Skip to content

Instantly share code, notes, and snippets.

Last active Nov 24, 2021
What would you like to do?
Moving xAxis along with line
(function() {
var n = 243,
duration = 750,
now = new Date( - duration),
count = 0,
data = d3.range(n).map(function() { return 0; });
var margin = {top: 6, right: 0, bottom: 20, left: 40},
width = 960 - margin.right,
height = 120 - - margin.bottom;
var x = d3.time.scale()
.domain([now - (n - 2) * duration, now - duration])
.range([0, width]);
var y = d3.scale.linear()
.range([height, 0]);
var line = d3.svg.line()
.x(function(d, i) { return x(now - (n - 1 - i) * duration); })
.y(function(d, i) { return y(d); });
var svg ="body").append("p").append("svg")
.attr("width", width + margin.left + margin.right)
.attr("height", height + + margin.bottom)
.style("margin-left", -margin.left + "px")
.attr("transform", "translate(" + margin.left + "," + + ")");
.attr("id", "clip")
.attr("width", width)
.attr("height", height);
var axis = svg.append("g")
.attr("class", "x axis")
.attr("transform", "translate(0," + height + ")")
.call(x.axis = d3.svg.axis().scale(x).orient("bottom"));
var path = svg.append("g")
.attr("clip-path", "url(#clip)")
.attr("class", "line");
var transition ={}).transition()
.on("scroll", function() { ++count; });
(function tick() {
transition = transition.each(function() {
// update the domains
now = new Date();
x.domain([now - (n - 2) * duration, now - duration]);
y.domain([0, d3.max(data)]);
// push the accumulated count onto the back, and reset the count
data.push(Math.min(30, count));
count = 0;
// redraw the line".line")
.attr("d", line)
.attr("transform", null);
// slide the x-axis left;
// slide the line left
.attr("transform", "translate(" + x(now - (n - 1) * duration) + ")");
// pop the old data point off the front
}).transition().each("start", tick);
Copy link

I forked the code pen from @Atticweb and updated to v4. Everything seems to be working properly, but I'm a little unhappy with the transition of the axis text, it doesn't respect the easing (jumpy), but the ticks transition smoothly. Any ideas?

I'm pretty new to d3, but wanted to use this same idea in a similar project that requires v4.

Copy link

Hey guys, thanks for the code.
I am trying to connect this to a webocket. I thought I'll start with random values coming through a timer:
setInterval(function(){ tick(); }, 500);
as a start . Instead of the method used in the example:

.transition().each("start", tick);

But I can't get to run smoothly: See:

Any idea what I am missing ? I've tried everything I could think of/find online.
Any help would be greatly appreciated !

Copy link

abitbetterthanyesterday commented Nov 24, 2021

For anyone out there wondering what the answer is about @daniel-cohen 's issue.

I think there is a default duration when using duration(), so your code 'updates' every X ms, hence the jumpy behaviour.

Simply replace your code by .transition().duration(1).each("start",tick) 🚀

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment