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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35 views

Do we have a way to change the colors of the polygons directly in JOSM?

Do we have a way to change directly the colors of the polygons in JOSM?
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1answer
32 views

Shapefile with point or polygon

I'm just beginning with SIG and QGIS. I've been given two shapefiles with cities. One shapefile appears like point shapefile in QGIS, the other like polygon shapefile. The problem is that the polygons'...
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1answer
17 views

Shapefile of South Tyneside borough (north-east England) boundary

I'm looking for a free-to-download shapefile (polygons) of South Tyneside borough. South Tyneside is a metropolitan borough in NE England. Can anyone help?
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1answer
453 views

Is it possible to use Leaflet.draw on a map in R?

I want to develop an application where a user can draw a line, polygon etc... I currently develop with R and leaflet package and I found that it is possible to work with Leaflet.draw under JavaScript....
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1answer
115 views

Merge polygons in the same shape file based on attributes, ArcGIS or ArcPy

I have a shapefile of polygons. I do not want any polygons with an area less than 25. For polygons with an area less than 25 I want to merge them with another polygon with an area greater than 25 that ...
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1answer
39 views

Is there any site where I can found city shapes in postgreSQL polygon format

Is there any site where I can found city polygon area (for postgreSQL or similar)? I don't know if such resources exists, and I don't know how to find it.
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2answers
60 views

Clipping a SpatialPoygonsDataFrame to another SpatialPolygonsDataFrame

How do I restrict a SpatialPolygonsDataFrame so that none of the polygons lie outside of an "underlying" SpatialPolygonsDataFrame? The application I have in mind involves Voronoi Polygons a la Carson ...
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1answer
118 views

Clipping raster in PostgreSQL?

I want to clip raster (SRID 32649) with polygon(SRID 4326) into SRID 32648 First I transform raster using query create view ras68 as select st_transform(rast,32648) as rast from ras69 Then cutting ...
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2answers
147 views

What algorithm allows me to calculate the set of all points inside a polygon?

Imagine I have a polygon, which represents the countours of a building on an integer 3D map (everything is a 1 meter by 1 meter block in that map). In the image below, you see several buildings ...
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1answer
96 views

What does double digitized polygon mean?

I know what is a polygon but when a polygon is said to be double digitized? I failed to find a suitable meaning of double digitized after googling. I understand double digitized means digitized twice,...
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1answer
140 views

Cut line with polygons?

How do I cut a single line with polygons (in several segments) so that each cut line take data from the polygons? Something like a centroid takes.
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2answers
848 views

Create Editable Layer ArcMap 10.2 Desktop

In ArcMap 10.2 for desktop, I wish to create an editable layer to add a simple shape to. As of right now, I have a basemap layer and my selected basemap. However, since the basemap layer is not ...
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2answers
78 views

How can I move a set of polygons in ArcGIS Pro? [closed]

I am very new to mapping and I have loaded a set polygons from a shapefile into ArcGIS Pro. They appear correctly however they have clearly lost (or didn't have in the first place), their longitudinal ...
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1answer
46 views

want to make all poygons have z values as 0

I have polygons which stores different z values as vertices in Arcgis. I want that all z values must be equal to zero. How can I make this possible??
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1answer
149 views

Performance Improvement of Postgres vs PostGIS

I am trying to run the following query thousands of times per second to determine which is any polygon contains the passed in point. SELECT * from areas WHERE poly @> ? Poly is the name of the ...
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2answers
193 views

Maximum distance to polygon edge

I have a point feature class and a polygon feature class, and each point is located within one polygon. Is there a way to programmatically calculate the distance from each point to the farthest ...
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1answer
304 views

Remove lines from inside a polygon in QGIS

Through a "dissolve" process in QGIS, I achieved some polygons that have some fails, like this one in the screeshot: Is there any automatic process I can make in QGIS to remove those lines inside ...
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1answer
78 views

