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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9 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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1answer
59 views

Feature is a point or polygon

Im new to GIS and am just curious if there is an instance where a feature can be a point in one map and a polygon in another map and vice versa?
3
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2answers
65 views

Creating polygons from line segments using PostgreSQL and PostGIS

Is there a PostGIS function that creates polygons from multiple line segments? I want to convert the pictured thirteen lines to four polygons. All lines belong to the table "boundary" (gid, geom). ...
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0answers
21 views

Progress Bar gets stuck converting Lines to Polygons using QGIS?

I'm trying to convert lines to polygon using QGIS 2.8.1. I use Vector > Geometry Tools > Polygons to Lines. I always get the progress bar stuck on 90%, it can't get to 100%. Could someone ...
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0answers
26 views

Find what polygon geocode falls into [closed]

I have the KML code in a csv file for 180 different census tracts and the GEOID for each tract. I also have 130K geocodes. I know there must be a formulaic way to tell what polygon a geocode falls ...
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0answers
33 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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0answers
10 views

How do you snap polygons as you draw in QGIS? [duplicate]

I need to draw a long row of patient rooms for a hospital. I have the following plugins installed in QGIS 2.6: Rectangle Ovals Digitizing CAD Digitize I want to drag a set of polygons that aligns ...
2
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0answers
33 views

Different obs. when I extract raster values from polygons in R

I have two raster layers with the same projection, extent and resolution: r1: class : RasterLayer dimensions : 33434, 89431, 2990036054 (nrow, ncol, ncell) resolution : 0.001447053, ...
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0answers
38 views

Matching (joining) two slightly incompatible polygon shapefiles

I have two shapefiles that represent two slightly different zonings of the same area (municipality zoning and transport zones), about 3000 polygons each. Several smaller municipalities may form a ...
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0answers
29 views

Sample points based on underlying polygon attributes

I have a point shapefile and I would like to sample those points (just like the "Sample" tool allows points to sample underlying raster) to receive a table with underlying polygon values (interested ...
1
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1answer
19 views

Using pyQGIS transform a layer of polygons into a layer of holes inside a bbox

I'm using python in QGIS. I have a layer of polygons (its a result of some earlier dissolving and has no overlapping polygons but some holes and islands in holes etc). I want to build a new layer ...
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0answers
23 views

Selecting polygons using another polygon? [duplicate]

Hi, How is the best way or fastest(if there is) of selecting polygons of a different shapefile using a polygon of another shapefile. exercise example: i want select all the light brown polygons ...
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0answers
41 views

Why does the transformation bring bad results?

I have this map which has a polygon drawn on it. For the background map I use a WMS via ol.source.TileWMS and the polygon uses a ol.source.Vector object. Normally my view projection is EPSG:31467 but ...
1
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2answers
70 views

Is there any library can perform polygons buffering/ inflating/ merge/ overlap at server side?

I have a set of polygon data express in lat long. I would like to perform some tasks (polygon buffering, inflating etc etc ..) in server side and output the result to client side (client is a web ...
0
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1answer
23 views

Python error in polygon to raster conversion

I want to convert polygon to raster. I converted the dbf file ( "cntymam") to table view to make use in the conversion. I am getting a error that the parameters are not called and also with the grid ...
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2answers
38 views

How can I find internal overlaps in my polygon feature class ideally via modelbuilder tools?

I have a polygon layer containing "depth curves" for the making of a skin of earth kind of map. I want to check whether or not my feature class contain any overlaps internally between these polygons. ...
1
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1answer
47 views

Select points near polygon in Postgis

I'm trying to make a spatial query, but I think something is wrong with it: I have two tables, places (point) and cities (polygon) When I try to get the points within 500m to one point, there is no ...
2
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0answers
34 views

Redistribution of polygons: supplementing and filling the specific area with polygons with specific size

I'm studying the impact of green wedges (red outline on the figure) on weather parameters in Copenhagen area. What I want to do is check how spatial redistribution of future afforested areas enacted ...
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1answer
48 views

draw square openlayers 3

I am starting to convert old code of openlayers 2 to openlayer 3. In the old version you could make polygon shape based of the amount of sides like in the example below: ...
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0answers
41 views

Geofencing: Query if a POINT is within a POLYGON

I am trying to use the following query to search if a point is within a defined POLYGON (aka a geofence I want to define): ...
0
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1answer
45 views

Polygons of countries including territorial waters

Where can I get polygons (multipolygons) of all countries of the world including the territorial waters of the countries? OpenStreetmap displays these areas but I can't find an extract of this ...
1
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1answer
30 views

Adjacency matrix from polygons in GeoJSON

I have a set of polygon features in a GeoJSON file. They are neigbourhoods in Chicago. I would like to produce an adjacency matrix A, in CSV format or any other form, where the i,j element of A is 1 ...
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1answer
24 views

Assigning values from one polygon to second polygon if located within first using ArcGIS for Desktop?

