(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

0
votes
1answer
25 views

Points shapefile resulting in MultiPoints table in PostGIS

I have a Points shapefile. When opened with QGIS, the type is 'Point' (right-click on the layer and check properties). When imported in PostGIS using pgAdmin III plugin 'PostGIS shapefile and DBF ...
1
vote
1answer
165 views

ArcMap: Output to XML Including Shape Data?

I need to create a solution for non-technical people to export data from an ArcMAP document (.mxd) to XML files. I will need each feature's data to be exported in such a way that the output xml file ...
1
vote
1answer
78 views

Is there any way to know if a polygon is part of another bigger polygon(s) in SQL server?

Basicaly, what I am trying to do is we have a lot of geographical containers like territories, sub-territories etc. and the boundaries of each keep on changing all the times and I have to store the ...
1
vote
2answers
235 views

Intersection point of polygon and the line created by two points ArcPy

I have polygon layer. I selected the most distant vertex from centroid (picture: point A). (How to do that is in the answer here: Select the most distant vertex from polygon's centroid using ...
1
vote
2answers
453 views

How to calculate the Oriented Bounding Box (OBB) of a polygon or point set?

I'd like to calculate the "Oriented Bounding Box" (OBB) which is the enclosing rectangle aligned to the longest extent of a point set (which is not necessarily aligned with the axes of the co-ordinate ...
4
votes
3answers
197 views

Select the most distant vertex from polygon's centroid using ArcPy

I have a poligon and the polygon's centroid. I want to select the most distant vertex from centroid (picture: point A). I used arcpy.FeatureVerticesToPoints_management to create a feature class ...
1
vote
2answers
977 views

Order sql server spatial geometry distance by the nearest

I have a geometry column in a table, I want to get the N nearest neighbours; here is a specific example with the geography type DECLARE @PTO Geography = Geography::STPointFromText('POINT(-57.432546 ...
1
vote
1answer
2k views

How to choose a SRID and what is its meaning? [duplicate]

I'm new to GIS, in PostGIS, and I'm struggling with the SRID concept. How do you choose a SRID for a database column? This is making me crazy. Why do I need to choose a SRID? What's its meaning? ...
2
votes
1answer
153 views

Difference between: join, merge and group

Suppose it is desired to make polygons A and B, and their respective attributes to be one unique polygon C. What is this GIS operation called? Is there any difference in GIS terminology about ...
6
votes
3answers
518 views

How to measure similarity of SpatialLines objects

I created two SpatialLines objects in R: . These objects were created this way: library(sp) xy <- cbind(x,y) xy.sp = sp::SpatialPoints(xy) spl1 <- sp::SpatialLines(list(Lines(Line(xy.sp), ...
1
vote
1answer
54 views

oracle VectorLayer without geometry - How to get attributes?

I have a prolem to iterating over a oracle VectorLayer without geometry in QGIS 2.6. self.uri = QgsDataSourceURI() self.uri.setConnection("localhost", "port", "xe", "name", "password") ...
3
votes
1answer
65 views

How Does One Calculate Angular Defect?

If I were to draw a 1km square on the earth what would the angles of the corners be? Obviously they would be a little greater than 90-deg but how would I calculate the angle exactly?
2
votes
1answer
119 views

Python library for geometrical calculations using with GRASS GIS?

I have to do some geometrical calculations in 2D(point, lines, line segments and intersection points) in Python, and then use it in GRASS GIS. What is the best library to use for it? I'm trying with ...
0
votes
1answer
221 views

Getting GPS coordinates perpendicular and parallel to AB

I already posted this question here And I got the solution thanks to Fang but the problem is that the coordinates I need to use are GPS coordinates and apparently GPS needs a different formula than ...
1
vote
1answer
176 views

Cover a polygon with fixed size squares

Can you please advice me of an algorithm (which I can implement in a Java) to cover some polygon (not exact cover) with squares of certain size (aXa squares)? The cover doesn't have to be exact - ...
1
vote
1answer
386 views

How to create postgresql triggers to calculate geometry from x,y and vice versa at the same time

I have a postgis table with point geometry which looks like this CREATE TABLE mypoints ( gid serial NOT NULL, coordid integer, geom geometry(Point,4326) ); And a table with coordinates ...
1
vote
2answers
430 views

add featureset in graphics layer without iterating

I have a geoprocessing service that returns a large amount of features (featureSet). I want to attach them in a graphics layer, but I dont wont to iterate over all them. I tried using the ...
3
votes
1answer
41 views

How to save shape file as type 1 point file in Qgis?

