Adding Legend on a basic chart - javascript

I am brand new to d3.js and stackoverflow so please pardon if I ask something very basic. I have a basic donut chart however it is a modification of a normal donut chart since you can see there is one on top of another. I was wondering if it is possible to add a label right on the chart. I am able to add legend and label outside the chart but i want to be able to add a label right on the chart itself.
This is the code for chart
var dataset = {
data1: [53245, 28479, 19697, 24037, 40245],
data2: [53245, 28479, 19697, 24037, 40245]
};
var width = 460,
height = 300,
cwidth = 45;
var color = d3.scale.category20();
var pie = d3.layout.pie()
.sort(null);
var arc = d3.svg.arc();
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height)
.append("g")
.attr("transform", "translate(" + width / 2 + "," + height / 2 + ")");
var gs = svg.selectAll("g").data(d3.values(dataset)).enter().append("g");
var path = gs.selectAll("path")
.data(function(d) { return pie(d); })
.enter().append("path")
.attr("fill", function(d, i) { return color(i); })
.attr("d", function(d, i, j) { return arc.innerRadius(10+cwidth*j).outerRadius(cwidth*(j+1))(d); });
This is the FIDDLE. I would highly be pleased with any suggestions to be able to add label and legend. I would want label to be on top of both the charts in the fiddle.

Is this what you're looking for? Fiddle.
Essentially what this does is append a text element which is positioned using the angle of the path element.
var angle = d.endAngle - d.startAngle;
var loc = d.startAngle - (Math.PI/2) + (angle/2);
return Math.sin(loc) * radius;
If you want the labels on the left side to not overlap onto the chart you could use something similar to the following
var textLength = [];
gEnter.selectAll("text").each(function () {
textLength.push(this.getComputedTextLength());
});
To get the lengths of the text objects, then you can modify either .attr("x", ...) or .attr("transform", "translate(x,0)") when d.startAngle is greater than PI (meaning that it is on the left side of the chart), subtracting the text length from the x element to position it further left.

