Abstract:
In explorative data analysis, the data under consideration often resides in a
high-dimensional (HD) data space. Currently many methods are available to
analyze this type of data. So far, proposed automatic approaches include
dimensionality reduction and cluster analysis, whereby visual-interactive
methods aim to provide effective visual mappings to show, relate, and
navigate HD data. Furthermore, almost all of these methods conduct the
analysis from a singular perspective, meaning that they consider the data in
either the original HD data space, or a reduced version thereof.
Additionally, HD data spaces often consist of combined features that measure
different properties, in which case the particular relationships between the
various properties may not be clear to the analysts a priori since it can
only be revealed if appropriate feature combinations (subspaces) of the data
are taken into consideration. Considering just a single subspace is, however,
often not sufficient since different subspaces may show complementary,
conjointly, or contradicting relations between data items. Useful information
may consequently remain embedded in sets of subspaces of a given HD input
data space. Relying on the notion of subspaces, we propose a novel method for
the visual analysis of HD data in which we employ an interestingness-guided
subspace search algorithm to detect a candidate set of subspaces. Based on
appropriately defined subspace similarity functions, we visualize the
subspaces and provide navigation facilities to interactively explore large
sets of subspaces. Our approach allows users to effectively compare and
relate subspaces with respect to involved dimensions and clusters of objects.
We apply our approach to synthetic and real data sets. We thereby demonstrate
its support for understanding HD data from different perspectives,
effectively yielding a more complete view on HD data.