i'm trying to somehow sweep in a half-donut-chart, meaning starting with a blank screen the chart starts drawing at -90 degree (or 270) and performs a halfcircle until reaching 90 degree. the code looks like:
var width = 800;
var height = 400;
var radius = 300;
var grad=Math.PI/180;
var data = [30, 14, 4, 4, 5];
var color = d3.scale.category20();
var svg = d3.select("body").append("svg").attr("width", width).attr("height",
`height).append("g").attr("transform", "translate(" + radius*1.5 + "," + radius*1.5 +
")");
var arc = d3.svg.arc().innerRadius(radius - 100).outerRadius(radius - 20);
var pie = d3.layout.pie().sort(null);
svg.selectAll("path").data(pie(data)).enter().append("path").attr("d",
arc).attr("fill",
function(d, i) { return color(i); }).transition().duration(500).attrTween("d", sweep);
function sweep(a) {
var i = d3.interpolate({startAngle: -90*grad, endAngle: -90*grad},{startAngle: -90*grad, endAngle: 90*grad});
return function(t) {
return arc(i(t));
};
}
looking at several examples i managed to get the animation, however, i fail at binding (or converting) the data to the arc. my feeling is that there is only one path drawn and then it stops.
if i change the interpolation to start/end -90/90 and a, i get different colors but not all of them. adding the start/end-angle to the pie-var gives me a transition where a one-colored-arc is shown at the beginning and then the other parts slide in (which would be correct if there was no arc at the beginning - the proportions also seem a bit wrong). setting the initial color to white does not help because then everything stays white.
i'm afraid i'm missing an obvious point, but so far i'm stuck, maybe someone can point me in the right direction.
after quite some variations and tests it somehow started to work, using these to lines of code:
var pie = d3.layout.pie().sort(null).startAngle(-90*grad).endAngle(90*grad);
var i = d3.interpolate({startAngle: -90*grad, endAngle: -90*grad},a);
one final "problem" was that the height of the svg was too small and so some segments got cut off, so changing it to
var height = 800;
ended my search. thanks for any considerations.
A small typo on the
var svg = d3.select("body").append("svg").attr("width", width).attr("height", `height)
should be:
var svg = d3.select("body").append("svg").attr("width", width).attr("height", height)
Related
I am using attempting to use d3.forceSimulation that applies a force to the y position of the chart circles to keep them from overlapping.
the final chart would look something like this -
I have been following some examples but am unable to get the y positions to adjust in the right way. Unfortunately, I have no idea where this is going wrong. Any hint in the right direction would be greatly appreciated!
So far, this is my code:
//ADDING SKELETON FOR THE CHART//
let width = 900;
let height = 300;
let margin = {x: 50, y:20};
let chartDiv = d3.select('body').append('div').attr('id', 'bubble-chart');
let svg = chartDiv.append('svg');
svg.attr('height', height).attr('width', width + margin.x);
//SCALES FOR X POSITION//
let posScale = d3.scaleLinear().domain([(0-overallMax), overallMax]);
posScale.range([0, width]);
//SCALES FOR COLOR//
let colorScale = d3.scaleOrdinal().domain(groupData.map(g=> g[0])).range(d3.schemeSet3);
//SCALE FOR CIRCLE SIZE//
let circleScale = d3.scaleLinear().domain([d3.min(data.map(d=> +d.total)), d3.max(data.map(d=> +d.total))])
.range([3, 10]);
//SIMULATION PART
let simulation = d3.forceSimulation().nodes(data)
.force('center', d=> d3.forceCenter(posScale(d.position), height/2))
//.force('charge', d3.forceManyBody().strength(.1))
.force('collision', d3.forceCollide().radius( d => circleScale(+d.total)))
.on('tick',ticked)
let circleGroup = svg.append('g').attr('transform', `translate(${margin.x / 2})`);
let circles = circleGroup.selectAll('circle').data(data).join('circle');
circles.attr('r', (d)=> circleScale(+d.total))//.attr('cx', (d) => posScale(d.position)).attr('cy', 50);
.attr("cx", d=> posScale(d.position))
.attr("cy", height / 2)
circles.attr('fill', (d)=> colorScale(d.category));
circles.style('opacity', '0.5');
// Apply these forces to the nodes and update their positions.
// Once the force algorithm is happy with positions ('alpha' value is low enough), simulations will stop.
function ticked(){
circles.attr("cy", d=> d.y).attr('cx', d=> posScale(d.position));
}
This is what my chart looks like with the above code:
Thank you in advance!
This is not how one creates a beeswarm chart (the technical name of this kind of data visualisation). You should use forceX and forceY in the simulation to set the positions. In your case:
let simulation = d3.forceSimulation().nodes(data)
.force("x", d3.forceX(function(d) {
return posScale(d.position);
}).strength(foo))
.force("y", d3.forceY(50).strength(bar))
.force('collision', d3.forceCollide().radius( d => circleScale(d.total)))
.on('tick',ticked)
Then, adjust the strengths (foo and bar) according to your needs, and change the ticked function to use the x and y properties provided by the simulation.
