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

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3
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3answers
288 views

Drawing some points in QGIS 2.4 using Python

I'm new to PyQGIS so here goes: Give a new QGIS project, how can we draw some Points on the map? I tried the following but nothing showed up. Should they be placed in a Vector layer before they can ...
1
vote
0answers
88 views

Assign a IGeometry to Feature.Shape

I'm trying insert a feature into a FeatureClass, but when I try to assign the geometry to featurebuffer the app return the next Error: The remote procedure call failed. (Exception from HRESULT: ...
2
votes
0answers
287 views

QGIS : cannot change the z-coordinate of a point shapefile using the wkb geometry format

I am using QGIS Desktop 2.5.0-Master with GDAL/OGR 1.11.0 on a windows 7. I am working on a little pyQGis script that should modify the z-coordinate of points in a vector shapefile based on a value ...
1
vote
0answers
129 views

QGIS 2.4.0 doesn't support multiple types of geometry in GML file

I'm testing GML 3.2.1 data according to INSPIRE Data specification (version 3.0). Data for theme Cadastral Parcels shall have both polygon geometry and definition point. When I download data from my ...
0
votes
2answers
377 views

How to store lat/long in PostGIS database? [duplicate]

I have a bunch of points in a text file that are represented using lat long (116.3158516 39.9748016). I import them into my GIS enabled database and create trajectories using st_makeline() as ...
1
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2answers
521 views

Count the number of points in a (multi)polygon in shapely?

I'm using Python, Shapely and Fiona to process some shapefiles. Is there an easy way to count the number of points in a polygon/multipolygon in Shapely and Fiona?
5
votes
1answer
434 views

how to compare geometries (contains, within) in arcpy?

I am trying to use 2 geometry objects to check if a line is within a (rather complex) polygon. The geometry check always fails, even if the line is clearly within the polygon. I use the following ...
0
votes
1answer
246 views

Add Marker on the polygons' centre using Openlayers?

I have written a code to draw polygon from the WKT format.Now I need to add the marker at its centre. In the following code I have passed the centre and shape in WKT format(extracted from database). ...
1
vote
1answer
768 views

PostGIS get geometries within a radius of n meters using WGS84 [duplicate]

select * from zones z where st_intersects(z.geom, st_Buffer(ST_SetSRID(ST_Point(2.336031, 48.863172), 3857),1)); It looks like the 1 in the st_buffer is being interpreted as degrees, I need to find ...
0
votes
1answer
248 views

selecting elements of a specific geometry type in PostgresSQL/PostGIS

I was reading a postgis tutorial and noticed that unlike working with shapefiles, one can actually store different types of geometry in postgres. In a table created with multiple geometry types, the ...
2
votes
1answer
97 views

Is a point within a polygon

I need help in this question. To explain briefly -- the question is: Whether a point with coordinates lng:-80.087535 lat: 42.054246 lies over or under line with coordinates: lng: -80.267831 ... ...
9
votes
2answers
1k views

why do people use geometry to represent geography?

Historically I've mainly worked with simple latitude and longitude coordinates in a SQL Server. I stored them as a geography datatype in SQL Server, and rendered them on a variety of displays ...
0
votes
0answers
23 views

Tools to generate all the possible geometries meeting specific constraints

I have an area = 2d polygon (generally a 4-side shape). I would like to generate all the possible rectangles matching the following constraints: that fall within the surface of the area with a ...
2
votes
1answer
288 views

Set default projection of geometry objects in arcpy

I have a script that creates a polyline geometry from scratch using some math to generate coordinate pairs. At the same time, there is a user-defined polygon shapefile that is used to "erase" the ...
1
vote
1answer
415 views

Is it possible to draw polygons along Google Maps Polyline?

Web application has option that user draws polyline on Google Map. After he draws it, there is a button 'Add polygons', which should draw polygons along that line, based on some width and height in ...
2
votes
0answers
170 views

Is there a way to eliminate duplicate 'point clusters' in SQL Server 2008 r2 spatial?

