(1) abstract geometry; (2) storing geographic data in projected coordinates; (3) a generic ESRI term for vector features; a class for "geometry" objects.

learn more… | top users | synonyms

1
vote
1answer
58 views

How do I convert OS coordinates (X and Y) to longitude and latitude coordinates?

How do I convert OS coordinates (X and Y) - Eastings and Northings to longitude and latitude coordinates? For example X and Y below X (Eastings): 347904 Y (Northings): 287484
1
vote
1answer
97 views

How do I figure out the grid references (Eastings and Northings) necessary to create a circular 1 mile radius around one location?

How do I figure out the grid references necessary to create a circular 1 mile radius around one location? For instance: Grid Reference: SO 47904 87484 X (Eastings): 347904 Y (Northings): 287484 ...
10
votes
3answers
13k views

How to convert .shp to .csv including attributes AND geometry?

I have a .shp file with 60k+ entries, all of which are polygons with corresponding attributes (acreage totals, landowner names, tax ID #s, etc.). What I ultimately need is a .csv file with all of ...
3
votes
1answer
134 views

How do I figure out the longitude and latitude coordinates necessary to create a circular 1 mile radius around one location?

How do I figure out the longitude and latitude coordinates necessary to create a circular 1 mile radius around one location? I don't mind how many coordinates that takes. For instance: Latitude = ...
0
votes
1answer
77 views

Get the vertices on a LineString either side of a point (Sql Server 2008)

I have a point that sits on top of a LineString, both Sql Geometry types. POINT('0.5 0.5') LINESTRING('0 0 NULL 1, 1 1 NULL 1') I want to find the vertices of the LineString that lie either side ...
1
vote
0answers
75 views

Using M 'Measure' value in SQL Server 2008

MS Sql Server 2008 geometry type supports adding Z and M values to geometry objects, including linestrings. However, I cannot find any way to make use of these values, since methods such as ...
32
votes
4answers
5k views

What are the pros and cons of PostGIS geography and geometry types?

My company uses geometry (the_geom) data type for storing geospatial data. I've recently been acquainted to the concept of geography (the_geog) data type which, as I understand it, stores the SRID ...
1
vote
2answers
3k views

How to initialize a WFS Layer?

Here is the code block (the layers are stored in Oracle database): var saveStrategy = new OpenLayers.Strategy.Save(); var adresspt_wfs = new OpenLayers.Layer.Vector("Address points WFS", ...
3
votes
1answer
152 views

Get geometry column back when counting points in polygon using PostGIS

I have two PostGIS tables: earthquakes and borders, which contain point data on earthquake locations, and polygons of countries in the world respectively. I want to try and count the earthquakes ...
1
vote
1answer
60 views

Adding geometry to rows with missing X,Y inArcGIS

I have a table with X, Y data that contains many rows with still missing coordinates. Now I would like to edit it in ArcGIS 10 and simply add the geometry for selected lines after identifying the ...
1
vote
1answer
234 views

Multipoint vs point PostGIS

Is it normal to use the geometry type 'multipoint' instead of 'point' knowing that I use it to store only one point. How can I convert from multipoint to point
3
votes
5answers
649 views

How to Identify and Delete duplicate vertices?

I am trying to figure out how to delete duplicate vertices. I have successfully determined that there are duplicate vertices using PLTS Data Reviewer, but I am confounded as to how I identify and ...
3
votes
1answer
490 views

Multiple geometry columns for points, lines, and polygons in spatialite?

I'm rather new to the GIS world and even newer to Spatialite and trying to create a new DB for our application. I would like to create spatial index(es) on the geometry column(s), but our geometry ...
5
votes
3answers
95 views

What is the PostGIS 2.x equivalent of the pre-PostGIS 1.5 ~= operator?

Stemming from my other question: When would a PostGIS geometry compare using ~= return true when ST_Equals returns false?, what is the PostGIS 2.x equivalent of the pre-PostGIS 1.5 ~= operator? It ...
2
votes
1answer
78 views

When would a PostGIS geometry compare using ~= return true when ST_Equals returns false?

I have a couple of featureclasses in a 10.2 geodatabase/PostgreSQL 9.2.2 database and I've been struggling with the FeatureCompare tool--it is telling me geometries are different on some features ...
1
vote
2answers
79 views

Problem - ST_AsGeoJSON return text with accolade

I am saving a result of ST_AsGeoJSON(..) into csv file. But the results I got can't be interrupted as an object later on. How can I polish and delete the accolades that I don't need. ...
2
votes
2answers
156 views

Is there Shape Metrics Toolbox or equivalent for ArcGIS 10?

