Sébastien Lafon

Learn More
In this paper, a new visual and interactive user interface for OLAP is presented, and its strengths and weaknesses examined. A survey on 3D interfaces for OLAP is detailed, which shows that only one interface that uses Virtual Reality has been proposed. Then we present our approach: it consists of a 3D representation of OLAP cubes where many OLAP operators(More)
The first step in digital signal processing is analog-to-digital conversion. Classically, the analog signal is sampled via the process described by the Whittaker-Kotelnikov-Shannon theorem (WKS), which requires that the original signal is band-limited. Irregular signals, as are fractal ones, typically do not verify such an assumption. The low-pass filtering(More)
We study in this paper the use of a 3D interface for OLAP. We analyze the state of the art in OLAP 3D visualizations. In a first step, we propose a new interface, called VR4OLAP, that combines the relative advantages of the studied methods. VR4OLAP can visualize 3 dimensions of an OLAP data cube and up to two measures. It represents the OLAP operators in(More)
In this paper, we propose a new method for the visual reorganization of online analytical processing (OLAP) cubes that aims at improving their visualization. Our method addresses dimensions with hierarchically organized members. It uses a genetic algorithm that reorganizes k-ary trees. Genetic operators perform permutations of subtrees to optimize a visual(More)
  • 1