(1) abstract geometry; (2) storing geographic data in projected coordinates; (3) a generic ESRI term for vector features; a class for "geometry" objects.
1
vote
1answer
21 views
Combining polygon geometries with python and QGIS segfaults
I am trying to combine polygons, using Qgis 1.8, and every time I run this script in the python console, I get a segmentation fault. Here is the script:
from PyQt4.QtCore import *
iface = ...
0
votes
1answer
27 views
QGIS Python - Convert geometry from Postgres to QgsPoint()
I have made a query in Postgres to get some points to use with python.
This points are in geometry data. How can I convert that geometry in decimals to use QgsPoint() in python?
Thank you
1
vote
1answer
16 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
26 views
Python GDAL/OGR: check lines geometries connectivity
I'm working with shapefiles representing roads, so basically it's stored as (poly)lines.
I need to perform a road connectivity checking. In other words, I want to ensure that roads meant to ...
2
votes
3answers
98 views
How to test if geometry is inside another?
I need to tell whether geometries from a shapefile are inside other geometries or not.
For example, I want to test if there are trees (represented as points in trees.shp) inside the urban areas ...
0
votes
1answer
53 views
Is it possible to have measurements in centimeter and decimeter in 2D flat (geometry)?
Is it possible to have measurements in centimeter and decimeter in 2D flat (geometry) for ArcGIS?
2
votes
1answer
63 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 ...
3
votes
3answers
140 views
What Application for Vector and Cartesian Coordinate System
Goal:
Visualize a picture in SQL server 2012 spatial data based on geometry
Problem:
In order to display a vector picture I need to retrieve X, Y coordinate (cartesian coordinate system) and ...
1
vote
1answer
62 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
14 views
How to fix buffer selection issue in ESRI ArcGIS Javascript API and LGIM applications
I had strange LGIM application behavior where the map spatial search did not highlighted the parcels within the Geometry Buffer. What could be the possible reasons?
LGIM stands for the Local ...
6
votes
1answer
230 views
How to find the smallest-area ellipse circumscribing a convex polygon?
We are currently dealing with the problem of:
How to find an ellipse circumscribing a convex polygon?
Recent googling and lots of reading could not help me so much :(
0
votes
0answers
27 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 ...
3
votes
1answer
75 views
How can i topologically sort 2D triangles and put in an array?
I have a set of 2D triangles in a Geometry array which together forms a
connected strip when placed them according to edge adjacency. However, in
the array they are not in topological order based on ...
1
vote
1answer
46 views
Calculating area
I have a polygon layer.
I toggled to edit mode.
I added a new column, while number (integer) and called it "area".
I then use the field calculator - geometry - $area to populate the polygon area for ...
5
votes
5answers
768 views
Python, shapely library: is it possible to do an affine operation on shape polygon?
I am trying to create a rotated rectangle in lat/lon coordinates.
Basically I have the coordinates of the center and rotation angle around the center.
Is it possible to do using, shapely or gdal, or ...
5
votes
0answers
79 views
How to find the maximum-area-rectangle inside a convex polygon?
In this post we are looking for algorithms / ideas on how to find the maximum-area-rectangle inside a convex polygon.
In the following figure, numbers are the areas of the fitted rectangles. As shown ...
1
vote
1answer
31 views
Merge Multipart Feature Line
I'd try to merge multipart feature line, but didn't work.
would you please teach me how to merge multipart feature line?
I work in version environmental and geometry network.
Regards,
0
votes
1answer
58 views
ST-Links convert Feature Class to DB Table error
I'm using ArcMap with the ST-Links SpatialKit Conversion tool to convert a Feature Class to a DB Table. But I'm getting an error: ERROR: 42601: type modifier is not allowed for type "geometry".
I ...
1
vote
1answer
33 views
Postgis invalid geometry from shape file
I'm having trouble converting a Feature class (shape file) to a DB table (Postgresql 8.4/Postgis 1.5). This is the command in the pg log:
INSERT INTO "public"."distritos" ("Shape" , "DEPARTAMEN" , ...
9
votes
4answers
891 views
comparing two DEMs
i have two Lidar las files, one is original let's say with X points. And the other is copy of the first las file but with Y points, where Y is less than X. Now, i wanted to compare how the Digital ...