QGIS saves point shapefiles as type 8 - Multipoint as default. I need QGIS to save as type-1 Point file. How?
0
votes
2answers
292 views

MS Sql Server 2012 UnionAggregate geometry fails in ArcMap

I have following two geometries. Geometry 1 (G1): MULTIPOLYGON (((148.134707676 -34.1519003565, 148.143738823 -34.1540810687, 148.14648294 -34.1396863245, 148.143196834 -34.1392361445, 148.140859243 ...
2
votes
2answers
928 views

Ensuring SRID on geometry column in PostGIS

I am using a table that has a geometry type column called "wkt". Its definition in the table looks like this: create table sometable ( ... wkt geometry not null, ... ); I want to change it ...
4
votes
1answer
330 views

ArcGis label last vertex Z value

Is it possible to label a feature in ArcMap using geometry values? In this instance I want to label features (polylines) with the Live Z value of the last vertex obtained from the Shape. However ...
2
votes
1answer
193 views

QGIS crash when I try print geometry

I do (it works): from osgeo import ogr inputds = ogr.Open(r'c:\temp.shp') inputlyr = inputds.GetLayer() for i,feature in enumerate(inputlyr): print i, feature.GetGeometryRef() Output: 0 ...
0
votes
0answers
188 views

Array to Feature Class and XYZ to Table Issues

I am trying export vertices of a line to a point feature class using the code below. I am using ArcGIS 10.2.2 and do not have access to Spatial, 3D, or Network analyst. I used ET GeoWizards to export ...
1
vote
1answer
233 views

How to save changes in Feature-Geometry with GDAL/OGR and Python? (Segmentation fault)

I have a problem with my code: driver = ogr.GetDriverByName('ESRI Shapefile') dataSource = driver.Open('merge.shp', 0) if dataSource is None: print 'Could not open file' sys.exit(1) layer = ...
1
vote
1answer
89 views

Why are my points offset when using the Go to XY tool?

I am creating points in ArcGIS 10.1 to add to a GPS so I can navigate to them in the field. I add my points by editing an empty shapefile created in ArcCatalog. I then Add Field: Lat and Long as ...
1
vote
1answer
101 views

Defining polygons based on thickness maps using ArcGIS for Desktop? [closed]

I want to find and create polygons that demarcates three different inflection points in a thickness raster: where the thickness start to increase, where the thickness is at its max and where it starts ...
0
votes
1answer
124 views

Convert geography to geometry in H2GIS?

In H2GIS, geometry can be converted to geography with function "ST_Transform" For example: SELECT ST_Transform(ST_GeomFromText( 'POINT(584173 2594514)', 27572), 4326); -- Answer: ...
1
vote
1answer
238 views

How to calculate distances in QGIS field calculator?

So I'm using qgis 2.6.0 and I have a csv (converted into a .shp) with two geometry columns, I want to create a new column with the distance between the two geometry: shot.lat shot.lon haul.lat ...
0
votes
1answer
118 views

Adding geometry.type circle

I have to amend the following code so that on the map it's possible to draw a second circle graphic as well as a line, polygon and point. I've tried to add an else if statement much like the polygon ...
0
votes
0answers
32 views

Metrics of change between vector datasets

I have an old and a new set of parcel data which I'm looking to compare. I'm looking to compare changes in individual parcel geometries, so boundary/corner adjustment. Currently each parcel we have ...
2
votes
1answer
323 views

Use arcpy to check whether feature class geometry has ZM

I am looking for a programmatic way using arcpy to determine whether or not a feature class (FC) has Z and/or M geometry. It's easy enough to get the geometry type using the code below, but this just ...
1
vote
1answer
306 views

How to import geometry data from csv file to postgres?

I have geometry file in *.xls file, but when I save in *.csv it say "some feature in your workbook might be lost if you save it as CSV (Comma delimited)" however I keep that file anyway and when I ...
1
vote
1answer
80 views

Is averaging the points for lines and multilines a valid method of getting the centroid?

I'm working with a SqlGeometry SqlServer DB and am a novice to GIS. I'm tasked with getting the centroid of a series of geometries from C#'s SqlGeometry object. This is fine as it has a GetCentroid ...
2
votes
0answers
73 views

Needing to find parent zip code of a bunch of missing zip codes in the US

We're using MapPoint to export zip code / territory combinations. Unfortunately, the export doesn't include PO Box zip codes which mean that we're missing a lot of zip codes The PO Box zip codes are ...
7
votes
1answer
527 views

Find maximum radius of circle that will fit within an irregular polygon?

I have a problem which I think could be handled by using the Zonal Geometry tool in the ArcGIS Spatial Analyst toolbox. However I do not have a license for Spatial Analyst, so I am searching for an ...
3
votes
0answers
163 views

What is the area that OGR extracts from the (geometry) shp files for polygons?

The ESRI July 1998 technical documentation for polygon shapefiles at page 10 makes no mention of either area measures or length measures (apart from byte/record-layout matters). Yet OGR enables me to ...
0
votes
1answer
72 views

table update w/ cursor geometry conflict

I'm creating a table using arcpy with a list of results (stored in 2d lists) following an update to some features. This can sometimes include geometry, so I've attempted to substitute those for a ...
3
votes
1answer
171 views

Gaps and overlaps appear after cutting a previously topologically clean shapefile?

I'm using QGIS 2.2 and I have a polygon shapefile which was created by someone else. I have managed to get the shapefile to a topologically clean state by running v.clean but when I tried to cut the ...
3
votes
3answers
343 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
96 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
354 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
150 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
423 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
vote
2answers
657 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
556 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
297 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). ...
2
votes
1answer
923 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
291 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
101 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 ...