I need to compute the geometric properties (e.g. contiguity index, dispersion index etc.) of a series of polygons and I would like to use the Shape Metrics Toolbox. I am using ArcGis 10 and the ...
1
vote
1answer
610 views

PostGIS Select Union of Polygons

I have a Postgres 8.4 PostGIS 2.0 enabled database and I've loaded it up with a bunch of shapefiles. I'm trying to get the database to do on-the-fly unions of geometries. Here is the query I'm ...
1
vote
2answers
174 views

Get the vertices on a LineString either side of a Point

I have a shapely LineString and defined a shapely Point which lies along the LineString. How can I find the vertices of the LineString which lie either side of the point? (split the line in two). ...
0
votes
0answers
21 views

Is there a way of converting polygon vertices to points using GDAL python? [duplicate]

I have an ArcGIS standard license and I want to convert polygon vertexes to points in a script. Since I don't have a good enough ArcGIS license I've been using ET Geowizards to get the points. The ...
2
votes
3answers
212 views

Fastest way to join points table to polygons tables in ORACLE

I have two tables in 11g oracle db, one with points geometry, one with polygons. Currently I need to enrich the points table daily with the name of the polygon (country) that the point is inside, but ...
5
votes
2answers
111 views

Can someone give the absolute lowdown on the following list of spatial operators

Ok, I have to admit, I don't really delve too deep into the semantics of the spatial operators list below, I'm more of a user, I write software to drive the SQL most of the time and don't really think ...
0
votes
0answers
70 views

Which geo-location available in Twitter data should I use?

I am extracting twitter location on my side.Few tweets has perfect location but in most cases additional details are available (i.e. Country,bounding_box,poly lines etc) So confused regarding ...
1
vote
3answers
274 views

KML to Shapefile using GDAL (LIBKML) - MultiGeometry data not transforming

I am trying to convert a KML file to Shapefile using GDAL (ogr2ogr). Regular KML files convert fine but KML files containing MultiGeometry features (eg: Geometry containing both Point and Polygon) do ...
5
votes
1answer
409 views

What is the unit of measurement for buffer calculation?

What is the unit of measurement used by Geometry class for it's buffer calculation ? Api doc currently defines it as " distance - the width of the buffer (may be positive, negative or 0)" I need to ...
0
votes
1answer
89 views

ArcMap toolbox script with draw geometries parameter

I have an arcpy script in toolbox, that need one additional parameter to draw geometry(ies) which will work as a filter. I have done something similar using arcobjects using ...
3
votes
2answers
3k views

How to remove duplicate features with the same geometry in ArcMap?

Is it possible to uniquely identify each geometry in a feature layer? Essentially I have a polygon feature layer with many rows of data represented by the same geometry. I would like 1 row for each ...
1
vote
0answers
84 views

Error When Generating INSERT Statements for Geometry Field SQL Server

I am populating a column of linestrings from a list of points in sql with which I use to create insert statements to populate an ID and a geometry field in a table. This creates a temporary dataset ...
1
vote
0answers
98 views

Inaccurate result while clipping on gis data

I am trying clip polyline data using a polygon geometry. I am using itopologicaloperator to do this task. However, resultant clipped data is off by 1 feet. Meaning that the polylines at the boundaries ...
1
vote
1answer
454 views

Intersection with JTS Geometry

I want to calculate an intersection between two geometries with the intersection function from JTS Geometry. What happens, if the geometries have different SRIDs? SimpleFeature sf1=...; //SRID ...
0
votes
0answers
173 views

Feature.geometry.transform not working

// World Geodetic System 1984 projection var WGS84 = new OpenLayers.Projection("EPSG:4326"); // WGS84 Google Mercator projection var WGS84_google_mercator = new ...
8
votes
1answer
238 views

What is the precision of SELECT DISTINCT on PostGIS geometry column?

