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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74 views

Invalid join selectivity error in postgis 2.1.3

I have 2 tables, one for points and one for polygons. I want to find points falling within theese polygons, so I quered: select p.id, l.id from points p inner join polys l on st_contains(l.geom, ...
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1answer
48 views

Join attributes from multiple polygons to an overlaying polygon

I have a polygon-shapefile, containing 562 single features (feeding -layer). I want to add their attributes to an overlapping polygon-layer (bear_buffer -layer), containing 1330 features. The ...
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2answers
118 views

How to draw polygons in shapefiles

I've hit a snag and realize this is probably a very simple and basic question, but how do I draw a polygon in a shapefile that I've created from joined points of 2 .csv files? Which specific tool do I ...
2
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2answers
80 views

Finding a point inside a polygon based on maximum value of a specific field

I have a Polygon Shapefile that represents US counties and a Point Shapefile that represents hospitals. The hospital attributes table includes fields like "Number of Beds", "Number of Patients" and ...
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1answer
50 views

IdentifyTask for “hollow” polygon (using ArcGIS API for JavaScript)

I have a web map application set up that's currently testing on a variety of Dynamic Map Service layer types, including points, lines, and polygons. This application includes a tool that makes use of ...
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1answer
79 views

OpenLayers: showing polygon within donut hole

I Am using OpenLayers 2.13.1 to display Zip-areas. I have a postGIS database with multi-polygons, that I show on a map. The user can select / deselected them. Some polygons have an area (I think they ...
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0answers
49 views

QGIS 2.4.0 doesn't support multiple types of geometry in GML file

I'm testing GML 3.2.1 data according to INSPIRE Data specification (version 3.0). Data for theme Cadastral Parcels shall have both polygon geometry and definition point. When I download data from my ...
2
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1answer
74 views

Polygon files corresponding to Russian Census

My team is using the 2010 Russian Census and we'd like to have polygons that correspond to these population values. We're flexible to any sort of polygon format (shapefiles, GeoJSON, KML, etc). ...
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1answer
107 views

clipping two SpatialPolygons : Error in RGEOSBinTopoFunc

I want to clip two SpatialPolygons on R without success, I followed the article in the disscution How to perform a true GIS clip of polygons layer using a polygon layer in R? Polygone 01 : > ...
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2answers
96 views

Count the number of points in a (multi)polygon in shapely?

I'm using Python, Shapely and Fiona to process some shapefiles. Is there an easy way to count the number of points in a polygon/multipolygon in Shapely and Fiona?
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0answers
32 views

How to use GIS data with CGAL?

I read a few posts here at GIS.SE that points to useful algorithms in CGAL. I'd like to test algorithms in CGAL such as medial axis transformation/polygon skeleton extraction, but the examples on the ...
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1answer
55 views

Convert raster to polygon based on cell value ranges using ArcGIS for Desktop?

I have a floating point-valued raster which I need to convert to polygon as follows Put the cells with VALUE < 0.5 into (a small/the smallest number of) polygons Cells in the range [0.5, 1] into ...
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2answers
363 views

Order of polygon vertices in general GIS: clockwise or counterclockwise

Two days ago I asked a question about the internal storing order for the vertices of a polygon in ESRI shapefiles. That question was answered (Are polygons stored clockwise or counterclockwise in a ...
1
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2answers
156 views

How to draw a polygon given a distance and bearing in QGIS

Apologies if this question has been asked before I'm not come across it. I want to draw a polygon given a length and a bearing, basically a square with lenght 1m. I cant seem to manage it with the ...
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1answer
54 views

How to add IDs of the links composing a polygon?

I built up a polygon layer from a road network for finding roundabouts using the compactness factor of a polygon. Then I have to intersect the extracted roundabout polygons with the road network so ...
3
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0answers
66 views

Geoprocessing tool for finding specific point within polygon

I have a ArcGIS task and cannot find a solution. I try to find a certain point within a polygon (see picture). This example is handmade and I need a geoprocessing solution I point I try to get is ...
0
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1answer
49 views

Add Marker on the polygons' centre using Openlayers?

