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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1answer
31 views

Auto-Create polygons from Geo-referenced PDF

Is it possible to automatically create polygons/features from a georeferenced PDF? I'd like to geo-reference an expanded view of the below linked pdf, and then have each of the tracts created ...
1
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1answer
25 views

Wrong boundary when plotting Canada's shapefile in Python

I want to plot the Canadian shapefile with province boundaries highlighted and hollow filling. I have downloaded the shapefile from here. This is the script I use to visualize the shapefile: ...
2
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2answers
30 views

Postgis meassuring distance between first and third points of a polygon

I am using ST_DumpPoints() function first to get the list of the different points in the polygon but after doing that, the first point is in one record and the third point is in another record and I ...
0
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1answer
24 views

Carto DB city border polygons issue?

I want to visualize some statistical data about my country and I'm using the CartoDB geocoder. I've city names and I want to see cities as polygons but CartoDB says it has no polygon data, it can only ...
2
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1answer
49 views

Make square polygon from one point and area

I have a shapefile of points with a variety of attributes, the relevant ones being "ID", "area", "lat", and "long". Such as... The lat/long coordinates are always the SW corner of a plot and the area ...
1
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1answer
58 views

In QGIS is there a way to make one polygon out of several

I'm trying to use QGIS to get a more simplified vector country data. For example Canada has several bits to the north all as separate polygons where as I'd be happy to just take a rough outline of the ...
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0answers
57 views

Iterating through multiple polygons to produce a table with elevations using DEM?

My question is similar to Iterate through multiple Raster files and compute statistics using Zonal Statistics However, what I want to do is use ModelBuilder to use individual polygons to define the ...
1
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1answer
26 views

Weighted polygon-feature-classes combination/overlay analysis using ArcGIS for Desktop?

I have several (sometimes, not always overlapping) Polygon Feature Classes which are all weighted/ranked through a field from 1 to 10 (10 is best). I would like to combine/overlay these layers them, ...
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3answers
79 views

Erasing small polygons from bigger overlapped polygons using ArcGIS for Desktop?

I have different bigger polygons (buffers) which are overlapped (A,B,C,...) and the inner smaller ones (a,b,c,...). I want to erase smaller ones from bigger ones in the way the results be A-a, B-b, C-...
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0answers
38 views

How to remove circles from new polygons in QGIS? [closed]

I've just started using QGIS (2.6.0-Brighton). Every time I create a new polygon, a circle appears in the center (see below). I thought this might just be a feature of QGIS editing that helps you to ...
1
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0answers
37 views

How to smooth “internal” polygon borders

This is my first foray into GIS and GIS software. I am using ArcMap currently. I have a shapefile of the world divided into different ecological regions. I would like to reduce the file size by ...
1
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1answer
29 views

Using ModelBuilder to create smaller individual DEMs from a large DEM using multiple polygon?

How can I use a polygon (which is made up of smaller polygons) to create individual DEMs from a large DEM using the polygons as the mask/extent? I am trying to do this in ModelBuilder and it isn't ...
1
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1answer
25 views

Can I statistically smooth attributes spatially (using distance/surrounding polygons) in ArcGIS?

I have Census Areas with some of the Census attributes. Is it possible to take an attribute, for example, percentage of people in full time employment, and derive a spatially smoothed version of the ...
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0answers
15 views

ArcMap Feature to Polygon loses z-values on some polygons

I created line features from points containing Z values with the Points to Line tool and then, after some manual clean-up involving connecting some lines properly and merging them, I tried to make ...
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0answers
10 views

Insert a row with the_geom polygon!

I'm a beginner, i'm looking for a sql insert store with item having the the_geom style of polygon. I know the way to insert row with point like that: CDB_LatLng(10.51, 20.51), so can i do the same ...
0
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1answer
25 views

Not all polygons digitize when converted from lines

I have a polyline feature consisting of a grid. I attempted to convert this grid into a polygon using the "Feature to Polygon" geoprocessing tool, and it appears that not all lines have been carried ...
1
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0answers
48 views

Shapefile layer export issue

I am using QGIS to define polygons in a shapefile layer which I am then exporting as an ESRI shapefile for use with JMP. The polygon layer looks correct on-screen in QGIS, but the exported files have ...
0
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0answers
15 views

