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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2
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123 views

CartoCSS: Don't show border between adjacent polygons

In OSM, riverbeds are created as multiple adjacent or even overlapping polygons. When styling these polygons in CartoCSS with a border, the overlapping can be seen: I'd like to hide that line ...
2
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0answers
76 views

Does converting polygon to raster generate more accurate results from the Zonal Statistics in Arcgis 10.2

I have heard the following for Arcgis 9.1 and wonder whether it is still an issue in Arcgis 10.2. If so, should I convert the polygon into raster before dissolve or convert the dissolved polygon ...
2
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0answers
230 views

Joining nearest neighbor small polygons using R

The figure shows a plot of numerous polygons (zoom in) made from a raster file by require(sp) require(raster) pol100 <- rasterToPolygons(r, fun=function(x){x==1}, dissolve=FALSE) There polygon ...
2
votes
0answers
149 views

Using ST_Affine() and trans_param() functions on vector layer

After reading this post How to georeference a vector layer with control points? I decided to give it a try to move/rotation/scale a polygon using Postgis. I have two polygons, polygon_from and ...
2
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0answers
283 views

Commit Feature WPS Split process

I develop a WebGIS application with GeoServer (2.1.1) and GeoExt (with the last version of OL). Data (polygons features) are stored in a postgis DB. I've implemented editing tools that allow users to ...
2
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0answers
269 views

Divide polygon layer by point layer in QGIS?

I have two layers - one polygon layer that is a buffer of a road layer, and one point layer that shows certain locations along that road. What I want to do is to divide/split the polygon layer at the ...
2
votes
0answers
528 views

Clipped raster leaks outside polygons

I am trying to clip a raster (DEM) with a polygon layer in ArcGIS10.1, using Data Management>>Raster>>Clip. Basically the clipped raster has many pixels outside the polygon boundary, mainly for thin ...
2
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0answers
182 views

Matching points in table to polygons

this is my first post to this forum. I hope to start participating actively. I have a table with several records (aprox 200.000), each with its own coordinates. And I need to identify the "Polygon" ...
2
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0answers
124 views

Cannot reselect polygon after modify

I've got various vector layers on a OL map. On one layer I have a few draw controls. If I draw a polygon I can select it (the whole pop-up thing works). This also works for all the other features. ...
2
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0answers
1k views

How to handle postgresql/postgis geometry type errors in a function?

I have created the following function in PL/SQL to make a polygon from a set of linestrings: CREATE OR REPLACE FUNCTION _myfunction( _fid integer, _rid integer ) RETURNS VOID AS $$ ...
2
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0answers
196 views

How to dissolve polygons that have been split back into their original polygons?

I had a feature class containging about a thousand polygons.After some processing such as intersecting, dissolving, merging, more intersecting, I ended up with a feature class of about 6000 polys. ...
2
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0answers
648 views

cant find point/polygon intersect using qgis (windows only)

below i describe the method i am using. i have 2 machines: 1 ubuntu linux, qgis 1.4 - intersection works 2 WIN xp, qgis 1.8 - intersection dows not work hopefully, someone will ...
2
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0answers
940 views

How to calculate the area of a polygon considering the relief?

I work in a fire department and i'm mapping all the fires that occur in my area, creating polygons that represent burnt areas. my problem is that the values are not accurate... for instance, arcgis ...
2
votes
0answers
231 views

Polygons of Land Use Change

I am doing a project where I am digitizing a map of Haiti from the 70s. Through R2V I digitized the lines and then I exported it into ArcGIS 10. I am just interested in the land use change, therefore, ...
2
votes
0answers
97 views

Determine which points fall within a 3D polygon and export this subset to a flat file

I am working in ArcMap 10 and will have a 3D representation of a zone of transmission. I would like to determine which GPS points fall within this polygon and then export this subset out to a flat ...
1
vote
0answers
11 views

Why does connected polyline (KML file) appear unconnect in arcmap as layer?

