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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176 views

Divide polygon based on points for even distribution

If I have a point layer, how can I create a polygon that includes all of the points and divide that polygon into n sections in which each section contains an equal number of points? Preferably in ...
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90 views

Convert polygon feature to line feature

I have a polygon shape-file i need to extract the line segments where the polygon features intersect each other and also the segment where they don't. Can we automate this process or can scripting ...
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107 views

how to avoid Intersection of polygons via python code

i am using QGIS 1.8 and i can set the check box in Setting\Snapping Options "Snapping and Digitizing " dialog to avoid polygon intersections and enable topological editing but i am looking for a way ...
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439 views

How to Smooth Polygons after converting DEM using Raster to Polygon?

I have a DEM SRTM that I classify using Spatial Analyst Tools > Reclass > Reclassify. The result is box shaped so I go to Layer Properties > Display and choose cubic convolution. The result is ...
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233 views

Divide polygon evenly based on lines and intersection points

I have this purple polygon illustrated in the figure below. I would like to split the polygon so that each line segment (green) split the polygon evenly with the surrounding line segments. A line ...
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2k views

How to write a point-in-polygon query for Postgis?

I'm trying to write a query in Postgis which will return all rows where a dynamically changing longitude/latitude point resides within the geometric polygon of that row (in the geom column). This is ...
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238 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 ...
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268 views

Point Within, Query in a buffer polygon in WMS like in ArcGIS ESRI

I need to do a query to filter the result inside a polygon or geometry, like this: http://help.arcgis.com/en/webapi/javascript/arcgis/jssamples/query_buffer.html But, i need to do this in a opengeo ...
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62 views

Are polygons created in Arcpy built in any order?

My script uses a search cursor to evaluate polyline coordinates and build polygons based on those coordinates. The script works well, but I am curious as to whether anyone knows the order (if there ...
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584 views

Line to Polygon via Polygonizer in QGIS

My question is in the same vein as this one. I'm attempting to convert precipitation lines (Precipitación Media Anual) to a polygon for Mexico in QGIS using the Polygonizer plugin. After running the ...
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266 views

How can I move two layers at once in QGIS?

I'm trying to move two digitized layers, one containing points, the other polygons to a different location at the same time. QGIS doens't seem to allow this. Even if I select both layers and features ...
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152 views

graduated pattern polygon fill

I'm sure this question is really really basic but I appeal to you because I hate the idea that I have spent 20 minutes trying to do such a simple thing... All I want to do is style a polygon layer by ...
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59 views

Avoid rounding of coordinates in pyQgis

If I get the coordinates of a polygon in qgis by x = geom.asPolygon() It rounds off the coordinate from i.e. -27,200,334.86 to -2.72003e+07 How can I avoid that?
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112 views

Is segment of polyline contained in polygon

I am pretty new to arcpy and am slowly learning all its functions. I have a scenario where I am traversing a polyline. I get a start point and an end point on the polyline and form a segment with ...
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32 views

Suggestions for vector format for polygons

I am using two polygon tables in postgis (A and B ). I need to make a vector file that incorporates information of the overlapped polygons B intersecting each polygon on (A). I can make a single ...
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68 views

When digitizing, objects are not saved well

I've some problems with digitizing. If I draw a line or a polygon, the line or polygon is saved in the attribute list, but not visible and its location is not saved either (when I zoom to the object ...
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648 views

How to clip the contour map with the polygon using R software?

Hi I am wondering how can I create the contour lines from the discrete x, y and z dataset and then add the shapefile to cut the contour lines by polygon. I want to clip the contour map by the shape ...
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847 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 $$ ...
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149 views

Creating responsive interaction with tiled maps

I think I may have two conflicting aims but... I need to create responsive Choropleth map very similar to http://leafletjs.com/examples/choropleth.html or ...
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141 views

identify the fraction of raster cells and listing all the cell values in every polygon

In Arcgis 10 I have a netcdf file that maps the fractions of cropland in the world from 1700 to 2007. I extracted the years that i needed as raster layer format (continous data from 0 to 1) and now, ...
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98 views

Getting started with storing LoST and GML searching

I am working on a logging and search database application. The application will receive event records containing XML LoST values (RFC5222 Location-To-Service-Translation). These records will be ...
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278 views

Export topology tables to txt files using ArcObjects, generating directed graph, and finding intersections

I want to export topology tables to text files: for points: 1 id x y for lines: line id fompoint.x from point.y topoint.x topoint.y for polygons: id line id 1, line id 2... 2 arc ...
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5 views

How do I search for features within a polygon in EarthExplorer or other freely available tool?

In USGS EarthExplorer, I'm trying to search for cemeteries within a defined area using a polygon created in Google Earth. If I select cemeteries under features, it clears that selection when I load ...
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12 views

Dynamic polygons grid with specified area based on raster

I'm interested if anyone have idea how to automatically create (maybe in R?) dynamic grid of polygons with specified approx. area (for example around 20000 m2) based raster data or points with values ...
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21 views

Finding how many points are in polygon of layer in specific time using QGIS?

I have the layer that I created with the number of earthquakes in each region in the last 400 years. I want to know the number of earthquakes that occurred in one specific region prior to 1900. How ...
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33 views

How to arrange polygon in Postgis

I have a lot of polygons in a Postgres database. I want to show the polygons, but in order of the the biggest to the smallest. I used the following code: SELECT ST_Area(area_polygon) as luas FROM ...
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39 views

summarize multipart feature by another multipart feature

I have one shapefile with many polygons, each representing the area of a selection of crops. I would like to determine the total area of each crop by county using a shapefile of counties in Arcgis ...
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27 views

Points nearest to polygon: nearest to edge of polygon or centroid?

