[gdal-dev] Re: Countour polygons instead of lines

Hello! Although your message is already some days old I wanna respond. Did you ever want gdal_contour to produce polygons instead of lines? Yes! I made a small Perl program that uses the Perl bindings to GDAL and which converts the lines into polygons. The polygons represent "plates" of equ

Re: [gdal-dev] Datum transformation method when projecting from a sphere to NAD83 shapefile

Limei Ran wrote: Hi Frank: You mentioned that I have not provided a datum definition for the source coordinate system, only an ellipsoid definition. Could you tell me how I can provide the datum definition to get the same result from PROJ4.5? The command I used is: ogr2ogr -t_srs "+proj=a

Re: [gdal-dev] Datum transformation method when projecting from a sphere to NAD83 shapefile

If your projections have epsg codes, you might use those instead. E.g.: ogr2ogr -t_srs "EPSG:4326" -s_srs "EPSG:26911" outfile.shp infile.shp You can check for epsg codes (or their equivalent wkt, proj4, etc.) at http://spatialreference.org . Regards, John On Sep 9, 2008, at 10:46 AM, Limei R

Re: [gdal-dev] Datum transformation method when projecting from a sphere to NAD83 shapefile

Hi Frank: You mentioned that I have not provided a datum definition for the source coordinate system, only an ellipsoid definition. Could you tell me how I can provide the datum definition to get the same result from PROJ4.5? The command I used is: ogr2ogr -t_srs "+proj=aea +lat_1=29.5 +la

[gdal-dev] Out of Office

Vielen Dank für Ihre Nachricht. Ich bin bis einschließlich 26.09.2008 nicht im Büro und kann Ihre Anfrage leider nicht bearbeiten. Ihre Nachricht wird nicht automatisch weitergeleitet. Ich werde Ihre eMail gerne nach meiner Rückkehr beantworten. Thank you very much for your message. I'm out of

Re: [gdal-dev] negative buffer

Hi Bruce, Could you give a sense of what you want to cluster and what your objective is with respect to the use of the clustering results? There are a lot of clustering methods out there, so knowing a bit about what you want to accomplish would help. Dan On Tue, 2008-09-09 at 11:13 -0400, Clay,

Re: [gdal-dev] Datum transformation method when projecting from a sphere to NAD83 shapefile

Limei Ran wrote: Hi Frank: Thank you for your information. Is any reason that PROJ4.6. or newer does not do any datum transformation when going from LCC Sphere to NAD83 Albers? We are using many shapefiles generated in arcGIS, GDAL or by other tools. We want to have the consistent shapefile

[gdal-dev] negative buffer

I am trying to use GDAL to cluster a group of points. I am creating a buffer around the points then testing buffered points for intersection. I am putting those that intersect into a GeometryCollection then creating a convexHull to smooth the polygon. All of that works ok but the problem is th

Re: [gdal-dev] Datum transformation method when projecting from a sphere to NAD83 shapefile

Hi Frank: Thank you for your information. Is any reason that PROJ4.6. or newer does not do any datum transformation when going from LCC Sphere to NAD83 Albers? We are using many shapefiles generated in arcGIS, GDAL or by other tools. We want to have the consistent shapefiles. Could you tell

[gdal-dev] problem with ERDAS Imagine files in StatePlane projection

I am using GDAL with C# bindings from gdal_csharp.dll and reading the projection information from an ERDAS Imagine file in Stateplane Projection (EPSG 2263). GDAL doesn't seem to be able to parse the stateplane projection information in the Imagine file correctly when writing out as a GeoTIFF. My

Re: [gdal-dev] Datum transformation method when projecting from a sphere to NAD83 shapefile

Limei Ran wrote: Hi: I am using ogr2ogr to project a shapefile defined in a sphere to NAD83. My command is like the following: ogr2ogr -t_srs "+proj=aea +lat_1=29.5 +lat_2=45.5 +lat_0=23 +lon_0=-96 +x_0=0 +y_0=0 +ellps=GRS80 +datum=NAD83 +units=m +no_defs " -s_srs "+proj=lcc +a=637.0 +

[gdal-dev] Datum transformation method when projecting from a sphere to NAD83 shapefile

Hi: I am using ogr2ogr to project a shapefile defined in a sphere to NAD83. My command is like the following: ogr2ogr -t_srs "+proj=aea +lat_1=29.5 +lat_2=45.5 +lat_0=23 +lon_0=-96 +x_0=0 +y_0=0 +ellps=GRS80 +datum=NAD83 +units=m +no_defs " -s_srs "+proj=lcc +a=637.0 +b=637.0 +lat_1