A node-link structure is displayed within a display area having a narrow
rectangular shape with an edge along one side acting as a horizon of a
hyperbolic space half-plane. Lower level node features that share a
parent node feature have centers of area positioned on the display in
order along a line parallel with the horizon, with sufficiently similar
spacings along an axis perpendicular to the horizon from the region
around a parent node feature, and with sufficiently similar spacings in a
dimension parallel to the horizon from adjacent node features along the
line, that the lower level node features sharing the parent node feature
are perceptible as a group of related node features. The half-plane model
with compression is used for layout of the node-link data, and the
hyperbolic layout data is mapped to a Euclidean space for display.