(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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0
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2answers
27 views

Calculate surface area of polygon within the lines of another polygon

I have two shapefiles, both polygons. 1) The first file represents the administrative boundaries of provinces. This file contains a lot of fields. [social, geographic, natural, morphological etc] 2) ...
3
votes
0answers
52 views

Using Check Geometries plugin for polygons in QGIS?

I've a few hundred polygon features with many duplicate nodes, gaps, overlaps and other geometry errors. Fixing all errors seems to be quite tricky. I had to run the duplicate nodes check twice to fix ...
1
vote
1answer
24 views

Distance from point stored in geometry with SRID 4326

I have stored 2.5 million data points (addresses) using the geometry data type in column latlong with SRID 4326. The latlon - column has a GIST index defined. I would select all addresses within a ...
1
vote
0answers
41 views

Resolving geometry errors in QGIS

I have a shapefile where the geometry is a mess, lots of gaps, slivers, and holes. I need to correct these geometry errors, but I am having trouble with the process. I have read the pages here, here ...
12
votes
5answers
478 views

What in-depth spatial database systems tutorials exist? [on hold]

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 ...
1
vote
1answer
223 views

Parsing large GeoJson geometry to WKT

I'm reading a very large json file as an InputStream in Android with JsonReader. This json has a geometry object like so.. "geometry":{ "type":"MultiPolygon", "coordinates":[ ...
2
votes
1answer
19 views

Does the GDAL GeoJSON driver read or write multipart geometries?

In the documentation for the GDAL GeoJSON driver, I can only see mention of primitive geometries. Does the GDAL GeoJSON driver read multipart geometries like MultiLineString? If not, is there ...
1
vote
1answer
545 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 ...
0
votes
0answers
10 views

How to acquire the geometry of a geoserver layer?

Is it possible to acquire the geometry of a layer stored in geoserver using the geoserver rest api? I am using gsconfig as: from geoserver.catalog import Catalog cat = Catalog(geoserver_location, ...
0
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1answer
21 views

ESRI JS API - Buffer FaetureLayer

I have a Feature Layer that I would like to buffer using user input and a geometry service. FeatureLayer: var texasPipeline = new FeatureLayer(pipeURL, { mode: FeatureLayer....
0
votes
0answers
24 views

Property “Area” not an option in Calculate Geometry

I want to calculate the area of a shapefile, but I the "area" property does not show up when I am in the "calculate geometry". Here is what I have done so far: I took a tracklog, used "points to line" ...
2
votes
1answer
23 views

Export geometry to WKT using pyshp

Is there a straight method to export shapefile geometry (polygon) to WKT using pyshp module for python? I was looking for something similar to OGR's .ExportToWkt() method, but it seems like there's ...
0
votes
0answers
17 views

Finding closest coordinate between geometries using OGR libraries?

I'm currently working on a project where I need to find the closest coordinate on a geometry using the OGR Geometry class. As far as I can tell the only easy operation to do with this class is ...
0
votes
1answer
1k views

SQL Geometry Query similar to Select by Centroid

Does anyone know if it's possible to query SQL geometry by something like 'centroid of polygon'...similar to ArcMap's select by location? I'm using SQL Server 2008 R2 as the DBMS. I have two polygon ...
1
vote
1answer
485 views

How to draw circles with a radius based on lat/long data in DB

I have a . sqlite file with many columns, two of those columns being lat and long. I've been searching around for a bit now (don't think I want to be using BuildCircleMbr from spatialite?) but I'm ...
2
votes
0answers
28 views

Making perfect rectangle in QGIS [duplicate]

I want to be able to set the height and width of my rectangles, as well as the angles. I have been trying the Rectangles Ovals Digitizing plugin, but I can't seem to make it do anything (besides turn ...
3
votes
2answers
134 views

Testing if Geometry is convex using JTS?