Arcmap 10.2 (query builder and or Expression)

I want to turn off selected sect_label numbers from showing up on my base map as I have a shapefile with Section and acreage loaded for a specific area and i need to use the shape file because it lets ...
1
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1answer
118 views

Finding all polygons inside of a polygon

How to find all the polygons inside of a polygon? I tried ST_Intersects and ST_Contains but they are booleans variables. I have a list of polygons in WKT format, so I am trying to pull all the ...
4
votes
2answers
58 views

Display multiple identical polygons (with different attributes) on map

I need to create maps of multiple species in a certain area. However sometimes multiple species occurr in the exact same area. This results in two identical polygons on top of each other. Many of ...
0
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1answer
46 views

How to find the distance between neighboring points in ArcGIS 10.3?

I have two shape files: one has point features indicating urban centers, the other is a polygon features file that has counties. Each county has one urban center. There are around 2800 counties. I ...
1
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0answers
29 views

ol3-cesium polygon float

I’m trying to build a webmap using ol3-cesium libraries , when I switch 2d map to 3d map my polygons (geojson or geoserver wms, wfs) are not draped on stk-terrain but they are under the ground. I ...
0
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1answer
26 views

How do I make a grid around all my points, and then convert it to a polygon [duplicate]

I want to make a grid around all my points, convert to a polygon and use this to clip the extent of my data. I am using Arc 10.2. How do I make a grid and then convert it to a polygon? Or is there a ...
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0answers
32 views

R - `rasterize` of polygon fails to properly take account of internal hole

I'm trying to use R to mask out a DEM raster using a polygon (loaded from a GML shape file) using the following code, where dem_modern is the raster and modern_land_shape is the vector polygon : # ...
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2answers
41 views

How to (precisely) re-align a polygon

I have this shapefile and I want to re-align the selected polygon (See image below) to the shapes of the other polygons. I tried using the "edit tool" but it's not producing a good result. What would ...
3
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1answer
34 views

Problems with dividing multipolygons into polygons

I have a shapefile with countries boundaries downloaded from here and I am trying to upload it to PostGIS database with ogr2ogr. This file contains features of polygon and multipolygon types and ...
1
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1answer
39 views

“Hole” argument ignored in call to Polygon function

I am working with a dataset consisting of a list of coordinates for a set of polygons. Some of these polygons are holes. However, the dataset does not follow the convention of listing the coordinates ...
5
votes
1answer
206 views

Generating surfaces of different heights from LIDAR points

I am seeking a way to generate surfaces (polygons in a 3D space) of different heights from LIDAR point clouds, whose spacing is 4 points per square meter. The typical application is like roofs, which ...
4
votes
2answers
65 views

How to Select a Polygon beneath another Polygon in QGIS 2.14

We have a series of layers that contain polygons with additional polygons 'underneath' each polygon. How do we select the polygon beneath the existing feature without also selecting the feature ...
0
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0answers
19 views

Looking for Polygon data on NUTS2 (2013 system) in CSV or Excel?

Looking for Polygon data on NUTS2 (2013 system). Can somebody supply this in CSV or Excel? I have been searching on NUTS2 Polygon data, but unlucky so far. I have found the data but this is in ...
0
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0answers
93 views

Polylines and polygons - QGIS-2.14.3-1

After extracting contour lines from a DEM (obtaining polylines), and transforming them to polygons, I export the vector layer with polygons to a DXF. Then I import the DXF into Corel Draw to manage ...
0
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0answers
24 views

Drawing line and finding bearing using ArcGIS for Desktop?

I need to draw a line from a point within a polygon to the edge of said polygon. I do not need to know the length of the line, only the bearing (in degrees) for the line. We are using ArcMap 10.3.1
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0answers
32 views

Generate points layer at line intersection

I have a line layer that is actually buffer polygons converted to a line layer. I would like to generate points at all places where 3 or more lines intersect. I would settle for places where 2 or more ...
3
votes
2answers
173 views

Creating OUTSIDE_ONLY buffer around polygon using R?