2
votes
0answers
35 views
What traits identify 2D, 2.5D, 3D geometries, and how can you convert downward, such as from 25D to 2D?
In answering this question, posed by @Burton449, I came to realize I don't have a definitive grasp on what distinguishes 2D, 2.5D, and 3D geometries. I certainly realize Z/elevation values are ...
2
votes
1answer
114 views
Reading OGC geometry data from SQL server using R
I would like to write a script in R that creates a map using OGC geometry data that is stored on a Microsoft SQL server. Is there a way to read OGC geometry data using a query passed from R?
Maybe ...
3
votes
2answers
179 views
Visualize Spatial Data in Reporting Service
Is it possible to visualize a piece of geographical map from SQL server Spatial data (geometry, not geography) in a report from reporting service? If yes, how should it be done in a course of action.
...
6
votes
3answers
225 views
What geometric attributes do polygons possess, and how can these be used to filter features?
Given a polygon featureclass containing many polygons of different sizes and shapes, which geometric attributes (area, perimeter, etc) could be used to filter the polygons? It's probably best to ask ...
2
votes
1answer
96 views
Can you explain this WKT multipolygon format?
I am confused by the output I'm getting from ogr2ogr when converting a shapefile to WKT. What I'm expecting to see is something in the form below (from Wikipedia):
MULTIPOLYGON (((40 40, 20 45, 45 ...
0
votes
2answers
97 views
Calculating area gets a different result
I've calculated the area of polygons with QGIS by using ctr-i - geometry - $area. I've set it on real. The results seem fine, but I've noticed they differ from the area given when I use the ...
0
votes
1answer
198 views
Make POINT from longitude/latitude coordinates from existing table in PostGIS
I would like to make a POINT using the longitude and latitude columns of an existing table. Here's a link to the documentation of ST_MakePoint.
Here's my table:
CREATE TABLE sysinst.bio (
oid ...
2
votes
1answer
120 views
How to split zAware polyline by points programmatically with C#?
I'm trying to split a polyline by the boundaries of a polygon using IPolyCurve2.SplitAtPoints using C#.
The polyline I'm trying to split is zAware and holds elevation values at a regular interval.
...
0
votes
0answers
27 views
How to populate polygon extents to an attribute table in QGIS
Is there a way to calculate the XMIN, YMIN, XMAX and YMAX of a polygon and write it to a field in an attribute table? The Geometry functions available in the Field Calculator are for points.
...
4
votes
2answers
572 views
How to calculate distance between two points with esri.geometry?
The function http://help.arcgis.com/en/webapi/javascript/arcgis/jsapi/#namespace_geometry/esri.geometry.getLength should calculate distances between points.
When I am trying to calculate distance ...
51
votes
12answers
12k views
Concave Hull: Definition, Algorithms and Practical Solutions
Convex Hull
A convex hull of a shape is defined as:
In mathematics, the convex hull or convex envelope for a set of points X in a real vector space V is the minimal convex set containing X ...
2
votes
0answers
56 views
Which is better for storage? Geometry column or varchar?
Objective:
Need to store and retrieve a list of geometries from the database. Basically these are drawn by the user using OpenLayers which I would like to save and present again as a list (kind of ...
3
votes
1answer
153 views
Geometry Conversion Problem
How do I convert from an ESRI.ArcGIS.Geometry.IPoint to an ESRI.ArcGIS.Client.Graphic point object?
In other words, I'm wanting to convert from an IGeometry to a runtime geometry, I guess.
3
votes
2answers
125 views
Several questions about using spatial data?
If you have spatial data for SQL server, can you use the spatial data (both geometry and geography) in another application for instance ESRI ArcGIS?
Is spatial data a standard that every GIS ...
2
votes
2answers
129 views
arcobjects update geometry Z values of line vertices with a given number
I am trying to develop arcgis 10.0 addin to update Z values of vertices of a selected line.
Scenario: The tool scans all features in a given shape file and populates the list of features which has at ...
5
votes
0answers
98 views
Why do file geodatabase and SDE readers produce different fme_geometry types?
