KerGIS has changed, but its website not yet.
The present informations are relative to an older state and are obsolete. Topology is still and even more than ever here. But almost the whole vectorial engine has been rewritten, and the presentation and the access to the data (1D: CLI, or 2D: GUI) are now clearly separated from processing of the data---at least for vectorial the modifications are achieved.
For die-hard like myself [Thierry Laronde], first come the work and the results, and second the advertisement. I'm perhaps old-fashioned. But I have the feeling that if I am, the new KerGIS is not, and by far...
While still waiting to update the web site, here is an example of
an application generated by GiG, the Graphical interface Generation,
allowing a "graphical" access, on a terminal, to KerGIS processing
commands on a CPU (a node doing the heavy stuff), and an example of what
can be generated for hardcopies, with automated layout, by combining
Adobe's PostScript(R), John D. hobby's MetaPost, and
Donald E. Knuth's TeX:
click to enlarge.
click to enlarge.
A CPU (in the Bell Labs Plan 9 terminology) does the processing, but does not handle user interfaces.
A terminal handles user interface, does not need a FPU (2D programs are purely arithmetic, i.e. integer based) and does no processing of actual data.
The KerGIS revolution has started...
What Is KerGIS?
KerGIS is a topological Geometrical Information System derived from the last public domain sources of G.R.A.S.S.® (Geographical Resources Analysis Support System) as published by the U.S. Army C.E.R.L. (Construction Engineering Research Laboratory).
KerGIS is not in the public domain and is released under the KerGIS Public Licence, which is a BSD like licence.
KerGIS is a System that is a coherent set of programs meant to work together in the same environment, used to add value to geometrical descriptions, whether by deducing topological or logical properties from the geometrical descriptions, or by adding non geometrical attributes to geometrical data (these attributes being stored in some king of database).
The system accepts and treats geometrical data in 3 main flavors:
- data description acquired by rasterizing (erudition): no rules are known but only a succession of ponctual facts describing exhaustively a given region (some values may be nul). Since, mathematically, there may be an infinite (more precisely: indefinite) number of points lying in a two dimensions region, the single values are not points but represent a definite rectangular area with fixed and constant width and height called a CELL. The main utilities of KerGIS will take these raw facts and deduce logical relationship, for example watershed etc. Raster data is by nature an approximation, but with a definite precision;
- an exhaustive description of the space in interest given by arcs that are oriented sets of vertices (vectorial): the vector is an exhaustive description of a finite number of arcs with almost infinite precision;
- a discret description of a region, by the gift of a finite set of singularities (sites) that may be, whether singular sites of interest, or an approximation of some aspect of a whole region by the gift of a finite number of weighted singularities. Sites are used as themselves, or as a transformation description.
Geometrical versus Geographical
There is nothing that prevents KerGIS (or the original GRASS) from being used for geometrical elements not directly representing a portion of the earth. KerGIS can be used for example with buildings plans.
Since geographical elements are specialized geometrical elements, involving mainly---for KerGIS---projection and datum, KerGIS is also---and at the moment mainly---a Geographical Information System. But the qualification geographical is misleading in the sense that it is not only usable with georeferenced data. Furthermore, when talking about projections, geographic may conflict with geodesic.
The Name Of The Game
KerGIS is aimed to be a GIS kernel, that is to provide a complete set of efficient core primitives (geometrical system calls) upon which one can build a dedicated application matching exactly a specialized GIS need. But as for a BSD system, this kernel will be provided with an environment (userland tools including a GUI) making KerGIS a self-contained generic GIS system, that can be customized.
Open Core
The public version of KerGIS is the core libraries and essential userland tools upon which one can build his/her customized version (Polynum develops its own version of which some aspects may be, at a given time, put in the public version; the amount of contributions from outside Polynum will drive the amount of Polynum's contributions, Polynum being, as of today, the sole contributor to the development).
The open source process is dedicated to the maintainance and development of the kernel. Its aim is to be the leaven, that is to allow gifted and ambitious developers to work starting from a huge existing code base presenting research and development opportunities in almost all the cutting edges of computer programming. KerGIS is one of Polynum's contribution to research, and this contribution is fully supported on private funds.
The provision of derived computer services (by subscription), professional support, extensions, training and customized development is the object of the commercial process.