GraphViewer is a web application for visualizing and interactive exploration of graph data. GraphViewer is a generalized version of the original SMC Browser. It is implemented on top of wonderful js-library d3, the code available on github. There is also some preliminary technical documentation.

User Interface

The user interface is divided into 4 main parts:

Lists all available Profiles, Components, Elements and used Data Categories The lists can be filtered (enter search pattern in the input box at the top of the index-pane). By clicking on individual items, they are added to the selected nodes and get rendered in the graph pane.
Main (Graph)
Pane for rendering the graph.
This is the control panel governing the rendering of the graph. See below for available Options.
In this pane, overall summary of the data is displayed by default, but mainly the detail information about the selected nodes is listed here.


Following data sets are distinguished with respect to the user interaction:

all data
the full graph with all profiles, components, elements and data categories and links between them.
selected nodes
nodes explicitely selected by the user (see below how to select nodes).
data to show

the subset of data that shall be displayed.

Starting from the selected nodes, connected nodes (and connecting edges) are determined based on the options (depth-before, depth-after).

The nodes are colour-coded by type:

the legend to the graph

There are multiple ways to select/unselect nodes:

select from index

by clicking individual items in the index list, the item will be added to the selected nodes

clicking on an already selected item unselects it

select in graph

by clicking on a visible node in the graph, the node will be added to the selected nodes

clicking on an already selected node unselects it

select area in graph
by dragging (hold mouse button down and pull) a rectangle in the graph pane, all nodes within that rectangle get selected all other nodes will be unselected
unselect in detail pane
clicking on an item in the detail pane unselects it
select in statistics
as mentioned in Data (some) numbers in the statistics reveal a list of corresponding terms. Clicking on these terms in the statistics page leads to the browser, with given term as selected node (and default settings)
select in statistics in the detail pane
the numbers from statistics page are shown also in the detail pane for selected nodes. Here, clicking on a term from these lists adds it to the graph, as a selected node.
on mouse over a node, all connected nodes to given node (and connecting links) within the visible sub-graph are highlighted and all other nodes and links are faded
drag a node
click and hold on a node, one can move the node around, however usually the layout is stronger and puts the node back to its original position. Not so with the freeze-layout, that freezes all the nodes and lets you move them around freely


The navigation pane provides the following options to control the rendering of the graph:

how many levels of connected ancestor nodes shall be displayed
how many levels of connected descendant nodes shall be displayed
approximate distance between individual nodes (not exact, because it is just one of multiple factor for the layouting of the graph)
the higher the charge, the more the nodes tend to drift apart
factor for "cooling down" the layout, lower numbers (50-70) stabilize the graph more quickly, but it may be too early, with higher numbers (95-100) the layout has more time/freedom to arrange, but may get jittery

N = all nodes have given diameter N;

usage = node is scaled based on how often the node appears in the complete dataset i.e. often reused elements (like description or language) will be bigger

show/hide all labels hiding the labels accelerates the rendering significantly, which may be an issue if more nodes are displayed. irrespective of this option, on mouseover labels for all and only the highlighted nodes are displayed
straight or arc (better visibility)

There are a few layouting algorithms provided. They are all not optimal in any way, but most of the time, they deliver quite good results. For different data displayed other algorithm may be more appropriate:

undirected layout, trying to spread the nodes in the pane optimally, equally in all directions This is the underlying layouting algorithm. All the other layouts build on top of it, by just adding further constraints.
top-down layout respect the direction of the edges, children are always below the parents
left-right layout respect the direction of the edges, children are always right to the parents (at least they should be, currently, in certain configurations, the layout does not get the orientation for some links right)
a layout that "tends" towards left to right arrangement, but not strictly so (experimental)
strict left to right reusing the x-positioning as determined by dot Arranges the nodes in strict ranks (typical for dot layout) This is done in a separate preprocessing step for the whole graph, so the positioning may be suboptimal for a given subgraph. The y-coordinate is approximated on the fly by the base algorithm.
this is actually a "no-layout" - the nodes just stay fixed in their last position, However, individual nodes still can be dragged around, so this can be used to adjust a few nodes for better legibility (or aesthetics), but only when you start moving around inividual nodes, you will learn to appreciate the great (and tedious) work of the layouting algorithms, so generally you want to try to play around with the other settings to achieve a satisfying result.

Linking, Export

The navigation pane exposes a link, that captures the exact current state of the interface (just the options and the selection, not the positioning of the elements), so that it can be bookmarked, emailed etc.

Furthermore, there is the download, that allows to export the current graph as SVG. This is accomplished without a round trip to the server, with a javascript trick serializing the svg as base64-data into the url (so you don't want to save (or see) the exported url). But you can both, right click the link and [Save link as...], or click on the link, which opens the SVG in a new tab where you can view, resize, print and save it. Employing this simple method also means, that there is no possibility to export the graph in PNG, PDF or any other format, because this would require server-side processing. (However this is a planned future enhancement.)


Chrome is by far the fastest, followed by IE(9). A serious performance degradation was observed for graphs above 200 nodes on Firefox. Showing labels also significantly affects performance.
When the graph gets to big, it does not fit in the viewing pane. This will be tackled soon (either scrollbars or applying boundaries). Meanwhile, you can reduce the link-distance and charge parameters or change the layout.

Plans and ToDos