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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22 views

How to merge DMAs using QGIS — Creating Custom Regions?

What I am trying to do might seem basic, but bear with me as I am just hacking my way through a lot of this space. What i am trying to do: I am trying to create a new .shp file of custom regions. ...
2
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2answers
343 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 ...
6
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1answer
1k views

Easily calculate “roundness/compactness” of a polygon

I am trying to find ways to quantitatively describe the shapes of various polygons. For my project, these polygons represent lakes, rivers, lagoons, and parks. So they can be almost any shape. One ...
3
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1answer
55 views

How to insert some holes in a polygon?

I have a problem with QGIS digitizing advanced tool plugin. I have a landcover-like shapefile. I have to perform some corrections on it, and I have to cut or split some polygons. I want to insert some ...
2
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2answers
70 views

Check if a polygon is at one elevation

I have a polygon (pond) and I need to ensure it is at one elevation. I have converted all vertices of the polygon to points, used summary statistics to determine the range in elevations and if the ...
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0answers
86 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 ...
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0answers
26 views

RasterToPolygon tool is looking inside the output location and not reading the fields

I am trying to convert IMG classified rasters to polygons. I created a code using the Raster to Polygon tool and it worked for 8 of the 50 files; for the rest, I get errors 010157 (Unable to open ...
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1answer
37 views

largest area polygon

I have a layer of polygon shapes, I know this could be a quite easy question to answer but I am a beginner and probably I am not using the right concept or terminology when looking at the desktop help ...
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1answer
113 views

Generate territory polygon from sets of points

I'm looking for a simple way to generate contiguous "territories" from sets of points. Say, points A, B and C are in territory 1, and D, E and F are in territory 2, then generate polygons that lie ...
2
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1answer
80 views

Convert Layer to Shapefile without losing Feature definitions

I have created a worldmap with custom defined Features, representing State/Zip-Code sales areas. I want to convert them into a Shapefile, so I can convert the Shapefile into a polygon definition file ...
0
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1answer
47 views

How do I measure the area difference between polygons in different shp files?

I have couple if shp files with 1000 polygons scattered in them (around 1k in each file) , each shp file represents a time frame (3 months period) and I want to show the a report with a progress of ...
0
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1answer
43 views

How do I calculate the distance of a segment of line that is inside a polygon?

I would like to calculate the distance of a portion of a line that is inside a polygon, as well as the portion that is outside of the polygon, based on from/to lat/long points on the line, and the ...
0
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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 ...
1
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1answer
62 views

How to hide grid's labels when zooming out?

I have used polygon grid layer on my map, and I used to label the layer with ID automatically, and the result was convenient for me: But when I zoomed out, the labels didn't hide at all! and they ...
1
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1answer
31 views

Point in zone problem in calculation

I have a strange problem that i believe its because the zone pass through international date line. My goal is to find if a point is within a zone and I use the geoPHP library, everything seems to be ...
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1answer
175 views

Convert Multipolygon Geojson to multiple geojson polygons?

I see a lot of questions going from Polygons to MultiPolygon, but is there some easy way to go the other way around? It would also be useful to preserve the attributes from the MultiPolygon to apply ...
4
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1answer
297 views

Clip polygon and retain data

I have these two polygons: library(sp); library(rgeos); library(maptools) coords1 <- matrix(c(-1.841960, -1.823464, -1.838623, -1.841960, 55.663696, 55.659178, 55.650841, ...
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1answer
108 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 : > ...
3
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3answers
4k views

QGis: Merge intersecting polygons into one which are part of the same feature

I'm not a GIS professional so I hope I use the correct wording, at least I hope you understand my question. Let's say there are 5 polygons in the feature A. In the shape file there are more ...
3
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0answers
50 views

What is the area that OGR extracts from the (geometry) shp files for polygons?

