Read me


Some images are really bad on the web, but you can download the image and scale after on your computer.

Loading and saving

All the trees of a field can be loaded in one session in EVAT. Thus two subtrees can be simultaneously viewed. After analysis, the whole (created subtrees and trees) can be saved under EVAT in the gz Tulip format for future use.


In EVAT, there are three types of attributes.

Filtering and Extraction

Evat allows the user to filter on all attributes except the coordinates one. The filtering can be relative or not. It allows the composition by "and", "or" and "not" operators. It can be done directly by evat or using the advanced options. In any case, all the comparison operators act on string or numeric values.
If two trees are displayed within EVAT, then the same filter is applied to the two trees. The selected nodes then appears outlined in pink. After a selection is done, the user can, extract an induced structure (selected nodes and edges whose extremities are selected). This new structure is not necessarily a tree. The user can also extract the minimal covering subtree. In any case, the user is asked for a name and the new structure become a new tree in EVAT session.

Using size and color

Evat automatically draws trees using several algorithms : Then attributes can be mapped to the graphical attributes size and color. Two mapping exist uniform and linear. The user can also directly act (for example scaling) on these attributes using the manual option.


EVAT can be extended easily within its design. It means that drawings, comparison algorithms, navigation tools running under Tulip can be imported into EVAT.