[GRASS-user] Converting raster to polygon creates too many polygons

2010-09-29 Thread Hanlie Pretorius
Hi, I've created subcatchments using r.watershed and I would like to convert these to polygons. My result at the moment contains too many polygons - 194. The original raster had only 9 areas, which should all have been contiguous seeing that they came from r.watershed. Here is the sequence of

Re: [GRASS-user] Converting raster to polygon creates too many polygons

2010-09-29 Thread razmjooeis
You might consider using -s flag to smooth the corners. Otherwise, I can't see why it doesn't work. R. Sab Hi, I've created subcatchments using r.watershed and I would like to convert these to polygons. My result at the moment contains too many polygons - 194. The original raster had only 9

Re: [GRASS-user] Converting raster to polygon creates too many polygons

2010-09-29 Thread Micha Silver
On 09/29/2010 02:11 PM, Hanlie Pretorius wrote: Hi, I've created subcatchments using r.watershed and I would like to convert these to polygons. My result at the moment contains too many polygons - 194. The original raster had only 9 areas, which should all have been contiguous seeing that they

Re: [GRASS-user] Converting raster to polygon creates too many polygons

2010-09-29 Thread Markus Metz
Hanlie Pretoriuswrote: Hi, I've created subcatchments using r.watershed and I would like to convert these to polygons. My result at the moment contains too many polygons - 194. The original raster had only 9 areas, which should all have been contiguous seeing that they came from r.watershed.

Re: [GRASS-user] Converting raster to polygon creates too many polygons

2010-09-29 Thread Hanlie Pretorius
2010/9/29, Markus Metz markus.metz.gisw...@googlemail.com: In GRASS, you have full control of the computational region, consequently you must be able to explain (to the client/supervisor) every aspect of the computational region. Why is the horizontal resolution not only slightly off from

Re: [GRASS-user] Converting raster to polygon creates too many polygons

2010-09-29 Thread Markus Metz
Hanlie Pretorius wrote: I don't really know why the resolution in the x and y directions are not the same. Even when I set them explicitly, I get a slight difference: The -a flag is missing, see my previous post. - g.region -p vect=c83a_bor...@permanent nsres=25 ewres=25 projection: 99

[GRASS-user] First time GRASS user -- how to import an img dataset?

2010-09-29 Thread Mario Julio Barragan Arce
Hello. I need to learn how to use GIS and I have chosen to do it with GRASS. My plan is to learn GIS/GRASS essentials during the next 12 months and start applying it for my research the 12 months after that. I have started reading the documentation available and playing with the sample data set.

[GRASS-user] Open Streep Map

2010-09-29 Thread Mohammed Rashad
How to use openstreetmap data in GRASS GIS. In QGIS I have OSM plugin which allows to download, modify and upload of data. data can be editted offline and save changes back to OSM server. How to do these operation using GRASS GIS. sorry for cross posting -- Rashad

[GRASS-user] Any GRASS users in Puerto Rico?

2010-09-29 Thread Mario Julio Barragan Arce
Hello. I need to learn how to use GIS and I have chosen to do it with GRASS. My plan is to learn GIS/GRASS essentials during the next 12 months and start applying it for my research the 12 months after that. I started reading the available documentation and also started playing with the sample

Re: [GRASS-user] First time GRASS user -- how to import an img dataset?

2010-09-29 Thread Micha Silver
On 09/29/2010 06:12 PM, Mario Julio Barragan Arce wrote: Hello. I need to learn how to use GIS and I have chosen to do it with GRASS. My plan is to learn GIS/GRASS essentials during the next 12 months and start applying it for my Welcome, and good decision. research the 12 months after that.

[GRASS-user] Multiple arguments in a grass.command- Python

2010-09-29 Thread Luis Lisboa
Greetings I have a script where I need to define a region based on 2 rasters output[0] and output[1]. I'm using thwe following expression: grass.run_command(g.region, rast = output[2] output[3], res= t_srx) But This is not correct. my question is how can I have both rasters without getting an

Re: [GRASS-user] Any GRASS users in Puerto Rico?

2010-09-29 Thread Markus Neteler
On Wed, Sep 29, 2010 at 6:20 PM, Mario Julio Barragan Arce mariojulio.barra...@upr.edu wrote: Hello. I need to learn how to use GIS and I have chosen to do it with GRASS. Welcome here! My plan is to learn GIS/GRASS essentials during the next 12 months and start applying it for my research the

Re: [GRASS-user] Multiple arguments in a grass.command- Python

2010-09-29 Thread Glynn Clements
Luis Lisboa wrote: I have a script where I need to define a region based on 2 rasters output[0] and output[1]. I'm using thwe following expression: grass.run_command(g.region, rast = output[2] output[3], res= t_srx) But This is not correct. my question is how can I have both rasters

[GRASS-user] MDOW relief shading in GRASS

2010-09-29 Thread maning sambale
Hi, I am revisiting a previous script I made in producing Multidirectional, oblique-weighted, shaded-relief. ArcGis has this script: http://blogs.esri.com/Support/blogs/mappingcenter/archive/2008/10/07/updated-hillshade-toolbox.aspx The commads in ARC 6.0.1 GRID by Rober Mark (USGS) are as