I have written a code to draw polygon from the WKT format.Now I need to add the marker at its centre. In the following code I have passed the centre and shape in WKT format(extracted from database). ...
2
votes
2answers
138 views

Can't transform lines to polygons

I have a similar question to: How to join lines in QGIS for later using "lines to poly"? I have a line shapefile that I wish to transform into a polygon shapefile. After making some ...
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1answer
223 views

How can I convert GeoJSON with multiple Polygons and MultiPolygons into single MultiPolygon?

Is this even possible? I have a GeoJSON file with multiple polygons and multipolygons, and I need to set styling on them (in Leaflet.js). I'd like to create a single, large MultiPolygon from the ...
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1answer
82 views

How to clear areas outside map in R

I succeeded thanks to the eblonde in the disscution (problem with polygon smoothing in R) to smoothing polygons in R. Code: inter1= read.table("c:/inter2.csv", header=TRUE) #add a category ...
3
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2answers
405 views

Merge geojson polygons with WGS84 coordinate

I have a Geojson file with some adjacent polygons and I want to merge them into one. I know it's a recurrent question but I can't find information for polygons with latitude and longitude coordinates ...
1
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1answer
196 views

Find all street names or addresses within a polygon

I have a geojson list of lat/long coordinates that make up a custom polygon of a section of my county. Ideally I would like to be able to find all the addresses that are within the polygon boundaries. ...
3
votes
3answers
227 views

How to count the sides or edges of a polygon?

I wondered if it is possible to determine the number of sides / edges (not vertices) that a polygon has. Imagine the following case. There is a shapefile with 10 polygons. Is there any way to ...
3
votes
1answer
154 views

problem with polygon smoothing in R

With R I am looking to smooth my Polygon: inter2.csv code: inter1 <- read.table("c:/inter2.csv", header=TRUE) # add a category (required for later rasterizing/polygonizing) inter1 <- ...
3
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1answer
274 views

Polygon fill colour specified by column R spplot

I am trying to plot a geological map using the spplot function in R. For every unit I already assigned a specific color in the col-column of the SpatialPolygonsDataFrame. Now I would like to plot the ...
2
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1answer
42 views

SQL Server equivelent to Arcmap Intersect for polygons?

I have three different sets of GEOMETRY Polygon datasets in SQL Server that completely overlap. I need to create a new dataset that has a polygon for each unique area of the three layers. So ...
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0answers
35 views

Map polygon property in one shapefile to polygons in another shapefile with same outer boundary

I have two shapefiles covering a region with the same outer boundary. The polygon shape coverage (tesselation) of the two is different. One file (A) has a property assigned to each polygon. How do I ...
2
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1answer
216 views

Count overlapping polygons in single shape file with R

I have a shapefile of species ranges for ~ 346 species. Some species have multiple polygon ranges so there are 1,078 polygons and many polygons are multi-part. It looks something like this: I ...
2
votes
1answer
170 views

create polygons and fishnets of specific size and orientation and buffers

I want to study 6 areas in the field and in order to do so I want to divide each one of them into smaller areas/parts. What I would like to do is find an average square or rectangle area surface ...
9
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1answer
195 views

Cutting out the world into polygons of equal population size

I would like to cut out the world into polygons of equal population size, say 100 million persons (starting for example with raster data of population density as provided by the NASA). I know that ...
1
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1answer
145 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 ...
2
votes
1answer
72 views

Create a custom Identify dialog

How can I check if a point belongs to a polygon? I want to create a custom identify tool with edit option. I am using C# and ArcMap 10. My idea is to click on the polygon (building/park/etc) in ...
2
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0answers
77 views

Merge vector layers to fill gaps in QGIS

I have a zip code map which I added per zip code data too (a regional director for each zipcode), and then dissolved the map based on the director attribute. As you may or may not know, zip codes are ...
4
votes
1answer
535 views

How to find markers in selected dragbox openlayers 3?

