Is it possible to create d3 nodes with multiple edge ports? - javascript

I'd like to achieve something similar to this diagram using d3:
https://gojs.net/latest/samples/records.html
I was trying to look it up on the web but I hardly found any resources to get started with.
I'm quite new to d3 so I don't know how to approach this task, any help or guidance would be appreciated!

This is another one of those questions where people need to implement a sophisticated diagram visualization and they think just because D3 is a lot about visualization, it will be a good fit.
IMHO it is not.
D3 could be a part of the solution, but it certainly cannot be the solution alone: It's almost like asking whether JavaScript can be used to create this kind of diagram. Of course it can! D3 is just a very thin (but very useful) layer on top of the DOM+JavaScript, that can help you with crunching numbers, work with colors, coordinate systems, create DOM elements, and simplifies working with the DOM. Think of it as jquery for DOM and data plus a lot of very nice demos. But the value very often is in the demos, rather than in D3 itself: You need to implement a lot of things to get from a simple mapping from data to dom elements to a sophisticated diagram visualization like the one you are referring to.
If you don't want to implement and maintain most of the low-level diagram logic yourself, you should rather be looking at a diagramming solution, rather than a tool that will help you create SVG elements elegantly with less code.
Look at this question to see a list of graph and diagram visualization software. Agreed, D3 is also on this list (for the same reason you are asking this question), but there are also far more capable tools on that list that you should be looking at, my recommendation being either the one that you've found already or preferrably this one if your requirements are more sophisticated.

Related

Javascript big-data visualisation

I'm about to develop a UI for medical research application. I need to make a time series line graph. Main issue is the amount of data:
5,000 points per graph, with a few of them displayed simultaneity. I’m expecting 50,000 points processed all together.
The question is what presentation library?
The main features I’m looking for are: Handles huge data sets, Zoom, annotations, live update.
I’m already looking into http://dygraphs.com/ and http://meteorcharts.com/
I wouldn't want any library that renders the data as DOM elements, or that uses SVG (from performance perspective)
Well, I think I'll give everyone my own answer to my question:
Dygraphs (http://dygraphs.com/) seems to be on the spot. The documentation, although a lot of apparent efforts, leaves a lot to be desired. But from performance, features and flexibility, it's the best I've seen. At least for my current project needs.
Way to go, Dygraphs!
Have you checked out D3? I'm using that for a lot of graph visualization. It looks like this example renders to svg.
My stuff renders to a SVG for force graph visualizations too, but it looks like D3 might be able to use either a canvas or SVG, but I'm not positive about what all can be rendered to which. Honestly, I'd give D3 a try even with SVG, it might be fast enough. I remember reading something about someone simulating thousands of particles using D3's force graph visualizations without issues. It's SUPER easy to get your data into the right format for it to use.
Good luck!
I am developing a very similar application.
I am currently using Flot for the chart rendering. It handles annotations and zoom, take a look at their plugin library.
I recommend this downsampling plugin which will speed up graph rendering. Rendering 5000 points on your graph is useless: you have less vertical pixels on your screen than that! so this library will only render those that actually have a visual importance.
This only gives you the graph. You may want some kind of dashboard to present all that... I am currently looking at Grafana, which is used for a totally different purpose but makes awesome dashboards. It may be possible to "rip out" their dashboarding features (it uses Flot as well).
Another option is Hightcharts, but that's not free.
Check raphael js Library
Raphaël is a small JavaScript library that should simplify your work with vector graphics on the web. If you want to create your own specific chart or image crop and rotate widget, for example, you can achieve it simply and easily with this library.

What is the difference between D3 and jQuery?