I am using the ST.Distance function to identify clusters of geometry data points. Each point has a unique reference number associated with it. I would like to eliminate duplicate clusters from the ...
0
votes
0answers
39 views

Software to determine if a position is within a shape

I would like to know if there is software available that can: Given a position detected by GPS, Warn the user if they are within a shape that I created and put into a database. Any computer ...
1
vote
0answers
30 views

Buffering/extrusion of a dem surface

I have a surface representing a DEM and i would like to add it some thickness. If i simply duplicate the surface and translate it down by my thickness, i get non uniform thickness, ie thinner where ...
3
votes
1answer
166 views

Extract longitude latitude and radius from POSTGIS column

I have entered the circle in the Geometry type column (name=shape) in my POSTGIS as following: ST_Buffer(ST_MakePoint($longitude, $latitude)::geography, $radius)::geometry Then I extracted the ...
1
vote
1answer
913 views

Get geometry from OpenLayers.Control.WMSGetFeatureInfo JSON

I need to store the geometry of a certain feature with OpenLayers.Control.WMSGetFeatureInfo and i'm using these parameters to get it in json format output:'features', infoFormat:'application/json', ...
1
vote
1answer
114 views

Changing order of parts in multipart geometry using ArcGIS for Desktop (or ArcPy)?

Is it possible in ArcGIS to change order of the parts in multipart geometry? In the context menu i founded "insert before" , "insert after" but it never comes active ... or is it possible via ...
4
votes
1answer
2k views

Calculating geometry area in ArcGIS for Desktop using ArcPy?

I have a polygon shapefile and I want to write a Python script to add a field named "area" and calculate its geometry areas. The script is like this: ...
1
vote
0answers
68 views

Why does the postGIS file lose geometry?

I am loading shapefile data from a GPS into PostGIS via Leica ZenoOffice. This apparently imports fine with it's geometry in the attribute table. However, when I add a postGIS layer in QGIS the file ...
1
vote
2answers
735 views

Export polygon in geojson as multipolygon

Anyone knows if is there any way to export a polygon layer in geojson, as multipolygon? I have a multipolygon shapefile. But there are single and multi polygons. When I export it to geojson, I got ...
1
vote
1answer
90 views

Geometry error in roadnetwork

I have a road network table. When I check st_isValid(the_geom)='f', I am getting an error: NOTICE: IllegalArgumentException: point array must contain 0 or >1 elements ERROR: Exception in ...
3
votes
1answer
1k views

Converting set of points to polygon using C#?

I want to convert a set of gps ponints to polygon.I used a simple loop to convert it to a WKT and than used makevalid() in sql server and save it in a gemetry column in databasae.Is this way right?or ...
0
votes
0answers
48 views

Drawing geometry and attaching it to featureclass with arcobjects and Add-in button

I am newbie to ArcObjects and exploring classes. I want to have form created on add-in button click.(Form contains certain text boxes for input) That shall create a new feature class and then allow ...
1
vote
1answer
136 views

Create a generic shape and draw it as a polygon with center (or base) and rotation?

In Java (jts), is there a way to draw a generic shape, eg. bounded in meters, and apply this to a coordinate, with rotation around a center or base? Something like: double lat = 65.100 double lon = ...
3
votes
2answers
154 views

Rotating geometry to specific angle using pyqgis?

I do not know how to rotate a geometry using pyqgis. Is there any sample/example code available to show me how?
2
votes
1answer
1k views

How to perform SQL query using .STContains in MS SQL Server

I have a table that stores polygons and a table that stores points with a value field. Both sets of data are stored using the Geometry type in MS SQL Server. I have a simple requirement - I need to ...
1
vote
1answer
382 views

Can't select geometry from Oracle DB using SQL

I'm trying to select the geometry field from an ArcSDE feature class in an Oracle 11g database (inside of a Python script via PyODBC). This is my query: SELECT SHAPE FROM USR.FEAT_CLASS This is ...
4
votes
2answers
299 views

Map location of unknown point with distances to two known points

I'm trying to develop a function in R that will locate a point (A) on a map given distances between that point A and two other points (B and C), for which exact coordinates are known. The problem I'm ...
3
votes
1answer
476 views

OpenLayers: How to get *real* centroid of a Line Geometry/Feature?

I have declared a line geometry as: var lineString = new OpenLayers.Geometry.LineString([source,target]); then I am trying to get the centroid of this lineString as lineString.getCentroid(). But ...
7
votes
6answers
6k views

How to fix quickly a lot of geometry validity errors in QGIS?