When using ArcGIS and performing a Spatial Join of points to polygons, there is an option to choose the closest point. Is the point that is chosen closest to the edge of the polygon or to the centroid ...
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19 views

Aggregate polygons based upon adjacency to an acreage threshold

I work as a forester. I have a feature class of approximately 750 polygons that range in size from a few acres to more than 250 acres. I would like to combine these polygons based upon their proximity ...
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32 views

What is the best way to store GML polygons in MySQL?

I have large .GML files with polygons of regions around the country, some are a single polygon, some are multiPolygon. What is the best way to store this in MySQL? I was assuming that I would ...
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26 views

Merging two regions of several into one, to get output SpatialPolygonsDataFrame file

I've been using the large SpatialPolygonsDataFrame file with outdated border of regions. I want to correct boundaries, but also hope to get in the end Polygons with Data Frame again. I used the ...
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51 views

How to get a “clean” polygon after using dissolve in QGIS?

I'm trying to obtain the boundaries of shapefile, thus to clean the inside as a matter of speaking. While I had expected that dissolve while get me a proper polygon, unfortunately it still has some ...
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33 views

Convert polygons to optimized lat long radius

I have a research project where I need to search Instagram and Twitter for geo coded data. The APIs allow lat, long, and radius, but I have shape files with polygon shapes and some long lines (think ...
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22 views

Need to find polygon info from postgis

After importing shapefile into postgis I got geom data as MultiPoligon Like: ...
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75 views

Efficient way of determining polygon intersection with bounding box

I have a set of polygons, and I need to check whether they are intersecting with a given bounding box(rectangle). What I am doing is, I am taking every vertex of polygon and checking whether it's ...
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51 views

Visualizing overlapping polygons by occurence

I work in a library providing geospatial services and I have a patron with about 60 surveys with perceived accent regions in Mexico. Individuals drew on maps where they think people speak with ...
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17 views

Losing polygons when importing shapefile in GRASS

I have a complicated mapinfo .tab file of wildland urban interface zones. They are represented as polygons. I am importing into GRASS using the following command: v.in.ogr -c dsn="C:....path" ...
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0answers
48 views

How to properly import georeferenced .dxf hatches/polygons into QGIS?

I have a georeferenced AutoCAD-drawing (some district borders I vectorized with Illustrator from a raster image), saved as a 2004 ASCII .dxf-file. When I import the file in QGIS ("Add Vector Layer"), ...
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0answers
57 views

Grouping Analysis (Clustering) of polygons with streets as borders in ArcGIS?

I have a question about the Grouping Analysis Tool in ArcGIS. Is it possible to use streets as spatial borders for the groups? I want to group a city district autmatically with multiple attributes, ...
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40 views

Transforming GIS based XY data (polygons) so that they overlap in R

So I'm attempting to come up with the average shape of these polygon features as a part of my masters research. To do this, I want to run a shape analysis of GIS-based X-Y data using the shapes ...
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0answers
47 views

Clip Image by polygon and create memory raster

I need to write a code in c++ that can clip an image (4 bands) by using individual polygons in a shape file. I need to access the values of pixels (from all 4 bands) are clipped by a polygon. I do not ...
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0answers
81 views

Change SHP Projection to display on Google Map

I'm pretty new to GIS but not to programming, so sorry if this was already asked. I didn't find a solution not sure if I didn't quite understand everything about Projections and so on. I have a GIS ...
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0answers
37 views

How to convert points distribution toward surface information?

I'm working with QGIS 2.6 I have a points layer representing different bus and train stops. I applied a categorized symbology; each colour represents a class of value (field regarding time access ...
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0answers
177 views

API to find polygon for cities and administrative boundaries in India

I am new to GIS and learning basics by going through various forums. I am looking for a way to get polygon coordinates for any place (city, 2nd/3rd order administrative division) in India. I started ...
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75 views

polygon shapefile R extract issues

I'm trying to do simple RF classification in R based on https://gis.stackexchange.com/a/39103/48810. The code I am using is as follows: require(sp) require(rgdal) require(raster) ...
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0answers
39 views

Overlay polygons on raster in different projections

I'm overlaying polygons on a raster to get the average value inside the polygon (using SAGA->Shapes-Grid->Add grid values to shapes in the QGIS Processing Toolbox), using a geographic and a ...
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0answers
40 views

Showing large number of polygons in SpatiaLite on Android map?

I have 2,300 complex multipolygon features in an offline SpatiaLite database. How can I show them on an Android map without slowing the map to a halt?
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31 views

Bulk geocoded data of historic empires / countries of the world?

Is there an open dataset (of the likes of Pleidas) which provides geojson data (or similiar) of empires / areas of the world? There was a similar question here (link), however, I am looking for a ...
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0answers
97 views

Raster to polygon with RGB composite using Arcgis

I am trying to convert an RGB composite to a shapefile to use with. The raster to polygon function returns with three shapefiles with "grid_code" of the value of each of these three channels. I am ...
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37 views

What replaces SQLserver SqlGeometryBuilder, for Windows store apps?

Porting Visual Studio 2008 C# application to Visual Studio 2013, Windows 8.1 store\phone app (need to include DB with the application). What DB to use (coding in c#), to replace this code, not sure ...