Simon,
You might want to look at PostGIS. It is a GIS extension to the
posgresql database. There are windows installers for it. There is a
shapefile loaded and dumper, so you can easily load a shapefiles into
tables then do SQL queries with geospatial function. The postgis support
list has a bunch of very sharp people that can help you get started
doing the queries that you need to generate you results.
-Steve W
Simon Cropper (Botanicus Australia Pty Ltd) wrote:
Hi Everyone,
My name is Simon and I am an environmental consultant. I use a variety
of open source GIS systems and tools almost every day to analyse flora,
fauna and vegetation data. I am interested in OSGeo both from the
standpoint (or my underlying belief) that software and data should be
free (you know how the mantra goes) and my desire to contribute to a
broader community effort to develop appropriate software for users. I
have been actively using OpenJUMP, Kosmo, OpenEV, EveryDWG and Sextante.
I have tinkered with Ilwis, GRASS, Quantum (various versions) and a few
others I have lost track of. I am currently using GVSIG+Sextante, which
I find very useful and easy to use. I am an old user of ArcView
3.1+(numerous scripts/extensions).
I have a common GIS problem but can not find any OSGeo project that has
provided a set of tools to combat it. I need to establish the
distance+angle between various geometries (points, lines, polygons) in
same layer and in different layers. A specific problem I currently have
is finding the minimum distance and angle between 200 odd polygons in
the same layer. Each polygon has a unique id and I want to get a table
with UID_A, UID_B, MINIMUM_DISTANCE, ANGLE. I know that ArcGIS and
ArcView have this functionality, and script exist for old versions of
ArcView, but I am looking for an Open Source alternative.
Ideally such a tool would create the following data for each geometry
type...
POINTS -- UID_A, UID_B, DISTANCE, ANGLE
LINES -- UID_A, UID_B, DISTANCE_AT_CLOSEST _POINT
POLYGON -- UID_A, UID_B, MIN_DISTANCE, MAX_DISTANCE,
HAUSDORFF_DISTANCE, CENTROID_DISTANCE, ANGLE_BETWEEN_CENTROIDS
What I have found already...
* I have noted that Sextante can create a matrix of distances
between points within the same layer. With rows and column
representing the complete set of points being compared.
* I have also found QGIS has a fTools Plugin that allows you to
"Measure distances between two point layers, and output results as
a) Square distance matrix, b) Linear distance matrix, or c)
Summary of distances." QGIS 2009.
* I suspect that GRASS would provide this functionality but can't
get that package to work on my system (even WinGRASS), so if you
point me here please also point me to a tutorial on getting the
thing to work (this system is not intuitive; My problem has been
in establishing a repository and getting data into it for viewing,
let alone analysis; it failed the age old test that if you can't
even get the thing running in half an hour, the learning curve is
going to be way too high to use in in normal business activities;
I have tried - yes following their instructions - several times,
and spent several days reading manuals, wiki's,etc to no avail).
BUT I can't find any tool that allows me to calculate the minimum
distance between polygons and indicate the direction of the polygon.
Anyone out there know of such a tool?
Note: I am using Windows XP Pro SP3 and store all my GIS data as shapefiles.
--
Cheers Simon
Simon Cropper
Botanicus Australia Pty Ltd
PO Box 160, Sunshine, Victoria 3020.
P: 9311 5822. M: 041 830 3437.
mailto: [email protected]
<mailto:[email protected]>
web: www.botanicusaustralia.com.au <http://www.botanicusaustralia.com.au>
------------------------------------------------------------------------
_______________________________________________
Discuss mailing list
[email protected]
http://lists.osgeo.org/mailman/listinfo/discuss
_______________________________________________
Discuss mailing list
[email protected]
http://lists.osgeo.org/mailman/listinfo/discuss