Related

Show values for half donut pie chart in D3 JS

I'm trying to display labels with its value and tooltip in semi donut pie chart using D3 JS.
I'm not able to display labels and their values at the simultaneously.
And how can I add the tooltip on this chart?
I tried implementing this fiddle.
https://jsfiddle.net/SampathPerOxide/hcvuqjt2/6/
var width = 400;
var height = 300; //this is the double because are showing just the half of the pie
var radius = Math.min(width, height) / 2;
var labelr = radius + 30; // radius for label anchor
//array of colors for the pie (in the same order as the dataset)
var color = d3.scale
.ordinal()
.range(['#2b5eac', '#0dadd3', '#ffea61', '#ff917e', '#ff3e41']);
data = [
{ label: 'CDU', value: 10 },
{ label: 'SPD', value: 15 },
{ label: 'Die Grünen', value: 8 },
{ label: 'Die Mitte', value: 1 },
{ label: 'Frei Wähler', value: 3 }
];
var vis = d3
.select('#chart')
.append('svg') //create the SVG element inside the <body>
.data([data]) //associate our data with the document
.attr('width', width) //set the width and height of our visualization (these will be attributes of the <svg> tag
.attr('height', height)
.append('svg:g') //make a group to hold our pie chart
.attr('transform', 'translate(' + width / 2 + ',' + height / 2 + ')'); //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
.innerRadius(79)
// .outerRadius(radius);
.outerRadius(radius - 10); // full height semi pie
//.innerRadius(0);
var pie = d3.layout
.pie() //this will create arc data for us given a list of values
.startAngle(-90 * (Math.PI / 180))
.endAngle(90 * (Math.PI / 180))
.padAngle(0.02) // some space between slices
.sort(null) //No! we don't want to order it by size
.value(function(d) {
return d.value;
}); //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')
.attr('class', 'labels') //add a label to each slice
.attr('fill', 'grey')
.attr('transform', function(d) {
var c = arc.centroid(d),
xp = c[0],
yp = c[1],
// pythagorean theorem for hypotenuse
hp = Math.sqrt(xp * xp + yp * yp);
return 'translate(' + (xp / hp) * labelr + ',' + (yp / hp) * labelr + ')';
})
.attr('text-anchor', 'middle') //center the text on it's origin
.text(function(d, i) {
return data[i].value;
})
.text(function(d, i) {
return data[i].label;
}); //get the label from our original data array
I'm trying to achieve this. https://i.imgur.com/kTXeAXt.png
First of all, if you console.log the data (from .data(pie)) you used for displaying text label and value, you will noticed that label can only be access via d.data.label instead of data[i].label.
{data: {label: "Frei Wähler", value: 3}, value: 3, startAngle: 1.304180706233562, endAngle: 1.5707963267948966, padAngle: 0.02}
Therefore in order to correctly display both label and value, the code should be:
arcs.append("svg:text")
.attr("class", "labels")//add a label to each slice
.attr("fill", "grey")
.attr("transform", function(d) {
var c = arc.centroid(d),
xp = c[0],
yp = c[1],
// pythagorean theorem for hypotenuse
hp = Math.sqrt(xp*xp + yp*yp);
return "translate(" + (xp/hp * labelr) + ',' +
(yp/hp * labelr) + ")";
})
.attr("text-anchor", "middle") //center the text on it's origin
.text(function(d, i) { return d.data.value; })
.text(function(d, i) { return d.data.label; });
How to add tooltip
As for how to create d3 tooltip, it needs a little of css, html and then add d3 event handling.
1) add the following html to your index.html:
<div id="tooltip" class="hidden"><p id="tooltip-data"></p></div>
2) add a little bit css to set the div to position:absolute and hide the tooltip with display:none, and gives it a little bit styling per your preference:
<style>
#tooltip {
position:absolute;
background: #ffffe0;
color: black;
width: 180px;
border-radius: 3px;
box-shadow: 2px 2px 6px rgba(40, 40, 40, 0.5);
}
#tooltip.hidden {
display:none;
}
#tooltip p {
margin: 0px;
padding: 8px;
font-size: 12px;
}
3) We then add mouseover event handler, the idea is when the mouse is over the chart, we will set the top and left properties of the #tooltip css style to where the mouse is, and set the css display property to show the tooltip.
//tooltip
arcs.on("mouseover", function(d) {
d3.select("#tooltip")
.style("left", `${d3.event.clientX}px`)
.style("top", `${d3.event.clientY}px`)
.classed("hidden", false);
d3.select("#tooltip-data")
.html(`Label: ${d.data.label}<br>Value: ${d.data.value}`);
});
arcs.on("mouseout", function(d) {
d3.select("#tooltip")
.classed("hidden", true);
});
selection.text([value])
If a value is specified, sets the text content to the specified value on all selected elements, replacing any existing child elements.