I am working on ownership data at a US county level. I have one shapefile per county that contains thousands of tax parcels. I need to dissolve the polygons representing parcels owned by the same ...
3
votes
1answer
38 views

finding the nearest point outside a series of geometries

I have db with a very large amount of geometries (circles), most of them overlapping. I'm trying to come up with a way to find the nearest point (from your current location) that is not within any of ...
3
votes
2answers
160 views

Is there a PostGIS function to get a tangent and normal line?

I'm looking for a function that will return a tangent (and normal) for a LINESTRING in PostGIS. I think this is the 3rd time I've come across the need for this function and everytime, I end porting ...
4
votes
1answer
497 views

How to calculate X and Y projected coordinate in batch processing

I have more than 1000 shape files (all are point features). They were initially in WGS 84. I projected them in UTM. Then through batch processing I added X, Y fields in each table. But all the X, Y ...
2
votes
1answer
329 views

Delete duplicate polygon nodes with PostGIS

I'm trying to delete duplicate nodes from a shapefile with QGIS, but after running the tool to delete it, nothing happens and shows the same errors. I thought that maybe importing to postgis could be ...
1
vote
1answer
91 views

ValueError when instantiating LineString from a mix of tuples and Point objects

I'm new to Shapely, and tried instantiating a LineString object from a mix of tuples and Point objects like this: >>> LineString([Point(1,2),(2,3),Point(3,4),(5,5)]) I get the following ...
1
vote
1answer
222 views

WKT: What is the reasoning behind the concept of a POINT EMPTY?

In data formats like WKT and WKB, we have ways of representing "empty" geometries. That all pretty much makes sense: a "LINESTRING EMPTY" is a LINESTRING type with 0 vertices. Same with a MULTIPOINT, ...
2
votes
1answer
313 views

Removing last point in polygon geometry using ArcPy?

This polygon was created from a grid of 500 x 500 meters, then Union, Generalize and Dissolve was used to arrive at this geometry, the laspoint not help me, I just want to have points on each vertex. ...
3
votes
3answers
204 views

How to display a table with more than one geometry column in QGIS?

In PostGIS, it is possible to use addgeometrycolumn more than once on the same table. Example: I have one table "scenes" with many attributes, and 2 geometry columns: the_geom1 and the_geom2. select ...
1
vote
1answer
299 views

Buffering a PointGeometry in arcpy only returns a line?

I am trying to buffer a PointGeometry object in arcpy to a Polygon geometry object with ArcGis 10.2. The PointGeometry object is in lat/lon WGS84 coordinates and as far as I understand, I can only ...
1
vote
1answer
166 views

Get coordinates from polygon outline with greatest distance

I'm looking into a task in ArcGIS 10.2 of which I need to discover the two points on a polygon outline where they would be at the greatest distance from each other. I have looked at ET Geowizards ...
1
vote
1answer
291 views

GeographyFromText and ST_SetSRID+ST_MakePoint different results?

Why am I getting different results? SELECT ST_DISTANCE( ST_GeographyFromText('SRID=4326;POINT(13.401111 52.383343)'), --berlin ST_GeographyFromText('SRID=4326;POINT(9.997559 53.533778)') ...
2
votes
1answer
202 views

Add XY Column in QGIS [duplicate]

Following on from a previous question of mine, where I was given coords in degree-mins, I have successfully converted them to decimal degrees, thanks for the help. I have created a CSV file from ...
1
vote
1answer
495 views

Openlayers WMS getFeatureInfo get features with geometry attribute

I am displaying map using WMSlayer and implemented WMSGetFeatureInfo control on wms layer. Tap on a location and get the features using WMS getFeatureInfo service. This service is returning me all ...
0
votes
1answer
205 views

PostGIS change column type varchar => geometry

I have a Postgres database with PostGIS extension on it. Also, I have a table with column lat with type (varchar 40). Column values are like this: 52.1432514 52.1431855 52.1431586 I want to convert ...
0
votes
2answers
147 views

Calculating Centroids with Zonal Geometry in ArcGIS

I have a shapefile containing polygons. Each polygon is defined by its postal code. I want to calculate the centroid of each polygon using Zonal Geometry. Sadly, for some polygons there are no ...
0
votes
1answer
45 views

Not empty geometry having blank text

i'm having problem with geometry column, for some rows i have geometry with blank text, this query will describe more the problem : select geom, ST_AsGeoJSON(geom), ST_Isvalid(geom), ST_IsEmpty(geom) ...