I have one very simple workbench that I am running against both SDE (9.3) and FGDB (10.0) sources.
I noticed two different fme_geometry values for same type of objects.
For the first one, i.e SDE ...
1
vote
0answers
46 views
Retrieving ArcGIS:s Spatial Data into a Database
Background:
If you have created a vector map with lots of spatial data in geometry flat in with measurement kilometer. The following object that is used in the map will be point, line and polygon ...
2
votes
0answers
30 views
Find gap in / endpoints of linestring
I have a set of features of type linestring. I'm trying to polygonise the linestrings and assumed that they were closed (naive me :) ). Of course some were not closed and I'm trying to locate the gaps ...
1
vote
0answers
62 views
Programmatically change geometry column in OpenLayers WFS layer
is there a way to programmatically change the geometry column on which a WFS layer is based and displayed?
WFS (from GeoServer) is correctly returning me two geometry columns, I want to change "on ...
4
votes
2answers
148 views
PostGIS algorithm to unite points of two geometries that are within specified radius
I want to find an PostGIS algorithm to unite points of two geometries that are "near" to each other.
That is: I want a function, that takes as input two geometries, and returns 1 geometry, that ...
2
votes
1answer
145 views
Geometry valid in PostGIS turns out to be not valid in Oracle
Geometry is in PostgreSQL database. It is valid.
Geometry is exported as GML and then inserted into Oracle database.
Then function SDO_UTIL.RECTIFY_GEOMETRY(geometry, tolerance) is called, which ...
1
vote
3answers
83 views
How to Retrieve X and Y from a papermap or gif picture
Goal:
Visualize a subway map in SQL server 2012 spatial data based on the map of the subway.
The map shall use geometry, traffic rail road as line object, station as point object and zon as polygon ...
19
votes
3answers
2k views
How to find the minimum-area-rectangle for given points?
The following is another problem that I am working on it these days.
As you see in the figure, (BTW, I tried to make it self-presenter) the question is:
How to find the minimum-area-rectangle (MAR) ...
1
vote
0answers
53 views
Geoprocessing operations re-introduce geometry errors after “repair geometry” succeeds
I am working with a shapefile that has many small, detailed polygons. After exporting it to a feature class in a geodatabase, I found that some operations (for example, Snap in the Editing Toolbox) ...
3
votes
1answer
208 views
postgis error: when adding features geometry has z dimension but column does not
I have to define a geometry column in PostGIS for 2D points, but when I try to import points from DXF to postgres I get the following message:
"postgis error: when adding features geometry has z ...
2
votes
2answers
202 views
Updating polygon geometry: deleting inner rings with python
I've searched, but can't find clear explanations how can I simply delete inner rings from existing polygons with python or extract outter rings and overwrite the geometry. Seems GDAL/OGR should be the ...
0
votes
1answer
94 views
how to find vertices for a geometry in OpenLayers
I am having a LineString, where I need to find the vertices logically and save those vertices. Can anyone help me out. Or else how below can help me.
OpenLayers.Geometry.LineString = ...
2
votes
0answers
53 views
Critera for geometry or geography
What criteria do you need to take account to before you choose geometry or geography map?
Is there a book or page about it?
0
votes
0answers
49 views
Entity with Geometry column to JSON with Java / RestEasy / Jackson
How can I transform a entity with geometry column in a JSON to send via RESTEasy?
Thanks, Luciano
1
vote
0answers
173 views
Problems with Multipatches
I have some polygonal features that have minimum and maximum z values.
I'm trying to calculate the difference between a fixed extruded polygons and the sum of extruded related polygons.
Here's how ...
Related Jobs
Related Tags
postgis × 33arcgis × 25
python × 18
sql-server × 15
algorithm × 15
polygon × 13
arcpy × 12
openlayers × 12
qgis × 10
coordinates × 9
spatial-database × 9
arcobjects × 8
arcgis-10.0 × 8
shapefile × 8
postgresql × 8
geoprocessing × 7
spherical-geometry × 7
geoserver × 7
intersection × 7
buffer × 6
javascript × 6
convert × 6
arcmap × 6
topology × 5
ogr × 5
