerRadius(0);
var arc = d3.svg.arc()
.outerRadius(r)
.innerRadius(0);
var arcs = vis.selectAll("g.slice")
.attr("class", "slice")
.on("mouseover", function(d) {
getAxis();
d3.select(this)
.select("path")
.transition()
.duration(500)
.attr("d", arcOver);
d3.select(this).select("text")
.text(function(d, i) {
if(axis.yAxis == "Component"){
return data[i].Component;
}
return data[i].Browser; //get the label from our original data array
});
})
.on("mouseout", function(d) {
getAxis();
d3.select(this)
.select("path")
.transition()
.duration(500)
.attr("d", arc);
d3.select(this)
.select("text")
.text(function(d, i) {
if(axis.yAxis == "Component"){
return data[i].Component;
}
return data[i].Browser; //get the label from our original data array
});
});
function reColor(){
var slices = d3.select('body').selectAll('path');
slices.transition()
.duration(2000)
.attr("fill", function(d, i) { return color(i+2); } );
slices.transition()
.delay(2000)
.duration(2000)
.attr("fill", function(d, i) { return color(i+10); } )
}
function makeData(){
}
// return an object containing the currently selected axis choices
function getAxis () {
var y = document.querySelector("#y-axis input:checked").value;
return {
yAxis: y,
};
}
function update() {
axis = getAxis()
arcs.selectAll("text") //add a label to each slice
.text(function(d, i) {
if(axis.yAxis == "Component"){
return data[i].Component;
}
return data[i].Browser; //get the label from our original data array
});
}
document.getElementById("controls").addEventListener ("click", update, false);
document.getElementById("controls").addEventListener ("keyup", update, false);
</script>
</body>
</html>
As others mentioned in the comments to your introduction-post it's possible to achieve a solution like you described it and it's possible using your code plus parts of the "moving-labels"-example. If I understand you correctly, you want to achieve non-overlapping labels using the force-layout, which is a pretty nice idea that I didn't stumble upon yet.
The code-part you pasted from the example just draws the labels and the lines as you already explained correctly. The next step is to rearrange the labels in a force-like layout around your pie chart.
The part that rearranges the labels (and links) in the example is the following:
function redrawLabels() {
labelBox
.attr("transform",function(d) { return "translate("+d.labelPos.x+" "+d.labelPos.y+")"})
links
.attr("x1",function(d) { return d.anchorPos.x})
.attr("y1",function(d) { return d.anchorPos.y})
.attr("x2",function(d) { return d.labelPos.x})
.attr("y2",function(d) { return d.labelPos.y})
}
// Initialize the label-forces
labelForce = d3.force_labels()
.linkDistance(0.0)
.gravity(0)
.nodes([]).links([])
.charge(-60)
.on("tick",redrawLabels)
The function is the one that changes the positions of the labels and lines. The force is calculated by D3 and started with the d3.force_labels().... As you can see, the function is assigned as an event-handler for the tick-event. In other words: After every step of calculating the force, D3 calls the 'drawer' for every label and updates the positions.
Unfortunately I'm not very familiar with the force_labels() method of D3, but I would assume it works pretty much like the regular force().
An anchor, in your case, is placed somewhere in each pie-piece for each label. The more centered within each pie-piece (NOT the pie itself), the better. Unfortunately you have to calculate this anchor-position somehow (sin and cos stuff) and set the line-ends to this fixed position within redrawLabels().
After you've done this you will see the first result. You may have to play around with gravity, linkDistance etc values of the force to achieve good results. (That's what the silders in the example do.)
See d3 docs for more info: https://github.com/mbostock/d3/wiki/Force-Layout
Then you will maybe stumble upon the problem that the labels are ordered around the pie without overlapping but in some strange order. You could solve this by initially placing the labels in correct order on a larger circle around your pie instead of positioning them randomly around the panel, which is the cause for the problem. This way you will experience way less jitter and misplacements.
The idea also is described in another blocks example: http://bl.ocks.org/mbostock/7881887
In this example, the nodes are initially placed on a virtual circle. The positioning is calculated by the following functions:
x: Math.cos(i / m * 2 * Math.PI) * 200 + width / 2 + Math.random(),
y: Math.sin(i / m * 2 * Math.PI) * 200 + height / 2 + Math.random()
They represent a circle with a radius of 200, place in the center of the drawing-panel. The circle is divided into m equally large pieces. i/m just calculates the 'piece-positions' where i ranges from 0 to m-1.
Hope I could help!
Yes, you can definitely combine force-labels with a pie chart! There is nothing particularly special about the pie chart labels you started with, they're just text elements that can be positioned like anything else using transform or x/y. It looks like you were initially positioning these labels according to the centroids of the arcs they were labelling, but you can just as easily use another criteria (like the output of a force layout).
D3's force layout calculates positions for things based on a set of constraints about what is fixed, what is movable, and which are connected to which. The labelForce.update method from Mike's bl.ocks example is being used to inform the force layout about how many objects need to be positioned, and where the fixed "anchor" points are. It then saves the computed positions for the labels into the diagram's data model, and they are used later on in the redrawLabels function.
You need to create two arcs. One for the pie chart drawing, and one which is large for the labels to sit on.
// first arc used for drawing the pie chart
var arc = d3.svg.arc()
.outerRadius(radius - 10)
.innerRadius(0);
// label attached to first arc
g.append("text")
.attr("transform", function(d) { return "translate(" + arc.centroid(d) + ")"; })
.attr("dy", ".35em")
.style("text-anchor", "middle")
.text(function(d) { return d.data.age; });
// second arc for labels
var arc2 = d3.svg.arc()
.outerRadius(radius + 20)
.innerRadius(radius + 20);
// label attached to second arc
g.append("text")
.attr("transform", function(d) { return "translate(" + arc2.centroid(d) + ")"; })
.attr("dy", ".35em")
.style("text-anchor", "middle")
.text(function(d) { return d.data.age; });

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