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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1
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0answers
13 views

hiding some “feature”s in GeoJSON file on map

I have geojson file including boundaries of most countries in world. When I clicked on a "feature" (aka country, or polygon) I want to hide it while keep showing the others. because I am planing to ...
2
votes
1answer
29 views

JTS “points must form a closed linestring”

I'm trying to create a polygon and calculate it's area using final GeometryFactory gf = new GeometryFactory(); final ArrayList<Coordinate> points = new ArrayList<Coordinate>(); ...
1
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1answer
29 views

Split a polygon based on density of points in ArcGIS 10.1

I have two layers: Polygon layer representing administrative boundaries Polygon layer representing topography (i.e. a map) In some of the administrative areas, the buildings (shown in the map) are ...
1
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1answer
85 views

How do I peform a true GIS Clip of polygons layer using a polygon layer in R

I would like to do a true GIS Clip in R of soils polygons using a series of single boundary polygons, but I cannot find an R function to properly do it. It should work just like the CLIP function in ...
-2
votes
0answers
19 views

JTS Polygon Coordinates Order *DOES MATTER* For Some Reason [duplicate]

I'm trying to create a polygon and calculate it's area using : final GeometryFactory gf = new GeometryFactory(); final ArrayList<Coordinate> points = new ArrayList<Coordinate>(); ...
3
votes
1answer
91 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):= ...
0
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1answer
20 views

Using ArcGIS Polygon to Raster tool does not divide resulting raster on cells?

I try to create raster composed of small (5x5 m) cells (pixels) from a polygon in ArcGIS-10. I created a polygon (as a single object), and use Feature to Raster Tool and Polygon to Raster tool (of ...
2
votes
2answers
45 views

How to quickly fill multiple gaps in a series of adjacent polygons

I've been given a "background" dataset which is designed to draw as the first layer in a complicated map. For some reason the data provider has previously erased this dataset with roads, parks, etc. ...
1
vote
1answer
17 views

Filtering out a subpart of a polygon shape file

I have ArcGIS 10.1 for Desktop software. I am working with a polygon shape file (having n rows) in ArcMap. The project demands splitting this file into two polygon shape files having n1 and n2 rows ...
0
votes
0answers
14 views

Splitting existing polygons with existing polylines(roads) with GME tool “split polygon by lines”

After reading through many of these articles i believe the GME tool "split polygon by lines" should be useful to my problem. I have a polygon that needs to be split by a road layer. When i run this ...
2
votes
1answer
89 views

What methods exist for geohash of polygon?

GeoHash is an excellent method to code the latitude and longitude of a point into a string. It's concise, due to the use of numbers + letters, and the precision can be tuned adding characters at the ...
2
votes
3answers
197 views

How to change 0,360 WKT string to -180,180?

I'm reading POLYGON WKT strings using OpenLayers.Format.WKT().read(). The polygons use 0,360 longitudes but my map is -180,180. When I display the polygons on the map they are displayed outside of the ...
0
votes
0answers
8 views

openlayers clickevent for undercoat features polygon on multiple vector layers

I'm using two timers that give me coordinates and some data for my features (Sensors(de Sensoreinheit) & receiving unit (de Empfangseinheit)), deleting all features on the Layers and placing new ...
2
votes
0answers
22 views

Dividing a polygon into two OpenLayers

I'm using OpenLayers to draw a polygon to my users. I want the ability to implement through a line, split the polygon into two, with the cutoff line that the user drew. Does anyone know if this is ...
3
votes
2answers
88 views

Creating an outline around groups of polygons

I am trying to find a tool or workflow for creating a type of minimum bounding polygon or envelope for complex land areas. (Not just a rectangle, but a simplified perimeter) Can anyone recommend a ...
2
votes
0answers
32 views

Using R to subtract the polygon area of one shp file from another

I'm looking to produce a map from two separate maps in R. My Maps files are as follows: ftp://ftp.cpc.ncep.noaa.gov/GIS/us_tempprcpfcst/610prcp_20140822.zip #Map1 ...
0
votes
2answers
519 views

How to get a list of OSM relations (id numbers) of cities and countries only?

