On a map, a closed shape defined by a connected sequence of x,y coordinate pairs, where the first and last coordinate pair are the same and all other pairs are unique.

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0answers
45 views

API to find polygon for cities and administrative boundaries in India

I am new to GIS and learning basics by going through various forums. I am looking for a way to get polygon coordinates for any place (city, 2nd/3rd order administrative division) in India. I started ...
2
votes
2answers
975 views

Openlayers Vector Layer Polygons not displaying properly with OSM

I have an Openlayers map displaying Acetate tiles in OSM, and I'm drawing polygon regions on a vector layer to represent the countries of the world. This works fine for the most part, however, there ...
0
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1answer
24 views

ggplot2 plots polygons with wrong topologies

I'm trying to plot polygons in R using ggplot2. In GRASS, QGIS and normal R the map renders fine, but ggplot2 seems to have some kind of topological difficultes I can't explain. With normal R it looks ...
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1answer
21 views

polygon neighbors

Could you please tell me how to check in ArcObjects same feature overlapping other feature like (Building OID 10 and Another building OID 11) i tried to like below code but i am not going to for other ...
3
votes
1answer
140 views

How to map flood areas from a set of points containing surface and height of water?

I am working on the damages made by the typhoon Haiyan. I use QGIS 2.0 with extensions and toolbox, and MapInfo. I have vectors, rasters of the place. I want to map the flood area along the ...
3
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0answers
32 views

Adjacency matrix for polygons using Java

I am trying to create an adjacency matrix from a set of polygons. That is, I have a bunch of polygons and I want to identify which polygons have a common edge or "touch" each other. Once I find this ...
1
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1answer
67 views

CAD line drawing to GIS polygons pt II

I'm a (reasonably) proficient GIS user (mostly QGIS, but some Arc GIS) who has been thrown the conundrum of converting/importing CAD urban planning drawings (2D drawings produce in AutoCAD 2014) to ...
4
votes
1answer
128 views

Postgis 2.0 geographic polygon has max longitudinal range

My problem is that I have a load of geographic point data (srid 4326) in a table. A user may do a bounding box search - essentially create a polygon as follows: l_poly geography(Polygon,4326):= ...
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1answer
113 views

QGIS: How to add a second polygon that is exactly 5km larger in all directions?

Given is a map with an airport. Within a distance of 5km around the runway there is a so called no fly zone for drones (in Switzerland). I want to show this zone in a map. What I would like to do is ...
0
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1answer
21 views

How to merge polygons with ST_union

I have a similar problem, but I can't get the syntax correct. This refers to the following question: Merge polygons in CartoDB? I'm trying to merge multiple polygons into one (in this case, just ...
2
votes
2answers
124 views

A library to edit geometry in C#

For my windows application, I am looking for a method to edit vertexes and geometry of features that are stored in a SQL Server database. I just want a simple function for dividing polygons into 3 ...
0
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0answers
48 views

polygon shapefile R extract issues

I'm trying to do simple RF classification in R based on https://gis.stackexchange.com/a/39103/48810. The code I am using is as follows: require(sp) require(rgdal) require(raster) ...
3
votes
3answers
1k views

How to clip polygons with a fishnet layer?

I have a layer with multiple polygons (input) and a fishnet layer in polygon (clip layer). I want to clip the multiple polygons with the fishnet to be able to calculate how big portion of the input ...
1
vote
1answer
49 views

CAD line drawing to GIS polygons

I'm a (reasonably) proficient GIS user (mostly QGIS, but some Arc GIS) who has been thrown the conundrum of converting/importing CAD urban planning drawings (2D drawings produce in AutoCAD 2014) to ...
10
votes
6answers
2k views

Where can I get neighborhood boundaries?