Referring to this example:
http://vallandingham.me/stepper_steps.html
it seems that the D3 and jQuery libraries are very similar in the sense that they both do DOM manipulation in an object-chaining way.
I'm curious as to know what functions D3 makes easier than jQuery and vice versa. There are plenty of graphing and visualization libraries that use jQuery as a basis (e.g., highcharts, flot, wijmo).
Please give specific examples of how they are different.
D3 is data-driven but jQuery is not: with jQuery you directly manipulate elements, but with D3 you provide data and callbacks through D3's unique data(), enter() and exit() methods and D3 manipulates elements.
D3 is usually used for data visualization but jQuery is used for creating web apps. D3 has many data visualization extensions and jQuery has many web app plugins.
Both are JavaScript DOM manipulation libraries, have CSS selectors and fluent API and are based on web standards which makes them look similar.
Following code is an example of D3 usage which is not possible with jQuery (try it in jsfiddle):
// create selection
var selection = d3.select('body').selectAll('div');
// create binding between selection and data
var binding = selection.data([50, 100, 150]);
// update existing nodes
binding
.style('width', function(d) { return d + 'px'; });
// create nodes for new data
binding.enter()
.append('div')
.style('width', function(d) { return d + 'px'; });
// remove nodes for discarded data
binding.exit()
.remove();
d3 has a silly description. jQuery and d3 are not at all similar, you just don't use them for the same things.
jQuery's purpose is to do general dom manipulation. It's a general purpose javascript toolkit for anything you might want to do.
d3 was primarily designed to make it easy to make shiny graphs with data. You should definitely use it (or something similar, or something built on top of it) if you want to make graphical visualizations of data.
If you want a general purpose JS library for all your interactive form needs, consider jQuery or proto or mootools. If you want something tiny, consider underscore.js. If you want something with dependency injection and testability, consider AngularJS.
A General comparison guide from wikipedia.
I can see why someone would think they are similar. They use a similar selector syntax -- $('SELECTOR'), and d3 is an extremely powerful tool for selecting, filtering, and operating on html elements, especially while chaining these operations together. d3 tries to explain this to you on its home page by claiming to be a general purpose library, but the fact is that most people use it when they want to make graphs. It is pretty unusual to use it for your average dom manipulation because the d3 learning curve is so steep. It is, however, a far more general tool than jQuery, and generally people build other more specific libraries (such as nvd3) on top of d3 rather than using it directly.
#JohnS's answer is also very good. Fluent API = method chaining. I also agree about where the plugins and extension lead you with the libraries.
I've been using a little of both lately. Since d3 uses Sizzle's selectors you can pretty much mix up selectors.
Just keep in mind d3.select('#mydiv') doesn't return quite the same as jQuery('#mydiv'). It's the same DOM element, but it's being instantiated with different constructors. For example, let's say you have the following element:
<div id="mydiv" rel="awesome div" data-hash="654687867asaj"/>
And let's grab some common methods:
> d3.select('#mydiv').attr('rel') ;
"awesome div"
> jQuery('#mydiv').attr('rel');
"awesome div"
Seems legit. But if you go a little further:
> d3.select('#mydiv').data();
[undefined]
> jQuery('#mydiv').data();
Object {hash: "654687867asaj"}
D3 is not just about visual graphs. Data Driven Documents. When you use d3, you bind data to dom nodes. Because of SVG we are able to make graphs, but D3 is so much more. You can replace frameworks like Backbone, Angular, and Ember with using D3.
Not sure who down voted, but let me add some more clarity.
Many websites request data from the server, which usually comes from a database. When the website receives this data, we have to do a page update of the new content. Many frameworks do this, and d3 does this as well. So instead of using a svg element, you can use html element instead. When you call the redraw, it'll quickly update the page with the new content. It's real nice to not have all the extra overhead like jquery, backbone + its plugins, angular, etc. You only need to know d3. Now d3 doesn't have a routing system baked into it. But you can always find one.
Jquery on the other hand, it's sole purpose is to write less code. It's just a short hand version of javascript that has been tested on many browsers. If you don't have a lot of jquery on your webpage. It's a great library to use. It's simple and takes a lotta pains out of javascript development for multiple browsers.
If you tried to implement jquery in a d3 like fashion, it'll be quite slow, as it wasn't designed for that task, likewise, d3 isn't design to post data to servers, it's designed just to consume and render data.
d3 is made for data visualization, it does this by filtering through DOM objects and applying transformations.
jQuery is made for DOM manipulation and making life easier for many basic JS tasks.
If you're looking to turn data into pretty, interactive pictures, D3 is awesome.
If you're looking to move, manipulate or otherwise modify your webpage, jQuery is your tool.
Great question!
While both libraries share many of the same features, it seems to me that the greatest difference between jQuery and D3 is the focus.
jQuery is a general purpose library with a focus on being cross-browser and being easy to use.
D3 is focused on data (manipulation and visualisation) and supports only modern browsers. And while it does look like jQuery, it's a lot more difficult to use.
Both can solve the same purpose of creating and manipulating a DOM (whether it be HTML or SVG). D3 surfaces an API that simplifies common tasks you would take when generating/manipulating a DOM based on data. It does this through it's native support for data binding via the data() function. In jQuery you would have to manually process the data and define how to bind to the data in order to generate a DOM. Because of this, your code becomes more procedural and harder to reason and follow. With D3, it's less steps/code and more declarative. D3 also provides some higher level functions that aid in generating data visualization in SVG. Functions like range(),domain(), and scale() make it easier to take data and plot them on a graph. Functions like axis() also make it easier to draw common UI elements you would expect in a chart/graph. There are many other higher-level api libraries that sit on top of D3 to aid in more complex visualizations of data including interactive behavior and animation.