So you are setting the text content with the value and immediately replacing it with the label.
What you can do is return a combined string from the value and label of your datum in a template literal like this:
.text(function(d, i) { return `${data[i].value} - ${data[i].label}`; })
var width = 400;
var height = 300; //this is the double because are showing just the half of the pie
var radius = Math.min(width, height) / 2;
var labelr = radius + 30; // radius for label anchor
//array of colors for the pie (in the same order as the dataset)
var color = d3.scale.ordinal()
.range(['#2b5eac', '#0dadd3', '#ffea61', '#ff917e', '#ff3e41']);
data = [{
label: 'CDU',
value: 10
},
{
label: 'SPD',
value: 15
},
{
label: 'Die Grünen',
value: 8
},
{
label: 'Die Mitte',
value: 1
},
{
label: 'Frei Wähler',
value: 3
}
];
var vis = d3.select("#chart")
.append("svg") //create the SVG element inside the <body>
.data([data]) //associate our data with the document
.attr("width", width) //set the width and height of our visualization (these will be attributes of the <svg> tag
.attr("height", height)
.append("svg:g") //make a group to hold our pie chart
.attr('transform', 'translate(' + (width / 2) + ',' + (height / 2) + ')'); //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
.innerRadius(79)
// .outerRadius(radius);
.outerRadius(radius - 10) // full height semi pie
//.innerRadius(0);
var pie = d3.layout.pie() //this will create arc data for us given a list of values
.startAngle(-90 * (Math.PI / 180))
.endAngle(90 * (Math.PI / 180))
.padAngle(.02) // some space between slices
.sort(null) //No! we don't want to order it by size
.value(function(d) {
return d.value;
}); //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")
.attr("class", "labels") //add a label to each slice
.attr("fill", "grey")
.attr("transform", function(d) {
var c = arc.centroid(d),
xp = c[0],
yp = c[1],
// pythagorean theorem for hypotenuse
hp = Math.sqrt(xp * xp + yp * yp);
return "translate(" + (xp / hp * labelr) + ',' +
(yp / hp * labelr) + ")";
})
.attr("text-anchor", "middle") //center the text on it's origin
.text(function(d, i) {
return `${data[i].value} - ${data[i].label}`;
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.17/d3.min.js"></script>
<div id="chart" style="width: 330px;height: 200px;"></div>
Edit:
If you want the two text strings to be on separate lines you would have to append some <tspan> elements and position them.
var width = 400;
var height = 300; //this is the double because are showing just the half of the pie
var radius = Math.min(width, height) / 2;
var labelr = radius + 30; // radius for label anchor
//array of colors for the pie (in the same order as the dataset)
var color = d3.scale.ordinal()
.range(['#2b5eac', '#0dadd3', '#ffea61', '#ff917e', '#ff3e41']);
data = [{
label: 'CDU',
value: 10
},
{
label: 'SPD',
value: 15
},
{
label: 'Die Grünen',
value: 8
},
{
label: 'Die Mitte',
value: 1
},
{
label: 'Frei Wähler',
value: 3
}
];
var vis = d3.select("#chart")
.append("svg") //create the SVG element inside the <body>
.data([data]) //associate our data with the document
.attr("width", width) //set the width and height of our visualization (these will be attributes of the <svg> tag
.attr("height", height)
.append("svg:g") //make a group to hold our pie chart
.attr('transform', 'translate(' + (width / 2) + ',' + (height / 2) + ')'); //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
.innerRadius(79)
// .outerRadius(radius);
.outerRadius(radius - 10) // full height semi pie
//.innerRadius(0);
var pie = d3.layout.pie() //this will create arc data for us given a list of values
.startAngle(-90 * (Math.PI / 180))
.endAngle(90 * (Math.PI / 180))
.padAngle(.02) // some space between slices
.sort(null) //No! we don't want to order it by size
.value(function(d) {
return d.value;
}); //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
const textEl = arcs.append("svg:text")
.attr("class", "labels") //add a label to each slice
.attr("fill", "grey")
.attr("transform", function(d) {
var c = arc.centroid(d),
xp = c[0],
yp = c[1],
// pythagorean theorem for hypotenuse
hp = Math.sqrt(xp * xp + yp * yp);
return "translate(" + (xp / hp * labelr) + ',' +
(yp / hp * labelr) + ")";
})
.attr("text-anchor", "middle"); //center the text on it's origin
textEl.append('tspan')
.text(function(d, i) {
return data[i].label;
});
textEl.append('tspan')
.text(function(d, i) {
return data[i].value;
})
.attr('x', '0')
.attr('dy', '1.2em');
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.17/d3.min.js"></script>
<div id="chart" style="width: 330px;height: 200px;"></div>