I created polygone in google earth and imported it to arcmap as layer. All things are OK but when I converted polygon to polyline, there some parts of polyline has not shown although its vertices ...
1
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0answers
21 views

Filtering Small Areas of Shapefiles Using R

I'm trying to use the method proposed by the @ialm in the Question "How to speed up the plotting of polygons in R?" There, he loads the maps using getData from the raster package, I tested and it ...
1
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0answers
16 views

Splitting polygon into multiple fixed-width polygons along edge in R?

I have a polygon and would like to spit into grid with fixed width along with one edge. The result will look like the figure below. Are there algorithm to achieve my target? My language is R, but ...
1
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0answers
21 views

Offsetting polygon borders where they share border in QGIS?

Say you have 2 polygons with different coloured borders, where the borders are shared the colour is problematic. How do you offset/separate them in QGIS 2.10.1?
1
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0answers
11 views

StreamingRenderer

I have a problem in my code (Java Geotools). When I draw in my carte map a LineString sometimes when I run my program an errors apears and I don't understand what does it means. Error: avr. 14, ...
1
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0answers
30 views

Forcing polyline to offset from polygon border

I am currently working on a site with polygons and polylines and am looking for a way to ensure that the polyline does not overlay the site boundary. I am creating a habitat map and do not want the ...
1
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0answers
50 views

how to separate land-use type from rows to columns from one shapefile

i am new to using ArcGIS. i have one shapefile of land-use data (100 rows) that has different land-use areas for each neighborhood (which are 10 neighborhoods), what i want is to have one row for ...
1
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0answers
26 views

How to assign a grid of point data to corresponding grid of polygons

I'm using QGIS 2/12.3 I have a point layer with modelled data on a 1km grid, each point has a value (0-5, modelling temperatures) and lies at the centre point of a 1km grid square. I also have a ...
1
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0answers
38 views

How to correctly rasterize a polygon which crosses 180E longitude?

I want to rasterize a polygon wich crosses 180E lon with gdal_rasterize. The polygon is in the WGS84 projection. I used the following command: gdal_rasterize -burn 1 -of GTiff -ot Byte -ts 1500 ...
1
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0answers
21 views

Convert a polygon grid into an edge table

I'm working on a robotics project. I've got a rectangular grid (polygon shape file) that is a navigateable/routable region (i.e. I can travel anywhere in this grid). That is I took my bounding area ...
1
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0answers
55 views

Problem in polygon division using the union tool from QGIS

I am trying to overlay two polygon layers using the union tool from QGIS, to then compute the areas from the resulting polygons. However, in the resulting layer some polygons are not divided as ...
1
vote
0answers
81 views

Calculating area of intersection of polygon to another layer in ArcGIS for Desktop?

I am very new to GIS, especially ArcGIS. I am currently using ArcGIS 10.2, and I have 2 layer, namely the purple feature map(this layer is an import from arcgis online, it doesn't seems to be an ...
1
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0answers
48 views

Spplot SpatialPolygonDataFrame and SpatialGridDataFrame

I have to plot in the same graph something like this: Then, I have elements from SpatialPolygonDataFrame class and others elements from SpatialGridDataFrame class. When I try to plot them in the ...
1
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0answers
37 views

Selecting certain area of polygon according to size in ArcMap?

I have a set of polygons with a certain size (3500 sq meters each for examples). I only need 3000 sq meters of every polygon. Is there an automatic or semi-automatic way to create sub-polygons out of ...
1
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0answers
28 views

Polygon to Raster tool while keeping less than maximum values

I'm trying to convert a very large, detailed polygon to a raster with a coarser resolution in ArcGIS 10.1 using the polygon to raster tool. The value field is a percentage and the cellsize must be the ...
1
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0answers
44 views

create polygons using 2 coordinates

I have a script that creates a text file containing the upper left and lower right coordinates of my geotiff files in the following format. TileName UpperLeftX UpperLeftY LowerLeftx LowerLeftY I ...
1
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0answers
31 views

Point and Polygon Data refusing to display: corrupt data?

I have two sets of shapefiles, one point data and one polygon data. Both were sent as part of a bigger set of data. Neither the point or polygon data will display when loaded into QGIS. The raw data ...
1
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0answers
29 views

Split Polygon Layer by other Polygon layer in QGIS

I know there is a lot of previous posts to this subject, but I simply cannot find the solution I am after in the other posts. I have to following problem: I have two very extensive polygone layers, ...
1
vote
0answers
33 views

Polygon overlay, calculating changes, in QGIS?