I want to get OSM polygon shapes (GEOJson or WKT) of countries and cities only. I know that it is called a "relation" in OSM and each relation has its own id (New York is 175905, for example). How may ...
0
votes
1answer
327 views

How to narrow the result from Nominatim with only cities and countries, no additional areas with the same name?

I'm trying to get WKT or GeoJson polygons of cities and countries from Nominatim (for example, Paris and France). I send a GET request but it returns me several results named "Paris" or "France". How ...
0
votes
2answers
142 views

Calculating minimum/maximum width for overlay of two polygon strips in ArcGIS or some Opensource GIS

Is there some solution for calculating minimum and maximum width for overlay of two polygon strips? When I clip these strips the result is another strip with variable width about 1 km and 20 km long. ...
1
vote
1answer
85 views

Step-by-step: How do I extract Raster values from Polygon overlay with Q-GIS or R?

I am writing my master thesis at the moment and am having the exact same problem as user Curley in this question: I first need to overlay a Corine 2006 raster with a polygon layer (2638 polygons). ...
6
votes
3answers
1k views

Can Polygons be generalized to MultiPolygons in GeoDjango?

I set up a model with models.PolygonField in geodjango, using postgres as database. I try to import shp into postgres. The problem is, shp (compiled with QGIS) mixes polygon and multipolygon, hence it ...
2
votes
1answer
122 views

Determine when I have crossed state line?

We are currently using the Google Maps API to get route information and total mileage but we would like to determine when we are crossing into a new state. When we return the route information we can ...
1
vote
1answer
16 views

Area of an EPSG 27700 polygon

I am working with EPSG 27700 polygon data in PHP. All the polygons are in the UK. The polygons do not have holes inside them. I'm hoping to be able to calculate the area of these polygons. For this I ...
1
vote
1answer
31 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 ...
4
votes
1answer
173 views

POSTGIS SQL - How do I remove (defined) sliver polygons

I would like assistance in writing SQL (for POSTGIS in postgresql) to remove sliver polygons (including long narrow slivers and some small irregular polygons that were erroneous 'gaps' in the original ...
1
vote
2answers
98 views

Making single polygons from a shapefile

I created a shape file a while ago with several (20+ polygons) in it. I was wondering if there is a way to symbolize these polygons with unique symbols. Basically all I actually want to do is color ...
0
votes
1answer
248 views

How to calculate the percentage of distribution in each polygon?

I have binary map for disease suitable area and I want to calculate the percentage using pixel count in each polygon how can I do that? I use zonal histogram and do have frequency for each polygon is ...
3
votes
1answer
58 views

How do I save a polygon once I have created it in editor?

I am attempting to create a new polygon. I go to ArcCatolog>New>Shapefile and make sure Feature type is set to polygon. I create the polygon and if I click save edits or stop editing, it disappears. ...
1
vote
1answer
97 views

QGIS: Clipping a line layer using a polygon and getting an empty shapefile

I am using QGIS 2.2.0 and want to clip a line layer (roads) so that only those inside a polygon are shown. When I do this using Vector->Geoprocessing Tools->Clip I only get an empty shapefile as an ...
0
votes
1answer
350 views

Reverse geocoding polygon co-ordinates?

I have a large dataset of polygons for property sections that I need to reverse geocode. It was recommended that I use a GIS like Quantam to do this however from my research I am not 100% sure if a ...
1
vote
2answers
31 views

Adding polygons from an existing layer to a new layer (shapefile)?

I have an existing shapefile that contains parcel data. I would like to add some of the existing parcels to a new shapefile. I am using ArcMap 10.1.
5
votes
2answers
2k views

Converting Longitude and Latitude Coordinates to Square Miles?

