D3Trees

Flexible interactive visualization for large trees using D3.js.

Installation

Pkg.add("D3Trees")

Basic Usage

There are two ways to create a D3Tree object described below:

1) With AbstractTrees

Any object that implements the interface from AbstractTrees can be given to the constructor: D3Tree(object).

See the docstring (julia> ?D3Tree) for information on how to control the style.

2) Without AbstractTrees

The structure of a D3Tree is specified with lists of children for each node stored in a Vector of Int Vectors. For example,

D3Tree([[2,3], [], [4], []])

creates a tree with four nodes. Nodes 2 and 3 are children of node 1, and node 4 is the only child of node 3. Nodes 2 and 4 are childless.

Displaying Trees

In an IJulia notebook, the tree will automatically be displayed using D3.js. To get an interactive display in a chrome browser from the repl or a script, you can use the inchrome function. The blink function can also open it in a standalone window using the Blink.jl package.

children = [[2,3], [4,5], [6,7], [8,9], [1], [], [], [], []]
t = D3Tree(children)

inchrome(t)
inbrowser(t, "firefox")

By clicking on the nodes, you can expand it to look like the image at the top of the page.

Style Control

Optional arguments control other aspects of the style (use julia> ?D3Tree for a complete list), for example,

children = [[2,3], [], [4], []]
text = ["one\n(second line)", "2", "III", "four"]
style = ["", "fill:red", "r:14px", "opacity:0.7"]
link_style = ["", "stroke:blue", "", "stroke-width:10px"]
tooltip = ["pops", "up", "on", "hover"]
t = D3Tree(children,
           text=text,
           style=style,
           tooltip=tooltip,
           link_style=link_style,
           title="My Tree",
           init_expand=10)

inchrome(t)

will yield

or, see examples/hello.ipynb

Lazy loading trees

Deep trees can be expanded on demand from the visualization by clicking on unexpanded nodes. For example, see examples/LazyLoadDeepTrees.ipynb

The lazy loading can be controlled through two main keyword arguments:

• lazy_expand_after_depth which controls the initial expansion depth of the tree, before being sent as json to the visualization,
• lazy_subtree_depth which determines the depth of on-demand expanded subtrees.

# very deep tree
ldroot = LimitedDepthTree()
# launches visualization and click some nodes
D3Tree(ldroot, lazy_expand_after_depth=0,  lazy_subtree_depth=1)

returns

Text output

D3Trees also supports basic text output. This can be achieved by writing to an io object with the text/plain mime. This format is the automatic output if a D3Tree is created in the REPL:

julia> children = [[2,3], [4,5], [6,7], [8,9], [1], [], [], [], []];

julia> t = D3Tree(children)
1
├──2
│  ├──4
│  │  ├──8 (0 children)
│  │  └──9 (0 children)
│  └──5
│     └──1 (2 children)
└──3
   ├──6
   └──7

Browser compatibility

This package works best in the Google chrome or chromium browser.

Limitations

• This will not work offline because it downloads the D3 library on the fly (#10)