I have two layers of polygons. I would like to know if there is a way to assign a value from a polygon in the first layer to any polygons from the second layer that fall within that polygon?
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3answers
45 views

Counting number of Raster Cells satisfying a criteria within a Polygon

I have a USA raster dataset, which assigns to each cell a value from 0-100. I also happen to have a USA county shapefile. I simply want a count of the number of pixels/cells in the raster data with ...
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1answer
36 views

Parts of geometry disappearing in QGIS export to Illustrator PDF

I'm having this issue with certain polygons when I export to PDF. Everything looks fine in QGIS, everything fine in print composer, everything fine in the PDF as viewed in Preview or Adobe Reader. ...
0
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1answer
55 views

How to scrape polygon data from web map?

for each value of parcel no: in http://www.ma-investment.gov.bh/bps_ppd_en/ the map generates polygons. I want to extract xy values corresponding to polygon shapes which i can convert to ...
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1answer
43 views

Measuring areas in WGS 84 [duplicate]

I started a QGis project with adding information layers from OpenStreetMap such as the streets and railways for a city. This data has WGS 84 CRS. After that, I made a shapefile with urbanized bodies ...
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0answers
35 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
27 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 ...
0
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0answers
67 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 ...
0
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2answers
43 views

Count objects in polygons

I have a .txt file containing the coordinate of the two polygons in the picture below as well as coordinates for each of the lines inside the polygons. Could anyone help to count each line inside ...
0
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0answers
25 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 ...
1
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2answers
63 views

Correlation analysis of two polygon shapefiles with nominal data

I am working on a research- trying to model vegetation types based on factors affecting their distribution. In that case I have observed a strong relation between vegetation and soil types, from just ...
0
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1answer
16 views

How to convert a specific multipolygon to minimum polygons

I've got this kml file with one multipolygon inside. A link for the file are here multipolygon.zip My goal is to get a multipolygon with the minimum count of polygons with only outer border and ...
0
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1answer
74 views

Draw polygons from an array in OL3

I have an query that produces an array of coordinates like so: 95.61,38.60 95.22,37.98 95.60,37.66 94.97,37.65 (long/lat separated by "," and coordinates separated by a space). How can I use these ...
0
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4answers
56 views

Fix Self Intersecting Polygons Manually

I are looking to implement a method to fix self-intersecting polygons by editing the vertex order. We want to take the polygon rings and re-arrange/add in vertices to make a valid polygon. This is ...
1
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0answers
28 views

QGIS, How to label a layer in different font sizes, shrink to fit in polygon or a multiple line label?

I am just trying to figure out how to label a polygon layer to fit its size in QGIS. or if its very long title should break in line and scale, i did some research but couldn't find anything helpful is ...
3
votes
1answer
29 views

Concentric Ellipses around polygons as a representation of density

I have someone who has given me a thumbnail of a map with some concentric ellipsoids placed in estimated high density locations for our business. One location has three, and two other location have ...
1
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0answers
23 views

QGIS Partitioning Regions

I have to polygon shapefile maps in QGIS that cover the same area. One with ~90 polygons (call them regions) and the other with about ~800 polygons (call them zones). I want to add a data column in ...
0
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0answers
31 views

QGIS - save vector poly layer into individual shp files? [duplicate]

Using QGIS v2.8.1, I have a directory of GeoTiff images. Using the raster ‘Tile Index’ plug-in (selecting “location” as the file index), I am able to create perfectly matched vector polys that I can ...
1
vote
1answer
51 views

dissolve polygons of GeoJSON with gdal/ogr

I have a GeoJSON with only polygons in it. I have to dissolve (merge) the polygons with the same "DN"-value. I found out that you can do it with shapefiles like this: ogr2ogr outputfile.shp ...
1
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2answers
35 views

how to color polygons with random color in QGIS

I have a map with a large number of polygons that I want to colour individually for display purposes. There is not particular pattern required, only to present them as individual catchments in a ...
2
votes
1answer
40 views

Extracting intersection areas in R

I have two polygons. One contains fields(X,Y,Z) and the other contains soil types (A,B,C,D). I want to know what area of every field contains which type of soil. I tried the following: ...
1
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1answer
28 views

Euclidean distance outside a Polygon (ArcMap)

I got some university coursework to analyse the best potential areas for a residential development project and I'm currently doing multi-criteria evaluation. One of the shapefiles in the dataset given ...
1
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1answer
25 views

Get Raster Values from a Polygon Overlay in ArcGIS

I have the same problem as Curlew in Get Raster Values from a Polygon Overlay in Opensource GIS Solutions and thecrashlandingdodo in Step-by-step: How do I extract Raster values from Polygon overlay ...
0
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1answer
31 views

Sampling one shapefile with polygons of another using R?

I have two shapefiles that partially overlap. One (the bigger one) consists of several polygons which represent fields I am interested in. The second, is a rectangular shape that overlaps about 30% of ...
0
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1answer
29 views

Copying attributes of one row to another row in polygon shapefile in ArcGIS?

I have a single polygon shape file in ArcMap with 25*25m grids, and I want to assign the attribute values of a single grid/polygon to another one close by i.e. copy attributes from a row to another ...
0
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0answers
70 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 ...
0
votes
1answer
27 views

ggplot2 plots polygons with wrong topologies

I'm trying to plot polygons in R using ggplot2. In GRASS, QGIS and normal R the map renders fine, but ggplot2 seems to have some kind of topological difficultes I can't explain. With normal R it looks ...
0
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1answer
22 views

polygon neighbors

Could you please tell me how to check in ArcObjects same feature overlapping other feature like (Building OID 10 and Another building OID 11) i tried to like below code but i am not going to for other ...