[gdal-dev] Open source vector geoprocessing libraries?

[Jason Roberts]

> > Yes, I see what you mean. But I suggest to the open source community
> > that there is still value in implementing such features, either as
> > part of OGR or another library, even if optimal performance cannot be
> > guaranteed in all scenarios.
>
> Perhaps you'll find these inspiring:
>
> http://trac.osgeo.org/qgis/browser/trunk/qgis/src/analysis/vector

Thanks for the pointer. Yes those are inspiring, and also an example of what
prompted me to raise this topic in the beginning. Those are examples of how
QGIS implemented some basic geoprocessing with layers, e.g. intersect two
layers, symdiff two layers, and so on. My reason for raising the topic is
that each GIS has to reimplement those, and a lot of effort could be saved
if there were a common library of such functions. I was hoping such a
library already existed, and that I could draw from it (or even contribute
to it) for some spatial ecology tools that my team will be implementing,
with the goal of exposing these tools to multiple GIS programs, not just
ArcGIS as we currently do.

Many GIS projects support extensions. The authors realized the power of
contributions from the community. This can get very powerful when the
community converges on one program. For example, the R project has 2000
user-contributed packages. ArcGIS has thousands of user-contributed scripts
and tools. The open GIS community has many different GISes. This is a good
thing for various reasons, but it makes it hard for tool contributors to
reach lots of users: they must reimplement their tool for each different
GIS. If I pick QGIS then some users say "why not MapWindow"? Etc. It would
be great if there was a library, similar to the R CRAN project, that I could
contribute tools to without having to worry too much about all the
interoperability plumbing required to get the tool working with multiple
GISes. Perhaps I will try to start one. I'm already going to have to develop
that plumbing for my own project anyway.

Alternatively, is there one open source GIS that is accumulating all of the
market share, so to speak? If QGIS, for example, is becoming the most
popular then perhaps I could just pick it and ArcGIS, and not worry about
the others.

Anyway, thanks very much for your comments. They were very helpful.

Jason