I'm trying to create a relationship file between two vintages of census tracts. (in this case, 2010 and 2013.) Reason being to load ACS (American Community Survey) census data and use weighted means ...
1
vote
0answers
23 views

Showing polygon in OpenLayers Timeline?

I am trying to use the OpenLayers TimeLine library with a kml file. I used the available example for kml in github, but it shows points instead of polygon. How can I display polygon the TimeLine ...
1
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0answers
33 views

Rotate functions in “Rectangles, Ovals Digitizing” as well as “Advanced Digitizing” distort shape dimensions

I am trying to rotate squares via the rotate tool in the "Rectangles Ovals Digitizing" Plugin in QGIS. The dimensions/proportions of the sides, however, are distorted whenever I do so. Any idea of why ...
1
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0answers
23 views

Create a center node based on both polygon and line shapefile

Sorry for cross posting. I want to develop a node layer from two other layers. One of the layers is a polygon contains a series of zones. Another layer is a line layer of roads. The nodes I want to ...
1
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0answers
23 views

How to show neighboring polygons and polygon in which point exists

We have a table which has polygon related data stored. For finding if a point (long,lat) is within that polygon I am using following query in mysql SET @vasantKunjSectorC = 'polygon((77.161266 ...
1
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0answers
27 views

Wrong shape type

I am from statistics, and I need to do a fast cartogram. But I am getting this error from ScapeToad: Error processing record (a):160 PolygonHandler.read() - got shape type 1610612760 but was ...
1
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0answers
71 views

Polygons within Polygons Spatial Analysis

I have a polygon layer of planning applications and I am wondering if anyone can give any advice and or has seen or written a blog post that might point me in the direction of creating relationships ...
1
vote
0answers
33 views

How to recognise building type from polygons?

I have a number of building polygons which are extracted from the aerial images, along with their postal address. (The aerial images are not available in my case.) For example, the polygon of a square ...
1
vote
0answers
42 views

Toggling selected feature when using Node Tool of QGIS?

Does anyone know of a way, when using the Node tool in QGIS to edit a polygon, to choose or toggle which feature (within the same layer) is being selected if they share a boundary? It seems to just ...
1
vote
0answers
79 views

How to show two layers at the same time in Qgis

I have a question about Qgis layers. I want to see two layers at the same times. one is lines which are boundary lines and the other is polygon which are district. when i was surfing about this ...
1
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0answers
69 views

QGIS split line into segments on polygon

Is it possible in QGIS to split a line into segments given which polygon it falls within? I am using 2.8. For example, a line that passes through three polygons will become three separate lines. Each ...
1
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0answers
46 views

Enable editing only one feature in a Polygon Layer using PyQGIS

I was thinking of locking neighboring polygons (parcels) by disabling editing on them, while editing would be possible on the polygon at the center. This means other polygons can also be edited in ...
1
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0answers
27 views

“Impossible to engage a segment in the current layer”

How can I fix this ? My problem is the red "x".
1
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0answers
120 views

PostGIS: intersection of a polygon with 2 rasters

I'm trying to get the intersection of a Polygon with 2 raster layers in PostGIS. The rasters have the same size and pixel size and I'd like to retrieve for the polygon a list of something like that: ...
1
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0answers
82 views

Query to merge simplified polygons according to the map scale-factor

I'm trying to construct a view in PostgreSQL that simplify polygons according to the map scale-factor. Basically I was reading this thread ...
1
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0answers
82 views

XYZ bounding box of a spherical polygon

I'm looking for an algorithm to calculate the 3d bounding box of a spherical polygon - i.e. the min/max X, Y and Z over that part of the surface of a unit sphere. The purpose is to aid fast ...
1
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0answers
39 views

Lines > Polygon artifacts

I am trying to make polygons from a set of boundaries from an SVG file with closed polylines I downloaded off wikipedia. 1) convert SVG to DXF via Inkscape 2) import into QGIS (shows polyline data) ...