(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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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', ...
1
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1answer
17 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 ...
-4
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1answer
33 views

Getting nearest feature point from other features in point layer? [closed]

How i can do this Get the nearest feature point from the other features point in a point layer Point feature class and make it in script tool
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1answer
29 views

How to use the new Geometry Generator to get rectangle from point?

I would like to translate a point (from a point layer) to a rectangle polygon using the new Geometry Generator from QGIS 2.14. I know the length and the height of the resulting rectangle. The point ...
2
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1answer
42 views

How to render mixed geometry from one table?

I have a table in postgresql with mixed geometry, but it is not accessible in QGIS. I am running QGIS version 2.8.2. Is there any plugin to install for QGIS to render multiple geometry?
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1answer
516 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 ...
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1answer
25 views

Verifying whether point lies on line or not when both given in GCS?

Googled and tried to look on Esri's forum but couldn't get anything. Rather got things which were verifying if the point is within a polygon or not. But I want to know, if I have starting point and ...
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1answer
2k views

Choosing SRID and what is its meaning? [closed]

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? ...
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0answers
47 views

How to implement a shoelace formula into Python 2.7.8 [closed]

Here's the image of the equation I'm using, it is a shoelace formula. I need help to point out what each variable represents and how to apply this in python script, math is not my strong-suit! From ...
3
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1answer
33 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 ...
0
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2answers
180 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 ...
1
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1answer
298 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 ...
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1answer
60 views

Transform to SRID 900913

How i can transform the geometry WKB for example: ...
2
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0answers
20 views

Path Matching for Journeys Using XY Coordinates [closed]

I am trying to find some suggestions on ways or algorithms to determine path similarity. An illustration of 3 paths using made up data is given below. The title should be finding similar paths instead ...
0
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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 ...
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1answer
55 views

Postgres/PostGIS calculate area of Polygon in Square Miles

Polygon in Postgres/PostGIS database. It has the spatial reference 4269 which is in degrees. I know there is a ST_Area() to calculate it. this is my query to select the areas in the SRID units. ...
1
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1answer
207 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":[ ...
3
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1answer
40 views

ESRI shape curves specification

The documentation for ESRI's File Geodatabase API (downloadable from http://www.esri.com/apps/products/download/) says regarding its MultiPartShapeBuffer Class: These functions provide access to ...
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3answers
82 views

Searching for changes of 2 layers based on geometry, Arcgis for desktop (ArcEditor

I´m trying to make a tool that would be able to compare 2 layers of any type (polygon, point, polyline) and find differences between them. Lets say i have a layer of roads (Polyline) from 2005 (layer ...
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1answer
451 views

SQL Data: 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 ...
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2answers
556 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 ...
3
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2answers
4k views

Downloading Google Maps municipal geometry

When searching for a city on google maps, google is that smart it displays a geometry line on the boundary off the municipal. See this link: http://g.co/maps/23dz5 Is there a place in the google maps ...
5
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0answers
42 views

How to update null geometries from an attribute [duplicate]

I have a large point feature class and have realised that there are several hundred features with null geometry. Fortunately the coordinates are stored as an attribute. So What I need to do is update ...
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0answers
27 views

Request long/lat precision and request too slow [closed]

I've a PostGIS DB of 18Gb. The tab node (id, tags, geom) is very huge and I need to request long/lat on this table but it's very long when I'm using this sql request : SELECT * FROM nodes WHERE geom ...
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2answers
22 views

Over-calculation of area due to parcels occupying same space

I'm trying to get the total acreage of different parcels by land use, and unfortunately I keep getting a total of ~15000 acres instead of ~12000 because it's over-calculating the area where there are ...
1
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1answer
23 views

Getting Error: Districtna.getExtent(…) is null

I have dojo combo box to display district names when I select one district it should zoom to that particular district.selection is working fine but zooming not happening i am getting ...
2
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1answer
46 views

Why can't save changes on GeoServer layers via QGIS?

I am using QGIS 2.14 on Windows 10, and GeoServer 2.8.3 on Windows 2008 Server (VPS). QGIS manages my GeoServer layers with Web Feature Service. I would like to change the geometry or attributes of ...
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0answers
15 views

MapGuide Fusion OpenLayers 2.13 ModifyFeature - how to get input object from Fusion…?

I'm looking for a way to pass the Fusion object's selected geometry into OpenLayers.Control.ModifyFeature to initiate an edit session for the user. Non-Fusion Example: ...
4
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4answers
333 views
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2answers
151 views

Transform geometry to coordinates

I need transform with postgis a geometry of type ...
5
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2answers
144 views

Are there any multipolygons in my shapefile?

