app/assets/javascripts/d3-charts/radar_chart.js
/////////////////////////////////////////////////////////
/////////////// The Radar Chart Function ////////////////
/////////////// Written by Nadieh Bremer ////////////////
////////////////// VisualCinnamon.com ///////////////////
/////////// Inspired by the code of alangrafu ///////////
/////////// Ported to d3.js v4 by drusepth ///////////
/////////////////////////////////////////////////////////
function RadarChart(id, data, options) {
var cfg = {
w: 600, //Width of the circle
h: 600, //Height of the circle
margin: {top: 100, right: 100, bottom: 100, left: 100}, //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.schemeCategory10 //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(',d'), //Percentage formatting
angleSlice = Math.PI * 2 / total; //The width in radians of each "slice"
//Scale for the radius
var rScale = d3.scaleLinear()
.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", '100%')
.attr("height", cfg.h + cfg.margin.top + cfg.margin.bottom + 200)
.attr('viewBox','100 -50 ' +
Math.min(cfg.w, cfg.h + 100) + ' ' +
Math.min(cfg.w, cfg.h))
.attr('preserveAspectRatio', 'xMinYMin')
.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.lineRadial()
.radius(function(d) { return rScale(d.value); })
.angle(function(d,i) { return i*angleSlice; });
if(cfg.roundStrokes) {
radarLine.curve(d3.curveCardinal);
}
//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