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@nbremer /.block
Last active Dec 10, 2018

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Radar Chart Redesign
height: 600
license: mit

A new design for a radar chart in D3.js. You can read more about in on the blog I wrote "A different look for the D3 radar chart"

An older version of a radar chart that I adjusted two years ago when I was just starting to learn D3.js can be found here

<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html;charset=utf-8"/ >
<title>Smoothed D3.js Radar Chart</title>
<!-- Google fonts -->
<link href='http://fonts.googleapis.com/css?family=Open+Sans:400,300' rel='stylesheet' type='text/css'>
<link href='https://fonts.googleapis.com/css?family=Raleway' rel='stylesheet' type='text/css'>
<!-- D3.js -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.6/d3.min.js" charset="utf-8"></script>
<style>
body {
font-family: 'Open Sans', sans-serif;
font-size: 11px;
font-weight: 300;
fill: #242424;
text-align: center;
text-shadow: 0 1px 0 #fff, 1px 0 0 #fff, -1px 0 0 #fff, 0 -1px 0 #fff;
cursor: default;
}
.legend {
font-family: 'Raleway', sans-serif;
fill: #333333;
}
.tooltip {
fill: #333333;
}
</style>
</head>
<body>
<div class="radarChart"></div>
<script src="radarChart.js"></script>
<script>
/* Radar chart design created by Nadieh Bremer - VisualCinnamon.com */
//////////////////////////////////////////////////////////////
//////////////////////// Set-Up //////////////////////////////
//////////////////////////////////////////////////////////////
var margin = {top: 100, right: 100, bottom: 100, left: 100},
width = Math.min(700, window.innerWidth - 10) - margin.left - margin.right,
height = Math.min(width, window.innerHeight - margin.top - margin.bottom - 20);
//////////////////////////////////////////////////////////////
////////////////////////// Data //////////////////////////////
//////////////////////////////////////////////////////////////
var data = [
[//iPhone
{axis:"Battery Life",value:0.22},
{axis:"Brand",value:0.28},
{axis:"Contract Cost",value:0.29},
{axis:"Design And Quality",value:0.17},
{axis:"Have Internet Connectivity",value:0.22},
{axis:"Large Screen",value:0.02},
{axis:"Price Of Device",value:0.21},
{axis:"To Be A Smartphone",value:0.50}
],[//Samsung
{axis:"Battery Life",value:0.27},
{axis:"Brand",value:0.16},
{axis:"Contract Cost",value:0.35},
{axis:"Design And Quality",value:0.13},
{axis:"Have Internet Connectivity",value:0.20},
{axis:"Large Screen",value:0.13},
{axis:"Price Of Device",value:0.35},
{axis:"To Be A Smartphone",value:0.38}
],[//Nokia Smartphone
{axis:"Battery Life",value:0.26},
{axis:"Brand",value:0.10},
{axis:"Contract Cost",value:0.30},
{axis:"Design And Quality",value:0.14},
{axis:"Have Internet Connectivity",value:0.22},
{axis:"Large Screen",value:0.04},
{axis:"Price Of Device",value:0.41},
{axis:"To Be A Smartphone",value:0.30}
]
];
//////////////////////////////////////////////////////////////
//////////////////// Draw the Chart //////////////////////////
//////////////////////////////////////////////////////////////
var color = d3.scale.ordinal()
.range(["#EDC951","#CC333F","#00A0B0"]);
var radarChartOptions = {
w: width,
h: height,
margin: margin,
maxValue: 0.5,
levels: 5,
roundStrokes: true,
color: color
};
//Call function to draw the Radar chart
RadarChart(".radarChart", data, radarChartOptions);
</script>
</body>
</html>
/////////////////////////////////////////////////////////
/////////////// The Radar Chart Function ////////////////
/////////////// Written by Nadieh Bremer ////////////////
////////////////// VisualCinnamon.com ///////////////////
/////////// Inspired by the code of alangrafu ///////////
/////////////////////////////////////////////////////////
function RadarChart(id, data, options) {
var cfg = {
w: 600, //Width of the circle
h: 600, //Height of the circle
margin: {top: 20, right: 20, bottom: 20, left: 20}, //The margins of the SVG
levels: 3, //How many levels or inner circles should there be drawn
maxValue: 0, //What is the value that the biggest circle will represent
labelFactor: 1.25, //How much farther than the radius of the outer circle should the labels be placed
wrapWidth: 60, //The number of pixels after which a label needs to be given a new line
opacityArea: 0.35, //The opacity of the area of the blob