Besides Zillow's creative-commons licensed neighborhood boundaries shapefiles, what sources of neighborhood boundaries are there? Not just in the US, but all over the world. Free/open source is ...
2
votes
1answer
96 views

Polygon centroid coordinates update error

After a week of unsuccessful fighting I'm forced to ask for your help. I have created a table 't_excavations' with fields 'id_excavation', 'geom' (MULTIPOLYGONE), 'longitude', 'latitude' CREATE ...
5
votes
1answer
2k views

How to take polygon centroid in Postgis

I have table with column name,Latitude and Longitude.I want to update this with polygon name and its centroid latitude longitude.I know there is a function in postgis st_centroid(geometry). But I want ...
1
vote
1answer
34 views

Connecting polygon accidentally deleted - filling in the gap

New QGIS user, Brighton 2.6. I accidentally deleted an elongated (lots of "peninsulas" polygon that represents a stream-based habitat - two gaps on SW boundary and two on the northern boundary ...
0
votes
1answer
109 views

GeoServer SLD: fill a polygon with color sampled from gradient

I have a "geometry" and a "rating" column. I want to symbolize the geometries in an SLD (PolygonSymbolizer) but fill it with a color value that is interpolated between BLUE-PURPLE-RED based on the ...
1
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0answers
69 views

Create diagonals in polygon with QGIS or ArcGIS

How is it possible to create the diagonals in/of polygons and to calculate the length of this diagonals afterwards. It's for a lot of polygons so maybe a fast/automatic method would be nice. I ...
0
votes
1answer
3k views

Dividing polygon layer into multiple layers by values in attribute table column using ArcGIS for Desktop? [duplicate]

I have polygon layer with multiple types of area (forest, grass, and many more), and I´d like to divide this layer into many layers by the area type. I´ve tried Split function but I receive an error ...
0
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0answers
26 views

Overlay polygons on raster in different projections

I'm overlaying polygons on a raster to get the average value inside the polygon (using SAGA->Shapes-Grid->Add grid values to shapes in the QGIS Processing Toolbox), using a geographic and a ...
1
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2answers
52 views

Using GDAL to get vertices of a multipolygon

I am successfully using GDAL to get the vertices of a polygon from a ShapeFile using .NET code. This link showed me how to do that: ...
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votes
0answers
15 views

Showing large number of polygons in SpatiaLite on Android map?

I have 2,300 complex multipolygon features in an offline SpatiaLite database. How can I show them on an Android map without slowing the map to a halt?
0
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1answer
35 views

Simplifying polygons in ArcGIS considering contains-one-point topology rule?

I want to simplify polygons using the "Simplify Polygon (Cartography)" tool in ArcGIS 10.2. Additionaly there is one point in each polygon and this condition should still be fulfilled after ...
0
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1answer
42 views

Clip multipatch to polygon ArcToolBox

I have a multipatch dataset and a 2d polygon. Which ESRI tool can I use to select only those multipatches whoms x,y are inside the polygon? Basically I want to select all multipatch features that ...
1
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2answers
127 views

Determine which points are contained inside a given polygon

I have these database tables defined: CREATE TABLE regions ( id SERIAL PRIMARY KEY, name VARCHAR(150) NOT NULL ) CREATE TABLE region_points ( id SERIAL PRIMARY KEY, region_id SERIAL ...
3
votes
1answer
288 views

ESRI/ArcGIS draw protractor

I am using ArcGIS maps and trying to follow JS API. I am trying to understand how can I add a protractor on the map which will help in angles while drawing polygons. I understand I could add a Feature ...
0
votes
1answer
49 views

Difference between a region and a polygon (mapinfo pro 12)

I am new to using MapInfo and have recently noticed the convert to regions and convert to polygon (edit: convert to polyline) function. What is the difference between a region and a polygon? Also, ...
3
votes
4answers
2k views

Clip a raster using a shapefile into multiple rasters?

I have a raster file representing a large area and a shapefile of 30 polygons representing watersheds. I would like to clip the raster with the shapefile to create 30 rasters representing each ...
1
vote
1answer
32 views

Enlarging polygons in a kml file

I have a KML file containing several hundreds of Polygon all around the globe, projected in lat/lon WGS84, decimal degrees. I need to enlarge all the polygons adding 23km at the top and at the bottom ...
1
vote
1answer
67 views

how to find that two polygon boundaries are connected?

