Develop Reference

d3 pie: redraw label on path change

I'm using d3 to draw a pie with radio button to change the paths showed. My problem is to recalculate the label position based on the new paths. On load the labels are drawn correctly but on click the position still the same of first load.
I think that the problem is that the g's take only the first data value and i don't know how to say to take the current data values.
The function that draw the labels is
//Labels
d3.selectAll("g").select("text").transition()
.ease("linear")
.duration(500)
.style("opacity", 0).remove();
svg.selectAll("g").append("text")
.attr("transform", function (d) {
var c = arc.centroid(d),
x = c[0],
y = c[1],
// pythagorean theorem for hypotenuse
h = Math.sqrt(x * x + y * y);
return "translate(" + (x / h * labelr) + ',' +
(y / h * labelr) + ")";
})
.attr("dy", ".35em")
.style("opacity", 0)
.style("fill", "#000")
.style("font-size", 12)
.attr("text-anchor", function (d) {
// are we past the center?
return (d.endAngle + d.startAngle) / 2 > Math.PI ?
"end" : "start";
})
.text(function (d) { return d.data.label; })
.transition()
.ease("linear")
.delay(1000)
.duration(500)
.style("opacity", 1);
For more info see https://jsfiddle.net/w0ckw4tb/
Thanks

Just apply new data binding before you append new text nodes:
svg.selectAll("g").data(pie) // <== !!!
.append("text")
.attr("transform" ...
If you did not do it, this code:
.attr("transform", function (d) {
var c = arc.centroid(d),
x = c[0],
y = c[1],
// pythagorean theorem for hypotenuse
h = Math.sqrt(x * x + y * y);
return "translate(" + (x / h * labelr) + ',' +
(y / h * labelr) + ")";
})
returns the same value for transform attribute so the labels remain at the same place.
Check working fiddle.

Curved labels on circular diagram (D3.js)

So, I'm basically trying to make a multilevel circular partition (aka sunburst diagram) with D3.js (v4) and a JSON data.
I placed some labels, which must have different angles depending of their levels (circles) on the partition :
- Level < 3 must be curved and "follow" the arc radius.
- level == 3 must be straight and perpendicular of the arc radius.
I didn't use textPath tags, because I'm not really experienced in SVG and it looks overly complicated to me, and I don't really know how to use it.
here's my code (without the JSON but this is a really classical one, I can add a part of it if it is needed):
var width = 800;
var height = 800;
var radius = 400;
var formatNumber = d3.format(",d");
var x = d3.scaleLinear().range([0, 2 * Math.PI]);
var y = d3.scaleSqrt().range([0, radius]);
var arc = d3.arc()
.startAngle(function(d) { return Math.max(0, Math.min(2 * Math.PI, x(d.x0))); })
.endAngle(function(d) { return Math.max(0, Math.min(2 * Math.PI, x(d.x1))); })
.innerRadius(function(d) { return setRadius("inner", d.data.level); })
.outerRadius(function(d) { return setRadius("outer", d.data.level); });
var svg = d3.select("#chart")
.append("svg")
.attr("width", width)
.attr("height", height)
.append("g")
.attr("transform", "translate(" + width/2 + "," + (height/2) + ")");
var hierarchy = d3.hierarchy(dataset)
.sum(function(d) { return d.size; });
var partition = d3.partition();
svg.selectAll("path")
.data(partition(hierarchy).descendants())
.enter().append("path")
.attr("id", function(d, i){ return "path" + i; })
.attr("d", arc)
.attr("stroke", "white")
.attr("stroke-width", "1px")
.style("fill", function(d) { return (d.data.color) ? d.data.color : 'black'; });
svg.selectAll("text")
.data(partition(hierarchy).descendants())
.enter().append("text")
.attr("transform", function(d){ return setLabelPosition(d); })
.attr("text-anchor", "middle")
.attr("alignment-baseline", "middle")
.attr("font-size", "18px")
.attr("fill", function(d){ return d.data.textcolor; })
.text(function(d){ if(parseInt(d.data.level) > 0 && parseInt(d.data.level) < 4){ return (d.data.name).toUpperCase(); }});
d3.select(self.frameElement)
.style("height", height + "px");
function setRadius(side, level){
var result = 0;
var innerValues = [0, 120, 180, 240, 365];
var outerValues = [0, 180, 240, 365, 400];
if(!side){
throw error;
}
if(side === "inner"){
result = innerValues[level];
}
if(side === "outer"){
result = outerValues[level];
}
return result;
};
function setLabelPosition(d){
var result = '';
var angle = 0;
var centroid = arc.centroid(d);
if(parseInt(d.data.level) === 3){
angle = (180/Math.PI * (arc.startAngle()(d) + arc.endAngle()(d))/2 - 90);
if(angle > 90){
angle = angle - 180;
}
result = "translate(" + centroid + ")rotate(" + angle + ")";
} else {
angle = (180/Math.PI * (arc.startAngle()(d) + arc.endAngle()(d))/2);
result = "translate(" + centroid + ")rotate(" + angle + ")";
}
return result;
};
And the result :
My problem is, how to curve these level 1 & 2 labels (like the one which have a red border), but keep my lvl 3 labels as they currently are.
It's really a pain in the head, and I did many search (on Google and SO) but I didn't find any satisfying answer.
A solution without using a textPath will be awesome if possible, but any advice is welcome.
Many thanks guys and sorry for my English (as you can probably see it's not my birth language).
PS : This is D3.js v4.