I wonder what the precision of the SELECT DISTINCT operator is on a PostGIS geometry. On my system, the following query gives me a count of 5, which means that the inserted points are considered equal ...
7
votes
1answer
207 views

Draw middle ordinate perpendicular to chord, out to curve, with arcpy

I've been assigned to find the radius of road curves. My boss found this article describing a pretty straightforward method of doing so: find the start/end points of the curve; create a chord; ...
0
votes
0answers
185 views

Polygon to point conversion in ArcMap

I tried to convert polygons to point using Feature to Point under data management toolbox in arcGIS 10.2 (got it from uni. licensed). I got the point layer but it is not showing anything. I added X ...
2
votes
1answer
192 views

Retrieve geographic coordinates from OSM imported data

We have just finished importing OSM data into our PostGIS (Postgresql) database. And we are having difficulty understanding the geometry of various shapes imported. We run a query to retrieve the ...
0
votes
3answers
4k views

Get geometry from coordinates

I have a table with geometry column called point, saved in SRID 4326. I want to get the geometry by its coordinates, but something didn't work. I suspect database configuration or something. Here is ...
1
vote
0answers
130 views

pgRouting results to LINESTRING geometry type

I am doing some routing queries, using pgRouting's second version of pgr_trsp function. What I can't do effectively yet is storing the results. That is, I want to able to store in a table: either ...
2
votes
2answers
145 views

How to convert Point coordinates into CSV format?

The GDAL documentation describes how to convert a ShapeFile into CSV data. The layer create options (-lco parameter) allows to prepend the coordinates of Point features to the actual attributes ...
1
vote
1answer
60 views

Mismatch in area calculation using Field Calculator vs Group Stats in QGIS 2.0

I have two polygon files (A being my area of interest and B being a categorised land cover layer). Both layers were in the same projection (projected and not geographic). Using QGIS 2.0, I used the ...
0
votes
0answers
30 views

Identify primary routes in Postgis

I have a table of linestrings that make up a route network. I want to identify the primary routes and separate out the interconnections. Problem is that the primary routes are split into separate ...
1
vote
1answer
141 views

Get Polygon or IGeometry from Envelope in ArcObjects

I would like to create a Polygon Feature from the geometry of an IEnvelope in C# ArcObjects SDK 10. Is there an easy way how to do it?
3
votes
2answers
208 views

How to rename points by clockwise direction or change starting point in polygon features?

I have a polygon feature class. I convert it to a point. Name of field (for example !Number!) in a point feature converted from polygon "A2"(The first point should be in the upper left corner ...
7
votes
2answers
1k views

What is the best way to extract the geometry of a road from OSM data?

What is the best way to extract the geometry of a road from OSM data? The goal is to display segments of highway that are closed due to weather. The weather data consists of positions (in KM measured ...
1
vote
1answer
84 views

Clip geometries in table based upon value

I have defined a view in postgres that returns a set of polygons and can be queried as follows:- SELECT wkb_geometry, grade_count FROM ng_schema.grade_count_report [sql.where] order by grade_count ...
2
votes
1answer
713 views

How to write point geometries with arcpy instead of gp syntax?

Can someone help me fix some code that simply writes points into a featureclass? It used to work in the older gp. syntax, but I'm having difficulties rewriting it in arcpy for ArcGIS 10.0. In this ...
2
votes
1answer
398 views

How to get point x and y geometry from a shapefile?

I have a shapefile of US Cities and I want to get the X and Y coordinate of EACH city in that shapefile. I've tried this: for city in city_cursor: geom = city.Shape point = geom.getPart() ...
0
votes
1answer
85 views

How to automate creating box (rectangular) polygons in ArcGIS for Desktop?

Can anyone suggest a way to automate creating rectangle shaped polygons in ArcMap? If I had many 30m x 60m rectangles to digitize and I just want to click a starting corner coordinate on screen, ...
1
vote
2answers
434 views

ST_DWithin uses Geometry or Geography type

assuming I use the following query to match the locations to a poi within 10km distance: SELECT poi.poi_id, h.loc_id, (ST_Distance(poi.geom,h.geom)*111.111) as distanceinkm FROM iut_poi_transl AS ...
13
votes
5answers
407 views

What in-depth spatial database systems tutorials exist?

Is there a good tutorial that explains in depth the internals of a GIS and a spatial database system such as PostGIS with examples and without any background assumption? I'm specifically looking for ...
2
votes
1answer
164 views

How to modify the coordinates of a SHP geometry using Geotools?

I have a shapefile with some polygons. I would like to change the height for this elements using Java. The rest of the attributes should be the same. I've thought using GeoTools but I haven't found ...