How would I apply an href to the ENTIRE svg?

I've got a page where I build a bunch of pie charts. On each one, I want to add an href to another location on the page.
Currently my code works, but it only applies the href to the individual pieces of the pie chart, as well as the text. So for example, if you click on a ring of the pie chart, it will work like it should, but if you click on the space between the rings, it will not.
The SVG itself is much larger and easier to click, but even though I append the anchor tag to the svg, it only applies to the elements within the SVG. How do I correct this behavior?
function pieChartBuilder(teamName, values) {
var dataset = values;
var trimTitle = teamName.replace(' ', '');
trimTitle = trimTitle.toLowerCase();
var width = 175,
height = 175,
cwidth = 8;
var color = d3.scale.category20();
var pie = d3.layout.pie()
.sort(null);
var arc = d3.svg.arc();
var svg = d3.select("#pieChart").append("svg")
.attr("width", width)
.attr("height", height)
.append("a") // here is where I append the anchor tag to the SVG, but it only applies to the individual elements within.
.attr("href", ("#" + trimTitle))
.append("g")
.attr("transform", "translate(" + width / 2 + "," + height / 2 + ")")
var gs = svg.selectAll("g").data(d3.values(dataset)).enter().append("g");
var path = gs.selectAll("path")
.data(function (d) { return pie(d); })
.enter().append("path")
.attr("fill", function (d, i) { return color(i); })
.attr("d", function (d, i, j) { return arc.innerRadius(5 + cwidth * j).outerRadius(3 + cwidth * (j + 1))(d); });
svg.append("text")
.attr("class", "title")
.attr("x", 0)
.attr("y", (0 - (height / 2.5)))
.attr("text-anchor", "middle")
.style("fill", "#808080")
.text(teamName);
}
I think you just have the selectors the wrong way round. You want to have the svg inside an a tag right?:
d3.select("#pieChart")
.append("a")
.append("svg");
You (1) select the pieChart, then (2) append an a tag to it, then you (3) append the svg to that.

D3 Charts Aligning the Titles and chart positions

I'm using D3 to draw a pie chart in my applicatio. I have created a pie chart with some sample data. But this chart is having alignment issues and adding a title didn't woked as expected,I added x, y attributes to place the chart but it didn't worked. I think I'm adding those to incorrect places.Can someone point out what's wrong here. Following is a sample code. My exact requirement is adding a title to the chart and getting the chart to center.
https://jsfiddle.net/yasirunilan/r8hkpx49/7/
var w = 400;
var h = 400;
var r = h/2;
var color = d3.scale.category20c();
var data = [{"label":"Category A", "value":20},
{"label":"Category B", "value":50},
{"label":"Category C", "value":30}];
var vis = d3.select('#container').append("svg:svg").data([data]).attr("width", w).attr("height", h).append("svg:g").attr("transform", "translate(" + r + "," + r + ")");
var pie = d3.layout.pie().value(function(d){return d.value;});
// declare an arc generator function
var arc = d3.svg.arc().outerRadius(r);
// select paths, use arc generator to draw
var arcs = vis.selectAll("g.slice").data(pie).enter().append("svg:g").attr("class", "slice");
arcs.append("svg:path")
.attr("fill", function(d, i){
return color(i);
})
.attr("d", function (d) {
// log the result of the arc generator to show how cool it is :)
console.log(arc(d));
return arc(d);
});
// add the text
arcs.append("svg:text").attr("transform", function(d){
d.innerRadius = 0;
d.outerRadius = r;
return "translate(" + arc.centroid(d) + ")";}).attr("text-anchor", "middle").text( function(d, i) {
return data[i].label;}
);

D3 Donut with new data will not draw properly

I'm new to D3 and I'm struggling to update my donut chart with new data.
When the data is swapped, the calculated segments are wrong. At first glance the chart might look like a proper donut, but if you inspect the donut you will see that one of the segments is the size of the entire donut.
jsfiddle
I included a commented line of code that completely redraws the donut chart. If you uncomment it, you'll be able to see how the chart is supposed to look.
The update function:
function updateDonut(selector, dataset){
var width = 120;
var height = 120;
var donutWidth = 25;
var radius = Math.min(width, height) / 2;
var color = d3.scale.category20c();
var pie = d3.layout.pie()
.value(function(d) {
return d.values;
})
.sort(null);
var arc = d3.svg.arc()
.innerRadius(radius - donutWidth)
.outerRadius(radius);
var svg = d3.select(selector).select("svg > g");
if(svg.empty()){
svg = d3.select(selector)
.append('svg')
.attr('width', width)
.attr('height', height)
.append('g')
.attr('transform', 'translate(' + (width / 2) + ',' + (height / 2) + ')');
}
/*Uncommenting below line shows donut should look like*/
//svg.selectAll("path").remove();
var path = svg.selectAll("path");
path = path.data(pie(dataset));
path.enter().append("path")
.attr("fill", function(d, i) { return color(i) })
.attr("d", arc)
path.exit().remove()
}
whenever you switch dataset, you either need to remove the existing svg structure or reset them. You can remove them like this and the remaining code will create a new structure:
if(d3.select(selector))
d3.select(selector).select("svg").remove();
Here's the working fiddle: https://jsfiddle.net/swevens/Lb2temc8/17/

Single Stacked Bar Graph Data Setup?