How to update a d3 visualization without redrawing every frame?

I am using d3 to create a waveform visualization. I have it looking great, but in my efforts to design this waveform I have paid no attention to doing it an optimized way; I just was trying to get it to work.
setInterval(function() {
if (refresh) waveform();
if (palette_refresh) {
palette_refresh = false;
updateColorPalette();
}
}, options.refresh_rate);
function waveform() {
analyser.getByteFrequencyData(fd);
document.getElementById('wf_box').innerHTML = "";
var data = ... irrelevant implementation details ...
var chart = d3.select("#wf_box").append("svg")
.attr("class", "chart")
.attr("width", "" + percent_offset + "%")
.attr("style", "padding-left:" + (100 - percent_offset) + "%;")
.attr("viewBox", "0 0 " + Math.max(w * data.length, 0) + " " + Math.max(h, 0));
chart.selectAll("rect")
.data(data)
.enter().append("rect")
.attr("x", function(d, i) {
var x_offset = x(i) - Math.max(w * max / 900 - 0.25, 0.1) / 2;
return x_offset;
})
.attr("y", function(d, i) {
var height = y(d * options.bar_height) / h;
return h - Math.pow(Math.max(height, 0.01), 1.5);
})
.attr("width", function(d) {
return '1px';
})
.attr("height", function(d, i) {
var height = y(d * options.bar_height) / h;
return Math.pow(Math.max(height, 0.01), 1.5) + options.bar_y_offset;
});
}
As you can see, I am calling the waveform function repeatedly using options.refresh_rate as my speed. I would imagine that there is a more efficient way of updating the data used in my waveform than deleting the waveform from the DOM and redrawing it every frame. Does anybody have any insight to how I can accomplish this?
Thanks!

Take a look at the enter/exit/update-pattern in d3 https://bl.ocks.org/mbostock/3808218 and see if that can give you a hint.

D3 X-value mouseover - function returns NaN

So I am trying to adapt M Bostock's x-value mouseover example to my own graph, the main difference being that I have multiple series instead of his one. For the moment I'm just trying to get the circles to work. My problem is that when I mouseover the graph (in Firebug) I get the message: Unexpected value translate(<my_x>, NaN) parsing transform attribute. I've tried several different ways to fix it but I get the same response each time. What am I doing wrong?
I have a jsFiddle, and the issue is at the bottom:
var focus = main.append('g')
.attr('class', 'focus')
.style('display', 'none');
var circles = focus.selectAll('circle')
.data(sets) // sets = [{name: ..., values:[{date:..., value:...}, ]}, ]
.enter()
.append('circle')
.attr('class', 'circle')
.attr('r', 4)
.attr('stroke', function (d) {return colour(d.name);});
main.append('rect')
.attr('class', 'overlay')
.attr('width', w)
.attr('height', h)
.on('mouseover', function () {focus.style('dispaly', null);})
.on('mouseout', function () {focus.style('display', 'none');})
.on('mousemove', mousemove);
function mousemove() {
var x0 = x_main.invert(d3.mouse(this)[0]),
i = bisectDate(dataset, x0, 1),
d0 = dataset[i - 1].date,
d1 = dataset[i].date,
c = x0 - d0 > d1 - x0 ? [d1, i] : [d0, i - 1];
circles.attr('transform', 'translate(' +
x_main(c[0]) + ',' +
y_main(function (d) {return d.values[c[1]].value;}) + ')'
);
== EDIT ==
Working jsFiddle

You're passing in a function definition into your y_main scale:
circles.attr('transform', 'translate(' +
x_main(c[0]) + ',' +
y_main(function (d) {return d.values[c[1]].value;}) + ')'
);
selection.attr can take a string value or a callback function but this is trying mixing both of those. You're passing in a string and as the string is constructed it tries to scale the function itself as a value, which will return NaN.
The function version should look like this (returning the entire transform value):
circles.attr('transform', function(d) {
return 'translate(' +
x_main(c[0]) + ',' +
y_main(d.values[c[1]].value) + ')';
});

How can I efficiently convert data from string to int within a d3 method chain?

I'm making an interactive bar chart in d3, and have come across a problem. The bar chart reads data from a form, but it reads the data as a string. When I am using the data to draw bars like this:
var bars = svg.selectAll("rect")
.data(dataset)
.enter()
.append("rect")
.attr("x", function(d,i) {
return i * (w / dataset.length);
})
.attr("y", function(d) {
return h - (d * 4);
})
.attr("width", w / dataset.length - barPadding)
.attr("height", function(d) {
return d * 4;
})
.attr("fill", function(d) {
return "rgb(" + (d * redLevel) + ", 0, " + (d * blueLevel) + ")";
});
the data is read as a string. I could use parseInt(d) every time I wanted to use d, but that would be grossly inefficient. It would be easy to do var d = parseInt(d) outside of the method chain, but that wouldn't work with d3. Suggestions?

You could map the data before you bind it:
.data(dataset.map(function(d) { return +d; }))
Then unary + operator converts a numeric string into a number.