In QGIS 2.x, is there a simple way to determine if a polygons layer contains multipolygon geometries and if yes: which are these features?
4
votes
1answer
39 views

Change feature class from ESRI native geometry to SQL Server geography

Original question: I have found a lot of documentation on importing and using query layers from SQL Server into ArcCatalog/ArcMap/etc. However, when you change the projection of a feature class or use ...
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0answers
44 views

How to use the “geometry generator” to intersect geometries with an entire layer in QGIS?

In the "geometry generator" style in QGIS, it's possible to define an intersection for a specific geometry of an other layer like this: intersection($geometry, geometry(get_feature( ...
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0answers
21 views

Can you merge GeoJSONs in PostGIS?

I'm not too familiar with the GeoJSON functionality in PostGIS. In essence - I'm having problems with the computation of ST_AsGeoJSON(ST_Union(g)) taking too long for large g. Is it possible to ...
3
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2answers
1k views

How to densify a polyline according to a specific length? [duplicate]

Possible Duplicate: Add vertices to lines I am using QGIS 1.8.0 I would like to densify a polyline according to a particular length of segment (ex. 200 m). I know it is possible with other ...
2
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0answers
64 views

Geometry issues when digitising in QGIS

I'm digitising a large number of maps from hand drawn mud maps and digital images, and although I have used the snapping tools ("snap to vertex and segment", Tolerance 10 pixels, avoid intersections) ...
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0answers
13 views

Converting polygons to contours based on value in polygon table

I have the following and data and have been asked for a map that shows the same data set but displayed as contours. Each polygon has a value in it's table called "count". The "count" field is used to ...
10
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4answers
345 views

How to snap a road network to a hexagonal grid in QGIS?

I'm trying to use QGIS 2.14 to snap a road network to a hexagonal grid, but I'm getting strange artifacts. I've created a hex grid with MMQGIS, cells are approx 20 x 23 m. I've buffered the road ...
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1answer
28 views

How to use “geometryEngine” in arcGIS Version 3.9

We are using arcGIS javascript version 3.9 in our portal. Now we have new requirement to do reverse clipping on map. We have already written code to implement reverse clipping with the help of ...
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0answers
26 views

Handling empty PostGIS geometries with GeoServers Pregeneralized Features extension

I've setup my GeoServer instance (2.8.2) with the Pregeneralized Features extension to serve several large polygon layers from PostGIS (9.3), and while it is working I am still experiencing remarkably ...
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0answers
36 views

How to calculate a Label Point for a (multi)polygon [duplicate]

ESRI software has a concept of a 'label point' for a (multi)polygon. It is like the centroid, except it is guaranteed to be within the (multi)polygon. Like for a U-shaped polygon, the label point is ...
3
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0answers
49 views

Interpolating point to nearest polygons to compute street width in posgis

I am trying to calculate the width of streets (line.shp) in postgis using reference point (ref_point.shp) (yellow point features) and building polygons (building.shp). The red point features are the ...
1
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1answer
33 views

How to check point intersection with bbox made from two points?

I have two points which represents lower left and upper right point of BBOX. I have one point which SHOULD be somewhere inside and I want to test it. I have all of them as 'geometry(POINT, 4326)' ...
7
votes
3answers
1k views

Is there a way to “invert” Polygons?

I have a Shapefile with Polygon features representing the world's land areas (continents, islands). Is it possible to invert these, and get a geometry that represents the world's oceans and seas? So ...
4
votes
2answers
207 views

Is it valid GML if the boundary of a polygon intersects itself?

Is it valid GML if the boundary of a polygon intersects itself? E.g. I have this polygon consisting of some gml:LineStingSegment and one gml:Arc: My task is to import GML based data (german ALKIS ...
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1answer
2k views

Moving graphics in Esri Flex Feature Layer

I have an ESRI Flex 2.3 FeatureLayer with some graphics in it. I am able to access the graphics geometry and parse the geometry as Esris MapPoint class for Flex Api. I am calling the update(x,y,srs) ...
88
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13answers
28k views

What are Definition, Algorithms and Practical Solutions for Concave Hull?

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
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0answers
25 views

How to resolve a rectangle with know points? [closed]

How do I find the coordinates(lat, lon) for D and E in the following rectangle? I know: A (lat, lon) B (lat, lon) C (lat, lon) AE, BE, AC
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0answers
30 views

Multi-select / modify event Openlayers 3

I'm trying to incorporate a modify feature where the user will move a point and any underlying geometry is also modified. Currently to draw a route on a map I'm taking points from a database and ...
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2answers
920 views

How to convert features of layer from POLYGON to MULTIPOLYGON?

How can I convert features of a layer from POLYGON to MULTIPOLYGON? I know how to do that using the postgis function ST_Multi but how could I do to same thing for a layer in QGIS?