The ESRI July 1998 technical documentation for polygon shapefiles at page 10 makes no mention of either area measures or length measures (apart from byte/record-layout matters). Yet OGR enables me to ...
2
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2answers
69 views

Editing a Single Polygon Outline

Mapping geological contacts often needs true contact and inferred contact. I would like to know if it is possible to divide a single polygon outline which marks the outline of a granite body, so that ...
3
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0answers
51 views

Algorithm to find the boundary grid points [duplicate]

Let us consider a set S consisting of a collection of grid locations (i,j),i,j=1,\ldots,n, in 2-dimensional gridded plane. Here the point (i,j) corresponds to a rectangular grid in the X-Y plane. ...
6
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3answers
301 views

adjusting polygons to boundary and filling holes

here's the problem: Where: 1: department boundary 3: polygons inside department boundary that "touch" the department boundary(1). They are not necesary fitting well inside 2: holes between 1 and ...
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0answers
39 views

How to find the the boundary co-ordinates from a given set of coordiantes? [duplicate]

How to find the the boundary co-ordinates from a given set of co-ordiantes? I understand that this question asked previously and answered here How to find the boundary co-ordinates from a given set ...
3
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0answers
54 views

Dilating a polygon by a circle sector

I want to dilate a polygon by a circle sector in ArcMap. Because my python skills are not that good to figure out how I can use the R prototype of How to create an oriented buffer using arcpy? . Is ...
3
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3answers
70 views

How do I draw smooth vertexes around curves in ArcMap 10+?

I have some polygon layers (parcels) that have vertexes drawn around curves, as if traced. How do I click and drag to draw vertexes in a smooth shape? Big difference between what was originally there, ...
6
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3answers
1k views

Create a square grid polygon shapefile with python

i have the following coordinates minx,maxx,miny,maxy = 448262.080078, 450360.750122, 6262492.020081, 6262938.950073 i wish to create a square grid of size 1 m using python. import math ...
2
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5answers
283 views

Make a polygon out of a polygon's hole?

I have a large polygon with many vertices that has a hole in its center. I want a polygon of the hole, the empty space. How can I easily do that? (It is much too complicated to digitize easily)
2
votes
3answers
128 views

Removing small polygons gaps in a Shapely polygon

I know this issue has been addressed before with different software, but I am looking for an approach with Shapely. I have a polygon with a very small gap on the interior of the shape: Here is a ...
1
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1answer
51 views

Cutting polygons into smaller (more regular shape) chunks

I came up with a polygon shapefile like what you see here. There are some small polygons which exactly match what I want, though I want to cut(split) those bigger ones into smaller pieces. So far I ...
2
votes
3answers
3k views

How to aggregate points to polygons using ArcGIS Desktop?

I am trying to aggregate my data points to the polygons so that I could find out how many points I actually have in each polygon, and then export the data contained within each polygon to further look ...
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 ...
2
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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 ...
1
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0answers
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, ...
2
votes
1answer
218 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 ...
1
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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 ...
1
vote
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 ...
2
votes
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). ...
1
vote
1answer
51 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 ...
2
votes
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 ...
3
votes
2answers
2k views

How to subtract Geometry Point Polygons in OpenLayers?

I have two json arrays, one for background polygon and one for other polygon. And from them, I got two polygon layers. backgroundLayer = new OpenLayers.Layer.Vector("Background Layer", {styleMap: ...
1
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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 ...
12
votes
1answer
3k views

Instantiating spatial polygon without using a shape file in R

So, the usual way we read a shapefile in R is via the maptools package, like this: sfdata <- readShapeSpatial("/path/to/my/shapefile.shp", proj4string=CRS("+proj=longlat")) However, I have a use ...
0
votes
2answers
98 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?
1
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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 ...
4
votes
2answers
364 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
vote
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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vote
2answers
157 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 ...
4
votes
2answers
116 views

Wrong $area from field calculator (QGIS)

The area of the polygons in a layer, calculated by the field calculator with "$area" is wrong (much too big) for some polygons. If I draw the concerned polygon again, the area is calculated correctly. ...
5
votes
1answer
596 views

How to Create Touching Multi-Part Polygons?

I have a set of parcels as illustrated in the image below. There are currently no multi-part features in dataset. What I would like to do is to merge (not the right word) all of the parcels with same ...