I would like to create buffers in polygons, surrounding my original polygon. However, I want to keep only the "outside polygon", not include also original polygon. In Buffer in ArcGIS I can just set ...
1
vote
1answer
46 views

Colour specific polygons on a postcode map - QGIS

I am working on a UK postcode map. It only has the first bit of the postcode, e.g. BR12. I have an excel spreadsheet with the longitude/latitude of specific points as well as their postcodes. Instead ...
1
vote
1answer
33 views

Combining Data from raster and polygon

I am teaching myself GIS at the moment, and there are still some matters I haven't quite got the hang of. I'm using ArcGIS 10.1, and have three datasets: LAYER 1: A population dataset at a high ...
0
votes
1answer
45 views

ST_Union or ST_Collect on PostgreSQL union result?

Newbie to PostGIS/Postgres. I have the follow query which returns me 2 GEOMETRYCOLLECTIONS. Is there a way within my current query to return one polygon? SELECT ST_AsText(ST_Collect(ST_Simplify(geom,....
1
vote
0answers
31 views

QGIS - convert multiple polygons to evenly spaced points within polygon boundary

I need to convert the polygons in a vector layer to evenly spaced points within the polygon boundaries in QGIS. The vector file contains >1000 polygons mostly with overlaps. The attribute data of ...
1
vote
2answers
78 views

Calculating relative share of area covered by water/percentage of polygon area that overlaps in ArcGIS for Desktop?

I need to calculate the share of the area within a 50km radius of major German city centers that is covered by water with either Arcmap 10.3.1 or Qgis 2.14. My plan is to use the Global Lakes and ...
1
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0answers
56 views

Creating voronoi polygons from polygons?

I have a database with buildings and for some further analysis I need to: aggregate adjacent buildings (preferably without losing the height attribute, but I can work my way around that) once I have ...
1
vote
0answers
49 views

Algorithm to simplify a Polygon/Series of Points to a given number of Points

I have a polygon (or let's call it just a series of points). I want to simplify it (reduce the amount of points) to a given number of points. Currently I use Douglas Peucker and try to guess the ...
1
vote
1answer
38 views

QGIS 2.81. Why can i only see my whole polygon and nothing if i zoom in

I have a polygon layer with one object. It is a flood inundation map. I could see my layer all the time in every scale factor. From one moment to the other it changed and know it is only visible if i ...
3
votes
1answer
78 views

How can I merge two adjacent polygons which borders are not touching each other

I want to merge adjacent single polygons which are apart from each other. Important note: I cannot use ArcGIS, I need to do this programatically, in any language (R, Python, Ruby, PostGIS) doesn't ...
0
votes
0answers
61 views

How can I fix Russian border polygon?

is there easy way to fix Russian border polygon in CartoDB? The polygon is given by CartoDB. From the picture you can see that the polygon covers also Estonian territory. But I need to make there (on ...
1
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0answers
19 views

QGIS-I have 37 polygons, can I bulk create 2 other sets of 37 that are 1 px larger all the way round and 1px smaller

I have 37 polygons covering a Lakes spatial extent at a particular point in time. I need to bulk create 2 sets of polygons. One 1 px larger all the way around and one 1px smaller to calculate the area ...
1
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2answers
70 views

How can I build a grid of equal square polygons in ArcGIS 10?

Not having them depend on decimal degrees, but on a certain distance. When I use a tool it asks me the length of the cell in degrees, but I want all sides of every cell to be equal and with degrees ...
1
vote
1answer
26 views

How to auto Correct Polygons that are not drawn correctly?

I was part of a project recently where handheld GPSs were used to collect vertices of parcels. After plotting the points using 'P2One' plugin in QGIS I found out that some of the polygons were twisted ...
2
votes
1answer
56 views

Getting polygons out of multi-polygon GeoJSON files?

I am a farmer and very new to GIS. I am trying to load shapefiles or KML files to an online site/service called FarmLogs.com. Once my "fields" are uploaded the site can tell me the amount of ...
3
votes
0answers
68 views

Find Distance Between Two Polygons

Given two polygons (point, line, or up to 8 vertices) I need to be able to calculate the shortest distance between them via code I write or a call to an API (I haven't been able to find one that does ...
7
votes
2answers
169 views

How to calculate how many polygons I can put inside a polygon?

I usually use qgis. I explain my problem with an example: there is a forest (irregular geometry1 ) and one tree (geomery2). I want to know the maximum number of trees that the forest can contain. ...