dotRadius: 4, //The size of the colored circles of each blog
opacityCircles: 0.1, //The opacity of the circles of each blob
strokeWidth: 2, //The width of the stroke around each blob
roundStrokes: false, //If true the area and stroke will follow a round path (cardinal-closed)
color: d3.scale.category10() //Color function
};
//Put all of the options into a variable called cfg
if('undefined' !== typeof options){
for(var i in options){
if('undefined' !== typeof options[i]){ cfg[i] = options[i]; }
}//for i
}//if
//If the supplied maxValue is smaller than the actual one, replace by the max in the data
var maxValue = Math.max(cfg.maxValue, d3.max(data, function(i){return d3.max(i.map(function(o){return o.value;}))}));
var allAxis = (data[0].map(function(i, j){return i.axis})), //Names of each axis
total = allAxis.length, //The number of different axes
radius = Math.min(cfg.w/2, cfg.h/2), //Radius of the outermost circle
Format = d3.format('%'), //Percentage formatting
angleSlice = Math.PI * 2 / total; //The width in radians of each "slice"
//Scale for the radius
var rScale = d3.scale.linear()
.range([0, radius])
.domain([0, maxValue]);
/////////////////////////////////////////////////////////
//////////// Create the container SVG and g /////////////
/////////////////////////////////////////////////////////
//Remove whatever chart with the same id/class was present before
d3.select(id).select("svg").remove();
//Initiate the radar chart SVG
var svg = d3.select(id).append("svg")
.attr("width", cfg.w + cfg.margin.left + cfg.margin.right)
.attr("height", cfg.h + cfg.margin.top + cfg.margin.bottom)
.attr("class", "radar"+id);
//Append a g element
var g = svg.append("g")
.attr("transform", "translate(" + (cfg.w/2 + cfg.margin.left) + "," + (cfg.h/2 + cfg.margin.top) + ")");
/////////////////////////////////////////////////////////
////////// Glow filter for some extra pizzazz ///////////
/////////////////////////////////////////////////////////
//Filter for the outside glow
var filter = g.append('defs').append('filter').attr('id','glow'),
feGaussianBlur = filter.append('feGaussianBlur').attr('stdDeviation','2.5').attr('result','coloredBlur'),
feMerge = filter.append('feMerge'),
feMergeNode_1 = feMerge.append('feMergeNode').attr('in','coloredBlur'),
feMergeNode_2 = feMerge.append('feMergeNode').attr('in','SourceGraphic');
/////////////////////////////////////////////////////////
/////////////// Draw the Circular grid //////////////////
/////////////////////////////////////////////////////////
//Wrapper for the grid & axes
var axisGrid = g.append("g").attr("class", "axisWrapper");
//Draw the background circles
axisGrid.selectAll(".levels")
.data(d3.range(1,(cfg.levels+1)).reverse())
.enter()
.append("circle")
.attr("class", "gridCircle")
.attr("r", function(d, i){return radius/cfg.levels*d;})
.style("fill", "#CDCDCD")
.style("stroke", "#CDCDCD")
.style("fill-opacity", cfg.opacityCircles)
.style("filter" , "url(#glow)");
//Text indicating at what % each level is
axisGrid.selectAll(".axisLabel")
.data(d3.range(1,(cfg.levels+1)).reverse())
.enter().append("text")
.attr("class", "axisLabel")
.attr("x", 4)
.attr("y", function(d){return -d*radius/cfg.levels;})
.attr("dy", "0.4em")
.style("font-size", "10px")
.attr("fill", "#737373")
.text(function(d,i) { return Format(maxValue * d/cfg.levels); });
/////////////////////////////////////////////////////////
//////////////////// Draw the axes //////////////////////
/////////////////////////////////////////////////////////
//Create the straight lines radiating outward from the center
var axis = axisGrid.selectAll(".axis")
.data(allAxis)
.enter()
.append("g")
.attr("class", "axis");
//Append the lines
axis.append("line")
.attr("x1", 0)
.attr("y1", 0)
.attr("x2", function(d, i){ return rScale(maxValue*1.1) * Math.cos(angleSlice*i - Math.PI/2); })
.attr("y2", function(d, i){ return rScale(maxValue*1.1) * Math.sin(angleSlice*i - Math.PI/2); })
.attr("class", "line")
.style("stroke", "white")
.style("stroke-width", "2px");
//Append the labels at each axis
axis.append("text")
.attr("class", "legend")
.style("font-size", "11px")
.attr("text-anchor", "middle")
.attr("dy", "0.35em")
.attr("x", function(d, i){ return rScale(maxValue * cfg.labelFactor) * Math.cos(angleSlice*i - Math.PI/2); })