Javascript Library to dynamically create graphs?

Here is my requirement:
I need to create a visualization of links between different representations of a person. The image below I think indicates that fairly clearly.
Additionally, those rectangles would also contain some data about that representation of a person (such as demographics and the place). I also need to be able to handle events when clicking on the boxes or the links between them, as a sort of management tool (so, for example, double clicking a link to delete it, or something along those lines). Just as importantly, since the number of people and links will varies, I need it to be displayed by spacing out the people in a roughly equidistant fashion like the image shows.
What would be a javascript library that could accomplish this? I have done some research and have yet not found something that can cleanly do this but I'm hardly an expert in those libraries.
Here are the ones I've looked at:
Arbor js: Can dynamically create the spacing and links of the graph but I'm responsible for rendering all the visuals and there's really no hooks for things like clicking the links.
jsPlumb: Easily create connections between elements and draws them nicely enough but doesn't seem to address any layout issues. Since I don't know how many people will be on the screen, I have to be able to space them out equidistant and that doesn't seem to be a concern of jsPlumb.
D3.js: This creates a good visualization with the spacing I need but I don't see how I can show the data inside each node or do things like like mouse events on the links or box.
I'm feeling a bit lost so I'm hoping someone could point me to something that could help me or maybe point me to an example from one of these libraries that shows me that what I want is possible.
I ended up using Arbor with Raphael as my rendering library and it's worked out very well.
Take a look at Dracula Graph Library. It's a simple library that seems to do both layout as well as rendering graphs (using Raphael under the hood). It's a bit underdeveloped however.

What is the best approach to producing graphical charts in a browser?

I've started a new open source project aimed at providing a quality project management experience. To do this, I need access to a set of chart tools (Flash is off the table), and very specifically one that includes a Gantt chart. I've done my homework and shopped around the web and I've more or less come to the conclusion that what I want doesn't exist, at least not for free. So chances are I'm going to have to write this from scratch.
If I was going to create a Gantt chart with which people could interact with (which I'm assuming means having excellent DOM support), then what technology would I use? Should I go with SVG? Or HTML5 Canvas? Something else? Your suggestions are much appreciated.
Also, a requirement would be that whatever library I use needs to be actively supported in the community (i.e. no dead projects).
I would not think there would be many free options as this is a niche-need.
JS Option:
http://www.jsgantt.com/
http://code.google.com/p/flot/
Promising Perl modules:
http://cpansearch.perl.org/src/DARNOLD/DBD-Chart-0.82/dbdchart.html
http://search.cpan.org/~awestholm/Project-Gantt-1.03/Gantt.pm
Update:
There's been amazing advancements in terms of interactive/web charts in the past few years. Shortly before your question was asked, D3.js was created, which has become a generally accepted library, which uses SVG to implement visualizations. Here's a basic example and a more advanced implementation using D3. Note; Gantt charting is still in its infancy; D3 will most likely revisit it in the future.
The argument of Canvas vs SVG is one that has been considered many times. You should read this article by Microsoft; How to Choose Between Canvas and SVG for your Site. Basically, if you have many elements you have to display, Canvas will perform much better. If accessibility is a priority, SVG is better.
In terms of working with Canvas vs SVG, canvas feels more fluid and it is certainly more capable with WebGL, but SVG is more transportable. They both have their merits.
If you're going to make your own, I'd recommend the SVG library Raphaël, which allows you to draw things using SVG fairly easily. It's also simple to make mouse event handlers and other things, which you could use to make it interactive.
I haven't had much experience creating interactive graphics with canvas, but my instinct is that it would be hard to handle mouse events since you don't have "elements" to add event listeners to.

Good Ajax Chart/Graphic Library

I know there has been several discussions on JavaScript chart/graphics libraries, and there is many out there. What I need is one that can:
Zooming and panning
Data point manipulation (like when click on a data point, highlight other data points within the data series with the same certain parameter of the clicked one)
Dynamically change data point values (e.g.: dragging a data point dynamically updating the line shape)
Error bar support, horizontally and vertically
Select data points on the chart
Seems like Flot may have most of the features, if not all(not sure about 3, and 4), but would like to see if I don't miss out on there nice libraries.
Check out the awesome Visualization API on Google's AJAX APIs Playground
Take a look at http://raphaeljs.com/ library.
It has a plugin called gRaphaël which is charting plugin.
Look good but personally didn't use it.
Good luck and share you expirience if you try it.
The Dojo Charting Engine has a pretty astonishing featureset. Sadly dojo seems to suffer from a general lack of evangelism.
I dont know if there are good introductory tuts, maybe the best way is to learn from examples.

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