I'm using the Java Topology Suite and I'd like to efficiently check if a Geometry (a Polygon in fact) is convex or not. I currently do if (geometry.convexHull().equals(geometry)) but obivously that ...
0
votes
1answer
47 views

Drawing Queried Geometry using ArcGIS API for JavaScript?

I am new to all of coding and I have a rest point with all of my park polygons, what I want to do is be able to select a park name from a drop down menu and query out and display the single park ...
0
votes
1answer
183 views

Getting wrong value for area of geometry using Spatialite?

I am trying to implement a measuring tool on apple maps for IPAD. As a part of that i collect all the touch points on the map into an array and constructing a geometry object from that and then ...
2
votes
2answers
63 views

Save line geometry as points geometry in QGIS (pyqgis)

I have line and polygon layers. I want to make a list of points' coordinates (ends or begginings of lines), which are touching the polygons. The coordinates which I need are selected as yellow. ...
0
votes
1answer
19 views

Plotting on MAPinfo given edge geometry in a row

I have a file of road geometry of the Washington State downloaded from GIS cup 2012. Each row in the file is of the type, 5,service,15.9316766209136,47.2981713,-122.2481928,47.2981800,-122.2482596,47....
7
votes
0answers
269 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 9....
6
votes
2answers
590 views

Can ArcPy 10.1 be used to generate true curve elliptical polygons in a file geodatabase?

As background, this question arose from trying to answer a question on How to generate overlapping polygons from lines output from Table To Ellipse tool? Using the ArcMap GUI it is very easy to ...
0
votes
1answer
33 views

Single point creation

I am using arcpy.CopyFeatures_management(pointGeometry, "output") to create singles points. Is it possible to create those single points on an existing output without deleting the output before the ...
1
vote
1answer
26 views

PostGIS - ST_PointOnSurface and ST_Centroid dropping Z

I am using Postgres 9.5.2 and PostGIS 2.2.2. According to the documentation ST_PointOnSurface should not drop Z. This is what happens. If I run SELECT ST_AsText(cell) AS pt FROM cells LIMIT 1 I ...
8
votes
2answers
4k views

How to draw polygons from the python console?

I've been visiting and revisiting the page on geometry handling in the PyQGIS Cookbook: https://www.qgis.org/en/docs/pyqgis_developer_cookbook/geometry.html but can't seem to figure out how to get the ...
1
vote
2answers
39 views

Add a geometry in sqlite in pyqgis

I'm trying to create a geometry column in a table which I created. I found the following code: cur.execute('SELECT addgeometrycolumn(%s, %s, %s, %s, %s)' %(table_name, geometry_column_name, EPSGcode,...
10
votes
3answers
17k views

How I get SRID from Geometry field

what is the function for getting SRID from Geometry field. I have inserted a shapefile into SQLServer table with Geometry field defined. I know the projection of shapefile is Swreff99_1800 (EPSG:3011)....
0
votes
1answer
59 views

Calculate centroid of a point cluster

Having this function that inserts locations in a database: def insertLocation(cur, label, point): print label cur.execute(""" SELECT label, centroid, point_cluster ...
0
votes
0answers
24 views

Combining different geometry types in ArcGIS for Desktop?

Two geodatabases have been created using split by attribute tool from CAD drawing file. One gdb is from polyline layer and another from polygon layer of input drawing file. I want to combine ...
1
vote
1answer
1k 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', ...
3
votes
0answers
39 views

Style rule based on feature adjacency?

Is there a way in QGIS to use an expression to define a polygon feature's color based on whether it's adjacent to other features? I would like to achieve something like the following: -If a feature ...
1
vote
0answers
19 views

walk me through tdoa [closed]

I'm working on a TDOA application. This is just something in my free time to see if my hardware can accurately do it and it sounded like a cool challenge. Regardless if it looks possible or not, I'm ...
1
vote
1answer
38 views

How do I convert WKT geometry from 3D to 2D

I'm working with kml files using Python gdal.ogr module. When I extract feature's geometry using feature.GetGeometryRef(), I get: POLYGON ((44.184069865521963 41.971859752507207 0,44.355248797385123 ...
0
votes
1answer
34 views

How to calculate the start and end lat/lon of a linestring which is not a part of a ST_buffer?