In the d3.v4 documentation the following is stated:
To generate ticks every fifteen minutes with a time scale, say:
axis.tickArguments([d3.timeMinute.every(15)]);
Is there a similar approach that can be used with values other than time? I am plotting sine and cosine curves, so I'd like the ticks to begin at -2*Math.PI, end at 2*Math.PI, and between these values I'd like a tick to occur every Math.PI/2. I could, of course, explicitly compute the tick values and supply them to the tickValue method; however, if there is a simpler way to accomplish this, as in the time-related example quoted above, I'd prefer to use that.
Setting the end ticks and specifying the precise space of the ticks in a linear scale is a pain in the neck. The reason is that D3 axis generator was created in such a way that the ticks are automatically generated and spaced. So, what is handy for someone who doesn't care too much for customisation can be a nuisance for those that want a precise customisation.
My solution here is a hack: create two scales, one linear scale that you'll use to plot your data, and a second scale, that you'll use only to make the axis and whose values you can set at your will. Here, I choose a scalePoint() for the ordinal scale.
Something like this:
var realScale = d3.scaleLinear()
.range([10,width-10])
.domain([-2*Math.PI, 2*Math.PI]);
var axisScale = d3.scalePoint()
.range([10,width-10])
.domain(["-2 \u03c0", "-1.5 \u03c0", "-\u03c0", "-0.5 \u03c0", "0",
"0.5 \u03c0", "\u03c0", "1.5 \u03c0", "2 \u03c0"]);
Don't mind the \u03c0, that's just π (pi) in Unicode.
Check this demo, hover over the circles to see their positions:
var width = 500,
height = 150;
var data = [-2, -1, 0, 0.5, 1.5];
var realScale = d3.scaleLinear()
.range([10, width - 10])
.domain([-2 * Math.PI, 2 * Math.PI]);
var axisScale = d3.scalePoint()
.range([10, width - 10])
.domain(["-2 \u03c0", "-1.5 \u03c0", "-\u03c0", "-0.5 \u03c0", "0", "0.5 \u03c0", "\u03c0", "1.5 \u03c0", "2 \u03c0"]);
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height);
var circles = svg.selectAll("circle").data(data)
.enter()
.append("circle")
.attr("r", 8)
.attr("fill", "teal")
.attr("cy", 50)
.attr("cx", function(d) {
return realScale(d * Math.PI)
})
.append("title")
.text(function(d) {
return "this circle is at " + d + " \u03c0"
});
var axis = d3.axisBottom(axisScale);
var gX = svg.append("g")
.attr("transform", "translate(0,100)")
.call(axis);
<script src="https://d3js.org/d3.v4.min.js"></script>
I was able to implement an x axis in units of PI/2, under program control (not manually laid out), by targetting the D3 tickValues and tickFormat methods. The call to tickValues sets the ticks at intervals of PI/2. The call to tickFormat generates appropriate tick labels. You can view the complete code on GitHub:
https://github.com/quantbo/sine_cosine
My solution is to customise tickValues and tickFormat. Only 1 scale is needed, and delegate d3.ticks function to give me the new tickValues that are proportional to Math.PI.
const piChar = String.fromCharCode(960);
const tickFormat = val => {
const piVal = val / Math.PI;
return piVal + piChar;
};
const convertSIToTrig = siDomain => {
const trigMin = siDomain[0] / Math.PI;
const trigMax = siDomain[1] / Math.PI;
return d3.ticks(trigMin, trigMax, 10).map(v => v * Math.PI);
};
const xScale = d3.scaleLinear().domain([-Math.PI * 2, Math.PI * 2]).range([0, 600]);
const xAxis = d3.axisBottom(xScale)
.tickValues(convertSIToTrig(xScale.domain()))
.tickFormat(tickFormat);
This way if your xScale's domain were changed via zoom/pan, the new tickValues are nicely generated with smaller/bigger interval
My goal is to make a bar chart that demonstrates the number of jobs advertised in particular locations.
I'm using this code, it draws on d3 and also dimple:
<script type="text/javascript">
function draw(data) {
/*
D3.js setup code
*/
"use strict";
var margin = 75,
width = 1400 - margin,
height = 600 - margin;
var svg = d3.select("body")
.append("svg")
.attr("width", width + margin)
.attr("height", height + margin)
.append('g')
.attr('class','chart');
/*
Dimple.js Chart construction code
*/
var myChart = new dimple.chart(svg, data);
myChart.addCategoryAxis("x", "Location");
myChart.addMeasureAxis("y", "Jobs");
myChart.addSeries(null, dimple.plot.bar);
myChart.draw();
};
</script>
It more or less works, but the thing is- the result is pretty useless because the X axis is so crowded that each individual location is essentially invisible.