I'm trying to make a singular column for a bar graph in d3.js, the purpose of which is to bar-graph the coefficients of the other line graph in my program. I'm familiar with how they are made when the data is in .csv format, but in this case right now I'm trying to make it from three variables. The three variables are:
var xtwo;
var xone;
var xzero;
which have values put into them in a later part. I've built a skeleton based on what I know and have seen, which is right here:
//Bar Graph
var barmargin = {
top: 20,
right: 20,
bottom: 30,
left: 60
},
barwidth = 500 - barmargin.left - barmargin.right,
barheight = 350 - barmargin.top - barmargin.bottom;
//X scale
var barx = d3.scale.ordinal()
.rangeRoundBands([0, barwidth], .1);
//Y scale
var bary = d3.scale.linear()
.rangeRound([barheight, 0]);
//bar graph colors
var color = d3.scale.ordinal()
.range(["#FF5C33", "#F48C00", "#FFFF5C"]);
// Use X scale to set a bottom axis
var barxAxis = d3.svg.axis()
.scale(barx)
.orient("bottom");
// Same for y
var baryAxis = d3.svg.axis()
.scale(bary)
.orient("left")
.tickFormat(d3.format(".2s"));
// Addchart to the #chart div
var svg = d3.select("#chart").append("svg")
.attr("width", barwidth + barmargin.left + barmargin.right)
.attr("height", barheight + barmargin.top + barmargin.bottom)
.append("g")
.attr("transform", "translate(" + barmargin.left + "," + barmargin.top + ")");
//Where data sorting happens normally
var bardata.data([xzero, xone, xtwo]);
//Y domain is from zero to 5
y.domain([0, 5]);
svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + barheight + ")")
.call(barxAxis);
svg.append("g")
.attr("class", "y axis")
.call(baryAxis);
bardata.selectAll("rect")
.data(function(d) {
return d.types;
})
.enter().append("rect")
.attr("width", barx.rangeBand())
.attr("y", function(d) {
return bary(d.y1);
})
.attr("height", function(d) {
return bary(d.y0) - bary(d.y1);
})
.style("fill", function(d) {
return color(d.name);
});
but I can't really figure out how to make it work correctly. I thought that I could manually make the .data but it seems to not be working that way.
Full code if necessary: https://jsfiddle.net/tqj5maza/1/
Broadly speaking: you want to create three bars, sat on top of each other, from three different values. The three values will be enough to scale the bars, but they in themselves won't be enough to position the bars- each bar needs to be offset by the size of the bars that have gone before.
d3 can only read the values that are already in the data you send it- you can't really access the previous values as you go, as each datum is bound to a separate element. Thus, what you need to do is to create some new data, which has all the numbers required to display it.
Here's one way that you might do that:
var canvas = d3.select("#canvas").append("svg").attr({width: 400, height: 400})
var values = [50, 90, 30]
var colours = ['#FA0', '#0AF', '#AF0']
var data = []
var yOffset = 0
//Process the data
for(var i = 0; i < values.length; i++) {
var datum = {
value : values[i],
colour : colours[i],
x: 0,
y: yOffset
}
yOffset += values[i]
data.push(datum)
}
var bars = canvas.selectAll('rect').data(data)
bars
.enter()
.append('rect')
.attr({
width : 30,
height : function(d) {
return d.value
},
y : function(d) {
return d.y //
}
})
.style({
fill : function(d) {
return d.colour
}
})
http://jsfiddle.net/r3sazt7m/
d3's layout functions all do more or less this- you pass them a set of data, and they return new data containing the values that the SVG drawing instructions require.

Categories