About
What do we manipulate ?
The graph explorer is dedicated to browse multi-partite graphs (called G) that are projected into mono (e.g. graph terms or bipartite graphs (e.g. terms & scholars) :
- one or two components of the graph (called A and B), each formed of homogeneous types of nodes (e.g. terms and scholars)
- one or three types of links (e.g. A-A OR A-A/B-B/A-B)
- all links could be weighted,
- nodes can have attributes that can be overlayed on the graph (size and colors) or displayed in the right bar.
Quick description of language query (PDF slides) : GraphExplorer.pdf
Definitions/features
- types of nodes: For clarity, we will refer to type A and type B nodes in case of bipartite graphs. All nodes of the same type form a component of the graph. In the labelling of the button and legend, A and B will be replaced by the names of each component of the graph (e.g. 'terms' and 'scholars').
- selection : nodes that are selected by the search bar or mouse click. Selection has a radius from 0 (unique node selection) to some positive value so that we have a selection circle. The behaviour is : everything that is under the selection circle changes it's statutes : selected nodes are unselected and vice-versa. All nodes outside the selection circle are unselected unless the 'multiple selection' tick button is ticked.
- neighbors : the neighbors of a node are the nodes that link to it. In case of bipartite graphs, this could be ambiguous since there are two kinds of links : intra-component and inter-component. In case of bipartite graphs, the type of neighborhood required is given by the statute of the 'neighbors type' toggle button (former change type button). If you are in A state you see the whole A component, etc. This button is only visible in case of bipartite graphs
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Global/local view : the view can be in two states. The button of the tool bar are the same in the two states but their effects are different. You switch from global to local view with the "change view" buton (former "change level").
- Global view : this is when we see all the nodes of one of the components of the graph (all the As or all the Bs). In the global view, we never show different nodes types, it is always only all the As or all the Bs. You switch from one component to the other with the "change type" button. By default, at loading, we display the global view with type A nodes. Effect of switching component: when some nodes are selected and you switch the view, the new selection in the other component of the bipartite neighbors of this selected nodes.
- Local view : When you select some nodes in the global view, you can decide to see only your selection (e.g. a set of nodes A) and their closest neighbors (that could be of A or B types). Local view does this. When you switch to local view, you are either in the A or B "neighbor type" status. So you see you selection with the same type neighbors. In case of bipartite graphs, you can have heterogeneous networks if for example, you select some A nodes in the global view, change view and then and chose the display their component B neighbors by toogling the "neighbors type" button.
- Node Size : default node size is the log of the weight. But some nodes attributes can be mapped on the size if present in the nodes metadata. This can be changed in the colors dropdown button,
- Node color : by default, nodes are colored by their cluster component. But other colors can be mapped if other attributes are given. This can be changed in the color dropdown button.
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Filter : action on the button and sliders can hide some nodes or edges. The main filter are :
- Filter the edges : either removing weakest links or stronger links or both. Some nodes will become without neighbors.
- filter nodes : removing the weakest or strongest nodes according to the attribute chosen for the size
- Clustering nodes are clustered according to a default clustering algorithm (Louvain to start with). Cluster attribute is available in the color drodown button. Each time it is chosen there, the graph is clustered again taking into accound the filters.
- add button By default, when you select some nodes, it unselect the old selection. The 'add' button make it possible to cumulatively select elements from the graph.
Behaviour specific to the local view
In the local view, if you double click on a node, this makes it the new selection and their neighbors are displayed according to the statute of the neighbor type button.
Spatialization
- graphs are spatialized with the forceAtlas algorighm. It is usually in pause mode unless :
- at start : launching a spatialisation function that last for a time that depends on the graph. The time is given by T(G) (let's start with T(G)=2*#edges of G),
- when you click on the spatialize button.
Important remark : when you switch from global to local view, you keep the nodes positions in the filtered graph. But if you launch a spatialization in the local view, then you get temporary new positions. If you come back to the global view, you should come back to the permanent positions that can be changed only if you run a spatialization in the global view mode.
Top tool bar
Search
This field search among the labels of the nodes of the visible graph
Left area
The left area here is different from the tree view (left bar). Is is a space overlayed on the graph area. It will be implemented later but it will displays things such as :
- an automatic legend
- a minigraph of the evolution of the selected nodes frequency in the corpora
Tree view
The classic tree view is enriched with the following button
- take snapshot : png snapshot of the graph
- export graph : export the graph in JSON of Gexf