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
4 views

CartoDB - Multipolygon not showing intersections

I'm having an issue with Multipolygons on CartoDB. I have a very simple scenario: A multi polygon row on a table that needs to be displayed on the map. Fact is that when more than two polygons ...
2
votes
1answer
20 views

Percentage of a polygon at, or less than, a specific height (supplied by a raster)

I am using QGIS to process some LIDAR data. I need to be able to define the area of a pond with respect to its depth (i.e it is 100m^2 at 32mAOD and 500m^2 at 33mAOD). Is there a way of finding the ...
9
votes
7answers
13k views

Get boundary of raster image as polygon in ArcGIS Desktop?

I have a rectangular raster image in ArcGIS. My question is: how can I produce a polygon which is just the extent of the raster image? That is, I want to have a polygon layer with a single ...
2
votes
1answer
27 views

QGIS calculates main soil type of polygons from another polygon layer

I've been working with qgis for a while but somehow I never fiured this out, so I thought it's time to ask. I have 2 shapefiles. a polygon layer from nearby fields (SHAPE1 (the red outlines)) a ...
1
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1answer
92 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 ...
3
votes
0answers
55 views

Why do each of my buffer-polygons have different areas

I`m using Qgis 2.2 and 2.4 and loaded a wms-map using the coordinate system ERTS89 UTM 32N. I set 8 points (all in on shp-fileand in UTM 32N) on various locations on the map. After that i created a ...
3
votes
1answer
201 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
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1answer
19 views

How to get list of all markers from selected Polygon using OpenLayer MAP v2

I am able to run following features on OpenLayers Map Version 2.x Put Markers on Map Draw Polygon on Map Select Polygon on Map Now my requirement is when i select any polygon then i would like to ...
1
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1answer
25 views

GEOS_ERROR: TopologyException: Input geom 1 is invalid: Self-intersection at or near point

I'm using GeoDjango (but I guess this is from the geos library). I have a set of polygons that compose a city surface and I want to merge them into a single one. The code looks like this: polygons = ...
-5
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0answers
30 views

How do i create a simple square polygon from Python through arcpy? [duplicate]

I do not need a google search result because I checked. I need to see a code. This has been super difficult for me. Please help.
-1
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0answers
42 views

Error creating polygons with ArcPy [on hold]

Based on the example from this page, running the code below results in an error message. Can someone take a look and tell me what I am doing wrong? import arcpy # A list of features and coordinate ...
2
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2answers
40 views

Mapping Russia - Int'l dateline splitting polygon

I am having the issue where the International Dateline is splitting a polygon I am working with. I have a layer of the "Federal Districts" of Russia, and the eastern most federal district is being ...
1
vote
1answer
275 views

How to perform 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 ...
1
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1answer
101 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 ...
3
votes
3answers
3k views

Polygon to Raster Tool Problem

I am trying to create a raster data set from county level polygon data for the US. I have successfully created one raster from a dataset, but when attempting another, it does not work. I am ...
3
votes
1answer
55 views

Shapefiles - Polygon type - is it in fact multipolygon?

I'm wondering about the ESRI shape file with shape type 5. When reading the spec I see that "A polygon may contain multiple outer rings.". Does this mean that these outer rings must be combined to ...
2
votes
1answer
13 views

Intersection between polylines feature to polygon in QGIS

I would like to transform a line shapefile into polygons. However, the tool Vector>Geometry>Line to Polygon doesn'to work to me. What I would like to do is using the intersection between lines and ...
0
votes
0answers
21 views

Create Polygon from same triangles [closed]

I want to create polygon from triangles. I have group of triangles which all have same normal. I want to merge triangle in single polygon. As a source code details, I have one vector of struct. ...
0
votes
1answer
25 views

Is it possible to join points to a polygon in MapInfo Professional v10.0?

This is what I have... ... and I would like to assign the points to the polygons that they belong to. In ArcGIS this is accomplished fairly easy through using Spatial Join, but I have no clue how ...
3
votes
3answers
84 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 ...
-2
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0answers
38 views

Totaling Population within A Polygon

I am trying to count total populations within several arbitrary polygons using census block data. How can I get a total number per polygon?
8
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1answer
152 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
vote
1answer
303 views

How to extracting raster data to multiple polygons?

I have a reclassified raster dataset (10 classes) and I want to find out the area of each class contained within multiple (hundreds-to-thousands) polygons. I have all the polygons in the same ...
1
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0answers
11 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
votes
2answers
231 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 ...
12
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5answers
17k views

Extract coordinates of polygon vertices in ArcMap 10?

I've got about a dozen polygons in a feature class loaded in ArcMap 10, all in geographic WGS 1984. How do I easily obtain the coordinates associated with each vertex of each polygon in that feature ...
6
votes
1answer
704 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
votes
1answer
37 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 ...
1
vote
1answer
114 views

autocad-map of real estates with own coordinate system and information to be converted to use it in QGIS

I have a question regarding CAD and QGIS, but unfortunately I don't have a clue of CAD. Here it goes: Real estates data has been mapped. There are several reference points surrounding the area. So ...
2
votes
2answers
66 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 ...
0
votes
0answers
19 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 ...
6
votes
1answer
120 views

Suitable algorithms for simplifying isochrone polygons

I'm looking for an algorithm for simplifying isochrones which were generated using OSM data. These are generally characterised as having lots of small "holes" mostly due to missing OSM data but also ...
3
votes
1answer
99 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 ...
0
votes
0answers
17 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 ...
0
votes
2answers
167 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. ...
0
votes
1answer
34 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 ...
1
vote
1answer
83 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
votes
1answer
46 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
votes
1answer
40 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
votes
1answer
33 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 ...
2
votes
1answer
167 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 ...
0
votes
1answer
35 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
vote
1answer
53 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
vote
1answer
16 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 ...
1
vote
1answer
56 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 ...
1
vote
1answer
104 views

How to get a centroid of a closed line in MYSQL

I have a table that contains only closed lines (lines where endpoint is the same as startpoint). I would need to find a centroid for those lines. How would I be able to achieve it? It does not ...
4
votes
1answer
241 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, ...
0
votes
1answer
45 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
votes
1answer
104 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):= ...
2
votes
3answers
3k 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 ...