I have a set of Long and Lat co-ordinates making up a five point polygon which I have converted in excel using the following formula: ...
3
votes
1answer
166 views

digitizing (tolerence) error in line data

I have designed a large number of boundaries. For accuracy, I took lines in patches from different data sets and merged them into one. Now I want to turn them into polygons from lines. I every second ...
1
vote
1answer
18 views

QGIS create raster from cadastre (property lot data) polygon

I have a cadastre (property lots) polygon dataset of a region. Have used rule-base style in QGIS to show different groups of properties in the dataset classified based on their property lot size (ie. ...
1
vote
1answer
126 views

Calculate distances between polygon centres in QGIS

Is there a practical way to calculate distances between polygon centroids in QGIS? I have a UK city region map divided into administrative units (1 ward = 1 polygon). I want to represent their ...
2
votes
1answer
41 views

Delete duplicate polygon nodes with PostGIS

I'm trying to delete duplicate nodes from a shapefile with QGIS, but after running the tool to delete it, nothing happens and shows the same errors. I thought that maybe importing to postgis could be ...
0
votes
1answer
26 views

Drawing outline of points in ArcGIS for Desktop [closed]

Simple question, can Arc take a shapefile of points, calculate which ones are at the "edges" and draw a polygon or polyline around it. I know there are masks and bounding geometry and all of that, but ...
1
vote
1answer
36 views

Snapping with polgon drawing

I am drawing a polygon with the drawing function within ArcGIS 10.1. Is there a way to snap orthographically at 90 degrees while using the polygon draw command. I added a picture of what i would ...
3
votes
2answers
87 views

Remove Holes Existing Within a Single Polygon for a specific area in Qgis

I have a shapefile that consists of a single polygon. I have gaps within the polygon that needs to be eliminated, but only the ones that are less than 200m2. I tried different ways but none of them ...
3
votes
2answers
104 views

Add rectangle polygon

I have a polygon shapefile layer. I want to add a rectangle polygon (just like in Arcmap), and another one using the previous polygon edge. I need it to be accurate, my hands do not meet this ...
-3
votes
1answer
66 views

Extracting Cities, Towns and Villages boundary coordinates [closed]

How can I extract the polygon coordinates of cities,towns and villages from OpenStreetMap? Are there any other free databases available?
0
votes
1answer
142 views

How to generate random GeoJSON polygons (latitude, longitude)

I am looking how to generate polygons in GeoJSON format with random locations (latitude, longitude), if I generate totally random set of points it will not produce valid polygons. So my question is ...
2
votes
0answers
26 views

Showing Linestring from SQL statement with CartoDB

I have cartodb sql statement to return what polygons are intersected by a linestring, but I'd like to have the linestring visualized over the polygons on the results. Also not add the linestring to ...
2
votes
2answers
75 views

Creating donut holes without losing existing polygons using ArcGIS for Desktop?

Using ArcGIS 10.1 for Desktop is there a way to do a similar operation to creating a donut hole or island in a polygon without losing the existing features? I have mapped small lakes as several ...
4
votes
1answer
344 views

Determining if Polygon Contains Negative Space using ArcGIS SOAP Web Service?

I am running queries against a polygon layer using the ArcGIS SOAP Web Service. A user selects a point within that layer and the resulting feature set contains PolygonN objects. Occasionally, the ...
4
votes
3answers
5k views

Filling in Donut Polygons using ArcGIS for Desktop?

I have a set of polygons that represent bodies of water. In the same feature are polygons that are the islands in the body of water. So for a given lake, there are smaller polygons within that ...
2
votes
1answer
134 views

Separate a polygon in different polygons depending of the distance to another polygon

I have a reference polygon "R", and others polygons (in grey). I want to separate each grey polygon in multiple polygons, depending on the distance to R with different Buffers : - The red line is R ...
5
votes
1answer
152 views

Select by location of doughnut hole polygon

I have vectorized the Corine Land class raster and want to select certain classes that are "inside" other classes. How can I select the polygons circled in blue? All the select by location options ...
0
votes
0answers
42 views

Intersecting Overlapping Polygons Individually in ArcGIS

Map Layers: -Census Tract Shape File w/Population Data -Set of Store Locations with 5 Mile Buffers (Significant Overlap Between Buffers) I have create feature layers for both and I am trying to ...
4
votes
2answers
594 views

Including polygons as part of network for ArcGIS Network Analyst?

I am creating a pedestrian walking network of a downtown area. I am digitizing line segments for paths and sidewalks, but I need to incorporate parking lots into my analysis. So far, I have been ...