1
vote
3answers
177 views

geography, geometry, distance, and wkt - PostGIS

I'm trying to understand the data conversions that happen in PostGIS when calculating distances in SRID 4326. Why is it that when I run on my marin_jobs points table: select cast (the_geom as ...
0
votes
0answers
94 views

Using Terraformer to convert to WKT

I'm using Terraformer to parse some ArcGIS JSON into a Terraformer primitive. I'd like to store the geometry in PostGIS for other purposes. So I'm trying to use the WKT.convert tool to convert this ...
0
votes
2answers
342 views

Converting WKT to WKB

How can I convert a WKT string to a WKB byte[] in Java using postgis functions? I need to save that WKT string in a postgis database (geometry column. Thanks
2
votes
2answers
384 views

Iterating polygons on a SpatialPolygonsDataFrame in R with readWKT

I have fetched some data (39 objects) from my PostGIS database and converted this data into a matrix: rs <- dbSendQuery(con, "SELECT ST_AsText(polygon_accumulation) AS ShapeWKT from ...
3
votes
0answers
110 views

PostGis functions vs. EWKT [duplicate]

While using PostGis, we can query using EWKT format like: SRID=4326;POINT(lon lat) or use the functions defined by PostGis itself. For example: ST_SetSRID( ST_MakePoint( lon , lat ) , 4326 ) I'm ...
3
votes
2answers
2k views

Is there any efficient way to convert Geojson to WKT?

I want to use ST_GeomFromText() to load vector data to PostGIS. However, I don't know how to convert from Geojson type to WKT. N.B. I know I can use OGR2OGR to upload the geojson directly, but I just ...
0
votes
2answers
183 views

How can I find the SRID from the WKT out of a GRIB file?

I have a grib2 file which I'm trying to import into PostGIS 2.0 Raster and process. Trouble is, I can't figure out what the SRID is supposed to be, or one close enough for government work. Running ...
3
votes
4answers
658 views

converting oracle geometry to postgis with 3d data (wkt?)

I am converting Oracle spatial database to postgis. Most of of the spatial data is 2.5d. Meaning we have a Z-coordinate which indicates the depth/height of the element compared to soil level. Getting ...
1
vote
1answer
153 views

How can I Transfer mysql wkt directly into a postgis table?

I have wkt geometry data in mysql stored in blob format. I need to get this data into a postgis db and am looking for the quickest-easiest way to do it. I have managed to select the data "ASTEXT" but ...
1
vote
1answer
187 views

What are AGF Files, how do we put them in PostGIS?

I came across term which says AGF, after Googling I found its Autodesk Geo Files, But some other say, Atlas Geo Files, Which one of them is right. I also came to know that It is an extension to WKT ...
7
votes
1answer
1k views

Help with PostGIS polygon geometry - non-closed rings

I've picked up a copy of the super-wicked book 'Python Geospatial Development' by Erik Westra (Amazon link), and I'm working through it. Currently, it's teaching me to load GSHHS coastline data from a ...