I am working on a Geo database where there is a layer with many polygons. i want to find that which polygons boundaries are connected so that i can create new layer from that polygons and which ...
2
votes
0answers
41 views

Create polygons from many small. Expand to include space between

I'm just a programmer without GIS-skills as such. Hence this question: Intro: I have a lot of polygons; actually each private-owned real estate in my country. I also have "counties" as polygons. ...
2
votes
1answer
47 views

QGIS - Label outside polygon

is it possible to place a label automatically outside its polygon? Marcus
6
votes
1answer
303 views

How to compute Straight Skeletons using Python?

Is there a Python package which provides an implementation of a Straight Skeleton algorithm? I'm aware that the open source (C++) project CGALcontains an implementation but it seems like ...
0
votes
0answers
23 views

Bulk geocoded data of historic empires / countries of the world?

Is there an open dataset (of the likes of Pleidas) which provides geojson data (or similiar) of empires / areas of the world? There was a similar question here (link), however, I am looking for a ...
0
votes
2answers
51 views

How to calculate a set of minimum bounding boxes for a polygon

I need to calculate a set of minimum bounding boxes for a polygon. Id est having a complex polygon I want to envelope it with a set of small boxes instead of a big one.
1
vote
1answer
119 views

calculate the population inside a buffer with census data

I have population data matched with polygons and a set of points that I have drawn buffers around. Assuming that the population within each geographical area, i.e. the polygons, is evenly distributed, ...
0
votes
0answers
46 views

Raster to polygon with RGB composite using Arcgis

I am trying to convert an RGB composite to a shapefile to use with. The raster to polygon function returns with three shapefiles with "grid_code" of the value of each of these three channels. I am ...
3
votes
3answers
434 views

How to clean up a polygon by removing vertices and lines within?

After merging a set of shapefiles I've ended up with polygons that have vertices and lines within them. Is there a simple tool to remove these vertices and clean the polygon in ArcMap 10.2? I realise ...
1
vote
1answer
65 views

QGIS-->rotate polygon by a numeric value

Is there any way to rotate a polygon or a feature by entering a numeric value in QGIS thx
1
vote
2answers
67 views

Multiple polygon to shapefile in XYZ format

I have an array of gridded data in XYZ format. I am trying to write shapefile (*.shp) file with multiple polygons with the pyshp python libraries. I am able to make it for only one polygon with the ...
0
votes
0answers
28 views

What replaces SQLserver SqlGeometryBuilder, for Windows store apps?

Porting Visual Studio 2008 C# application to Visual Studio 2013, Windows 8.1 store\phone app (need to include DB with the application). What DB to use (coding in c#), to replace this code, not sure ...
0
votes
0answers
29 views

Parcels management and land ownership

Is it possible for me to split a feature by the column area i input?Like A feature has 3000 sqm and i have in attribute table column 1= 2000sqm and column 2= 1000 sqm and based on this 2 colums to ...
1
vote
2answers
93 views

Single polygon shapefile to multiple polygon shapefiles [duplicate]

I created a single shapefile that contains multiple polygons by selection by location of the route I had and the ESRI USA counties polygon layer to give me the counties that were in the area I was ...
1
vote
1answer
47 views

How to copy a line from polygon to an other polygon QGIS 2.6.1

I have a polygon(state) now the state divide into two. I have a new polygon with two state. I want to copy only the new border(line) which divides the two state from new polygon to old. I am ...
5
votes
2answers
99 views

Calculating edge length of polygon within overlapping polygon

I have a layer of wetland polygons and a layer of lakes. I basically want to find the total length of lake shoreline contained within each wetland and add these values as an attribute of the wetlands. ...
1
vote
1answer
46 views

How to create Spatial Reference System in QGIS?

I have some Attribute and the coordinate and the coordinate reference system. I want to create a DBmanagamet form my spatial data. To do that I want to create one table with name Spa_ref_sys, but I ...
6
votes
1answer
110 views

What do you call this non-hole edge condition?

After generalizing or simplifying polygons, you often get legitimate holes in polygons, which are separate parts and can be filled. But what is the correct term for this triangular shape? It is an ...
1
vote
1answer
141 views

Smoothly interpolating Polygons from set of coordinates?

I'm still quite new to QGIS and I'm using it to display and analyze my soil data. I have point information on the distribution of the soils in a specific area and I need to create a soil map from ...