.attr("y", function(d, i){ return rScale(maxValue * cfg.labelFactor) * Math.sin(angleSlice*i - Math.PI/2); })
.text(function(d){return d})
.call(wrap, cfg.wrapWidth);
/////////////////////////////////////////////////////////
///////////// Draw the radar chart blobs ////////////////
/////////////////////////////////////////////////////////
//The radial line function
var radarLine = d3.svg.line.radial()
.interpolate("linear-closed")
.radius(function(d) { return rScale(d.value); })
.angle(function(d,i) { return i*angleSlice; });
if(cfg.roundStrokes) {
radarLine.interpolate("cardinal-closed");
}
//Create a wrapper for the blobs
var blobWrapper = g.selectAll(".radarWrapper")
.data(data)
.enter().append("g")
.attr("class", "radarWrapper");
//Append the backgrounds
blobWrapper
.append("path")
.attr("class", "radarArea")
.attr("d", function(d,i) { return radarLine(d); })
.style("fill", function(d,i) { return cfg.color(i); })
.style("fill-opacity", cfg.opacityArea)
.on('mouseover', function (d,i){
//Dim all blobs
d3.selectAll(".radarArea")
.transition().duration(200)
.style("fill-opacity", 0.1);
//Bring back the hovered over blob
d3.select(this)
.transition().duration(200)
.style("fill-opacity", 0.7);
})
.on('mouseout', function(){
//Bring back all blobs
d3.selectAll(".radarArea")
.transition().duration(200)
.style("fill-opacity", cfg.opacityArea);
});
//Create the outlines
blobWrapper.append("path")
.attr("class", "radarStroke")
.attr("d", function(d,i) { return radarLine(d); })
.style("stroke-width", cfg.strokeWidth + "px")
.style("stroke", function(d,i) { return cfg.color(i); })
.style("fill", "none")
.style("filter" , "url(#glow)");
//Append the circles
blobWrapper.selectAll(".radarCircle")
.data(function(d,i) { return d; })
.enter().append("circle")
.attr("class", "radarCircle")
.attr("r", cfg.dotRadius)
.attr("cx", function(d,i){ return rScale(d.value) * Math.cos(angleSlice*i - Math.PI/2); })
.attr("cy", function(d,i){ return rScale(d.value) * Math.sin(angleSlice*i - Math.PI/2); })
.style("fill", function(d,i,j) { return cfg.color(j); })
.style("fill-opacity", 0.8);
/////////////////////////////////////////////////////////
//////// Append invisible circles for tooltip ///////////
/////////////////////////////////////////////////////////
//Wrapper for the invisible circles on top
var blobCircleWrapper = g.selectAll(".radarCircleWrapper")
.data(data)
.enter().append("g")
.attr("class", "radarCircleWrapper");
//Append a set of invisible circles on top for the mouseover pop-up
blobCircleWrapper.selectAll(".radarInvisibleCircle")
.data(function(d,i) { return d; })
.enter().append("circle")
.attr("class", "radarInvisibleCircle")
.attr("r", cfg.dotRadius*1.5)
.attr("cx", function(d,i){ return rScale(d.value) * Math.cos(angleSlice*i - Math.PI/2); })
.attr("cy", function(d,i){ return rScale(d.value) * Math.sin(angleSlice*i - Math.PI/2); })
.style("fill", "none")
.style("pointer-events", "all")
.on("mouseover", function(d,i) {
newX = parseFloat(d3.select(this).attr('cx')) - 10;
newY = parseFloat(d3.select(this).attr('cy')) - 10;
tooltip
.attr('x', newX)
.attr('y', newY)
.text(Format(d.value))
.transition().duration(200)
.style('opacity', 1);
})
.on("mouseout", function(){
tooltip.transition().duration(200)
.style("opacity", 0);
});
//Set up the small tooltip for when you hover over a circle
var tooltip = g.append("text")
.attr("class", "tooltip")
.style("opacity", 0);
/////////////////////////////////////////////////////////
/////////////////// Helper Function /////////////////////
/////////////////////////////////////////////////////////
//Taken from http://bl.ocks.org/mbostock/7555321
//Wraps SVG text
function wrap(text, width) {
text.each(function() {
var text = d3.select(this),
words = text.text().split(/\s+/).reverse(),
word,
line = [],
lineNumber = 0,
lineHeight = 1.4, // ems
y = text.attr("y"),
x = text.attr("x"),
dy = parseFloat(text.attr("dy")),
tspan = text.text(null).append("tspan").attr("x", x).attr("y", y).attr("dy", dy + "em");
while (word = words.pop()) {
line.push(word);
tspan.text(line.join(" "));
if (tspan.node().getComputedTextLength() > width) {
line.pop();
tspan.text(line.join(" "));
line = [word];
tspan = text.append("tspan").attr("x", x).attr("y", y).attr("dy", ++lineNumber * lineHeight + dy + "em").text(word);
}
}
});
}//wrap
}//RadarChart
@OverlordQ