I'm trying to find out the lat/lon of points on a linestring that are not contained inside a geometry formed by a ST_buffer. I can find if the linestring intersects the geometry but I'm not able to ...
1
vote
1answer
313 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 ....
0
votes
1answer
33 views

How to calculate nearest point to a linestring in PostGIS?

I'm following this question to calculate POI nearest a road(linestring). I'm able to calculate nearest points in the linestring but I'm not able to find the distance from the POI to nearest point(...
3
votes
2answers
87 views

ERROR: Only lon/lat coordinate systems are supported in geography

I'm trying to find out all the circles stored in the database(The circles are present all over the world) that intersect or overlap a given circle. I've stored the circles like this: CREATE TABLE ...
0
votes
2answers
212 views

Create point on a line with given distance from end in PostGIS

Does anyone know how to create points along a line (MultiLineString geometry) with a given distance in PostGIS? I'd like to create points at a regular distance over a line, which represents a ...
3
votes
2answers
2k views

ArcPy Data Access Insert Cursor not writing geometries to feature class?

I'm using PyScripter and running ArcGIS 10.2.1. I am having troubles with the Insert Cursor in the arcpy module. I have an empty feature class in my geodatabase and have created the short script ...
1
vote
1answer
39 views

Display selected features with same point geometry

I have a point layer and some features have exactly the same geometry. When I make a selection it seems that some features are not selected because they do not display with the "Selection color" as ...
6
votes
2answers
2k views

Unions of polygons (Postgis ST_UNION for Geography type)

I am looking for a function that will return the intersection of 2 or more polygons (geography type). I am aware of ST_UNION, ST_COLLECT but it works only for geometry type.
1
vote
1answer
40 views

Convert data type from bytea to polygon psql

I was trying to convert data type of my column from bytea to polygon, ALTER TABLE polygon ALTER COLUMN geom type polygon using geom::polygon; But I got an error saying cannot cast type bytea to ...
1
vote
0answers
19 views

Arcglobe 3D creating cones

For my school project I want to create a 3D image of certain earthquakes in a region. The data I received is the depth of the earthquakes, the location and the influence radius of the earthquakes. I ...
4
votes
2answers
106 views

Appending polygon feature classes with already repaired geometry => WARNING 000442: self intersections from Check Geometry?

I have an ArcGIS 10.2.2 for Desktop process which: Uses the Data Interoperability extension and the Feature Class To Feature Class tool to convert 88 MapInfo TAB files (with the same schema, ...
3
votes
1answer
68 views

How do I fill a combobox in QGIS with only points vector layers?

I'm new to writing plugins in python for QGIS. I've been searching on internet for a while and wrote the code below. Even though it fills my combobox, all layers (rasters, vectors of all geometry ...
0
votes
2answers
41 views

How to (precisely) re-align a polygon

I have this shapefile and I want to re-align the selected polygon (See image below) to the shapes of the other polygons. I tried using the "edit tool" but it's not producing a good result. What would ...
1
vote
1answer
32 views

Filter geoserver layers based on postgis geometry

I am wondering how, and if it is possible, to filter a geoserver's layer (from a large shapefile) on a specific geometry coming from a postgis table. I have a huge shapefile for a country. I'd like ...
3
votes
2answers
46 views

Tiny difference of calculated area of polygons

I have a shapefile of about 62.000 polygons. I calculate the area of each polygon on a field, named AREA1, with Calculate Geometry option. Secondly, I create a new field field named AREA2. I calculate ...
1
vote
1answer
31 views

CartoDB: Geometry code too long, Excel can't handle it

I am working on a map of regions where I want to be able to visualize some simple numbers on a periodical basis. I have a dataset with the polygons . However those are so detailed (the geometry is ...