Is there a way to enforce some reasonable amount of spacing there so that the different locations remain legible in such a way that it can withstand more records being added at a later date- so- with some kind of dynamism.
Ok, so- on the advice of #thisOneGuy I started playing around with increasing the width, and it worked.
At first I tried to increase the width too much and the chart just disappeared (if anyone knows why that happened I would be interested to hear about it in the comments perhaps)
from width = 1400 - margin, to width = 14000 - margin, it disappears
but width = 9000 - margin, was ok.
you can find the result here
I'm very new to d3 and trying to learn by building a visualization.
My goal right now is to make a circle and color the circle based on some temporal data. I've made the circle, and want to add a timescale to it. The circle I have created fine using d3.arc() on an svg element. I have also created a time scale (seen below). My question is, how can I "attach" this time scale to the circle? I want to be able to say that at xyz point in time, my data holds this value, so now color the circle based on a color scale.
Or...am I going about this wrong?
var time = d3.scale.ordinal()
.domain(d3.extent(data, function(d) {
return d.date;
}))
I think you may need to use a quantitative scale instead of ordinal.
https://github.com/mbostock/d3/wiki/Ordinal-Scales says -
Ordinal scales have a discrete domain, such as a set of names or categories
and in your code, you use the "extent" of the date property, which only gives you 2 values - the earliest and most recent date in your data. That is a discrete domain, but a very limited one, and wouldn't represent your data very well. The scale will only output at most 2 values.
var now = Date.now();
var then = now - 1000;
var colors = d3.scale.ordinal()
.domain([then, now])
.range(['#ff0000','#0000ff']);
colors(then); // red
colors(now); // blue
colors(now - 500); // red... expecting violet
change 'ordinal' to 'linear' and leave the rest as is.
var now = Date.now();
var then = now - 1000;
var colors = d3.scale.linear()
.domain([then, now])
.range(['#ff0000','#0000ff']);
colors(then); // red
colors(now); // blue
colors(now - 500); // violet
The tricky part (at least for me) was remembering that the output of d3.scale.linear() (the 'colors' variable above) is a function. It can be called just like any other function.
var fakeData = d3.range(then, now, 10);
var svg = d3.select('body')
.append('svg')
.attr({ height: 500, width: 500 });
var circle = svg.append('circle')
.attr({ r: 100, cx: 250, cy: 250 });
function changeTime(time){
circle.attr('fill', colors(time));
}
I am running D3.js to draw a progress bar in circle shape, which you will see the demo on jsfiddle , the progress bar has a transition animation.
The main code is
var width = 960,
height = 500,
twoPi = 2 * Math.PI,
progress = 0,
total = 1308573, // must be hard-coded if server doesn't report Content-Length
formatPercent = d3.format(".0%");
var arc = d3.svg.arc()
.startAngle(0)
.innerRadius(0)
.outerRadius(240);
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height)
.append("g")
.attr("transform", "translate(" + width / 2 + "," + height / 2 + ")");
var meter = svg.append("g")
.attr("class", "progress-meter");
meter.append("path")
.attr("class", "background")
.attr("d", arc.endAngle(twoPi));
var foreground = meter.append("path")
.attr("class", "foreground");
foreground.attr("d", arc.endAngle(twoPi * 0))
foreground.transition().duration(1500).attr("d", arc.endAngle( twoPi * 2/3 ));
var text = meter.append("text")
.attr("text-anchor", "middle")
.attr("dy", ".35em");
to make the progress bar move, we only need to change to the arc.endAngle(), which is on the line.
foreground.transition().duration(1500).attr("d", arc.endAngle( twoPi * 2/3 ));
if the angle is less than 180, ( endangle < twoPi*1/2), then the animation works fine, but when the angle is larger than 180, so means endangle >= twoPi*1/2. then the animation would not show, and if you look at the console, you will find many errors on d3.js
Error: Problem parsing d="M1.1633760361312584e-14,-190A190,190 0 1.481481481481482e-7,1 -0.000022772330200401806,-189.9999883969182L0,0Z" meeting.html:1
2
Error: Problem parsing d="M1.1633760361312584e-14,-190A190,190 0 2.56e-7,1 -0.00003935058659476369,-189.99997994987467L0,0Z"
so what is the exact problem for this, how to solve it
It doesn't work because you can't use the standard transition for radial paths. By default, it simply interpolates the numbers without knowing what they represent, so in your case, you end up with some really small numbers (e.g. 1.1633760361312584e-14) which Javascript represents in exponential notation which is not valid for SVG paths.
The solution is to use a custom tween function that knows how to interpolate arcs:
function arcTween() {
var i = d3.interpolate(0, twoPi * 2/3);
return function(t) {
return arc.endAngle(i(t))();
};
}
Complete example here. You may also be interested in this example, which shows how to do it with data bound to the paths.