Here is a part of code, draw = new ol.interaction.DragBox({ /* dragbox interaction is active only if alt key is pressed */ condition: ol.events.condition.altKeyOnly, ...
6
votes
2answers
149 views

Automate Splitting Polygons Into Sections

I've searched for similar problems on this topic but can't find a solution. I need to split many, many, many cemetery sections into 8 (mostly) equal pieces each. Each section is for the most part ...
1
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1answer
58 views

Looking for information on methods or algorithms used to calculate centroid from polygons across software

Looking for information on methods or algorithms used to calculate point centroids from polygons across software. ArcGIS uses a "gravity model" but can someone point me to the math or a paper on the ...
3
votes
3answers
117 views

Using SVG from Wikipedia to fill polygon?

I'm trying to use the flag of each region in Italy to fill each region's polygon. I have downloaded the shapefile of Administrative areas for Italy from diva-gis and am now attempting to fill each of ...
1
vote
3answers
90 views

polygons to polygon conversion with attribute name [duplicate]

1) I have a polygon shapefile with 1000 multi-part polygons in it. Each Row of the table is a multipart polygon. 2) I need 1000 shapefiles with 1 multi-part polygon in each. 3) Each output shapefile ...
2
votes
1answer
82 views

Get feature data from lat long input QGIS

In QGIS, I have a polygon dataset with feature data. I would like to extract data from this dataset using a latitude and longitude. To be more clear, I have a list of 1000 coordinates. I would like ...
2
votes
3answers
88 views

Summarize the total area of land use polygons within map sheets - how?

I would imagine that at least some of you have encountered similar problems to mine and I´d like to hear how you solved them. I have a map sheet index (a grid as a shape file) covering a large area. ...
0
votes
0answers
54 views

Display Google Maps Polygon Edge Distances in Meters?

How can I achieve this using the Google Maps API? The meters on each side.
1
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2answers
68 views

Dissolve tool misses out two polygons

I'm trying to dissolve polygons based on a code number in the attribute table. It all works well, with an exception of two polygons that fail to dissolve - they literally drop out from the output. It ...
1
vote
1answer
59 views

QGIS 2.4 How to label a polygon

I have tried labeling a polygon using the layer properties>label function but it doesn't show my label. How and where do I type the text I want and get it to show?
3
votes
2answers
297 views

Overlaying polygon filled with solid colour with diagonal lines in QGIS

I'm making a vegetation survey map using the UK phase 1 survey colour codes. The code for marshy grassland, for example, is orange overlain with purple diagonal lines. For the moment I've created ...
5
votes
1answer
291 views

Fixing orphaned holes in R

I'm trying to perform a union on a common field after merging two adjacent shapefiles. The shapefiles end up with at least one thin sliver of space between them. When I attempt a union I get the ...
2
votes
0answers
75 views

Extracting gridded data from polygon vector layer

So I've spent a few enjoyable (and frustrating) days teaching myself the basics of QGIS and fiddling around to try get some data output I need to drive some calculations. Sadly I'm not having any joy ...
3
votes
1answer
23 views

Bringing attributes of multiple polygons into other polygons?

I need to absorb multible attributes included in block areas into a number of ploygons. In other words, I need to bring block level data into a number of overlaying polygons. The polygons will absord ...
1
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0answers
69 views

Create Polygon with inner polygons from KML or Shapefiles?

I am creating a windows forms application and I want to create a polygon from a KML or Shapefile as a layer on top of a Google Satellite map. Today I am using GMap.NET that got an polygon object but ...
2
votes
1answer
195 views

Clipping Line shapefiles within extent of Polygon shape?

My question is an extension of Vertical lines in a polygon shapefile. Kindly refer to that question first. What you shall see there is a method of generating vertical lines with respect to the ...
2
votes
1answer
55 views

Joining QGIS extent table with shapefile

I used QGIS to find the extents of a list of features from a census boundaries shapefile. I used Vector - Research tools - Polygon From Layer Extent, which creates a new shapefile with a table of ...