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OverlordQ commented Sep 14, 2016

I notice this one leaves out a legend telling what each color is for

@marcusguttenplan

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marcusguttenplan commented Jun 8, 2017

This is awesome! I started poking this today to practice styling d3, just wanted to share a little fix for something I ran into.

I wanted to remove the stroke as config'd in strokeWidth entirely, but that broke the great hover opacity effect. Instead of hackily removing the stroke from blobWrapper which was the first solution I found, I figured an if statement would be better. Had some trouble with vanilla JS logic at first trying to put the style inside of the if statement, but after some trial and error got this if inside of the style:

.style("stroke", function(d, i) {
            if (cfg.strokeWidth === 0) {return;}
            else {return cfg.color(i);}
        })

complete blobWrapper

 blobWrapper.append("path")
        .attr("class", "radarStroke")
        .attr("d", function(d,i) { return radarLine(d); })
        .style("stroke-width", cfg.strokeWidth + "px")

        // add if statement for stroke=0
        .style("stroke", function(d, i) {
            if (cfg.strokeWidth === 0) {return;}
            else {return cfg.color(i);}
        })

        .style("fill", "none")
        .style("filter" , "url(#glow)");

super simple and affords a bit more control! Just wanted to share in case this helps anyone else in the future. Thanks for a great block!

@tdharmon

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tdharmon commented Aug 16, 2017

There are some parts of this that are out of date with the current version of D3 (v4). Here are the changes that I made to get this working:

  • line 22: color: d3.scale.category10() becomes color: d3.scaleOrdinal(d3.schemeCategory10)
  • line 42: var rScale = d3.scale.linear() becomes var rScale = d3.scaleLinear()
  • line 140: var radarLine = d3.svg.line.radial().interpolate("linear-closed") becomes var radarLine = d3.lineRadial().curve(d3.curveBasisClosed)
  • line 146: radarLine.interpolate("cardinal-closed") becomes radarLine.curve(d3.curveCardinalClosed)

There are some minor quirks to fix (I'll add a note here once I figure out the fix to those), but those are the breaking changes made from D3 v3 to v4.

@cbertolasio

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cbertolasio commented Dec 18, 2017

This gist is awesome, thanks for sharing. I refactored it for my own use, more for a polar graph where my data has a given value for a bearing. I was curious if anyone had any ideas regarding:

  • why is the / what makes the Y axis negative / inverted?
  • if I wanted to look into zooming into and redrawing the circles that are plotted, what transforms, etc would I start looking into?

In my code, instead of subtracting Pi/2 I used sin for X and cos for Y, like so:

.attr('x', function (d, i) {
	return rScale(maxValue * cfg.labelFactor) * Math.sin(angleSlice * i);
})
.attr('y', function (d, i) {
	return -(rScale(maxValue * cfg.labelFactor) * Math.cos(angleSlice * i));
})

.attr('cx', function (d) {
	return rScale(d.value) * Math.sin(toRadians(d.bearing));
})
.attr('cy', function (d) {
	return rScale(d.value) * -Math.cos(toRadians(d.bearing));
})

Here is what my chart looks like. Thanks again - this gist really helped me get going.
image

@bwgalloway

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bwgalloway commented Jan 30, 2018

Any tips on allowing this to use a slider to control the data?

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