Edit raster classification manually using polygons - ArcMap

I want to edit the elevation/z values of certain zones on a raster in ArcMap. I followed this example by creating a polygon, assigning a value of 7.5, then converting the polygon to a raster, finally ...
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1answer
146 views

FeatureToPolygon (to cut polygons by line) not working correctly outside of ArcGIS

I asked a question yesterday, about splitting polygons using a line, and I ended up using the approach that is described in the comments here. Although this worked with my test data, it causes a lot ...
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1answer
183 views

How to get the coordinates inside the polygon using python

I have a polygon and using this code snippet we can get the coordinates boundary of the polygon. canvas = qgis.utils.iface.mapCanvas() aLayer = canvas.currentLayer() coord = feat.geometry().asPoygon()...
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1answer
175 views

ST_Intersection for polygons

I'm looking for a query that returns overlapping areas of two tables with polygon geometries. Using row_number() over() the entries of the gid column are not unique in the case of dumped multipolygons....
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1answer
194 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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2answers
46 views

add polygon to layer from text file [closed]

I am completely new to Qgis and to gis in general. I have start to work my way through the documentation but have a question that I can not find a answer to. When looking into the documentation ...
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1answer
133 views

Connecting polygon accidentally deleted - filling in the gap

New QGIS user, Brighton 2.6. I accidentally deleted an elongated (lots of "peninsulas" polygon that represents a stream-based habitat - two gaps on SW boundary and two on the northern boundary (...
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1answer
81 views

Is there any way to know if a polygon is part of another bigger polygon(s) in SQL server?

Basicaly, what I am trying to do is we have a lot of geographical containers like territories, sub-territories etc. and the boundaries of each keep on changing all the times and I have to store the ...
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1answer
1k views

Overlapping polygons in the same layer

I am working in QGIS on a vector layer where areas are classified using an attribute "typo". The problem I'm encountering is that many polygons are duplicated or overlapping, with the result that some ...
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2answers
231 views

How to separate polygons within layer and measure line through each polygon?

I have 3 layers of polygons, each layer with multiple polygons spatially separated, although the layer only counts it as 1 polygon. I have a layer with a line going through these polygons. What is ...
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1answer
196 views

Cover a polygon with fixed size squares

Can you please advice me of an algorithm (which I can implement in a Java) to cover some polygon (not exact cover) with squares of certain size (aXa squares)? The cover doesn't have to be exact - ...
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1answer
288 views

How to clear areas outside map in R

I succeeded thanks to the eblonde in the disscution (problem with polygon smoothing in R) to smoothing polygons in R. Code: inter1= read.table("c:/inter2.csv", header=TRUE) #add a category (...
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1answer
109 views

Looking for information on methods or algorithms used to calculate centroid from polygons across software

Looking for information on methods or algorithms used to calculate point centroids from polygons across software. ArcGIS uses a "gravity model" but can someone point me to the math or a paper on the ...
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1answer
131 views

Converting rasters to polygons through cell centers

With arcgis, it is possible to convert a raster image to a polygon representing the boundary of the raster using the Raster To Polygon tool. The output polygon will follow the cell edges of the ...
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1answer
151 views

Snapping with polgon drawing

I am drawing a polygon with the drawing function within ArcGIS 10.1. Is there a way to snap orthographically at 90 degrees while using the polygon draw command. I added a picture of what i would ...
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2answers
459 views

QGIS Convert Polygon M to polygon

I have been using Argis 10.1 and been able to convert polygon m to polygon shapefiles. I would like to do this with QGIS but I am having difficulty in finding the correct tool to do so. Please Help
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1answer
265 views

Calculating distance of polygons from coastline using ArcGIS for Desktop?

I have a series of polygons representing parcels of land. I would like to calculate the distance of each polygon from the coastline. I also have a polygon of the entire region of interest, i.e. an ...
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1answer
166 views

How to compare multiple spatial point patterns over a polygon

I have multiple point pattern distributions over the same region/polygon. Each point pattern distribution has different number of points. Here is an example of two spatial point patterns for the ...
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1answer
617 views

Intersect between polygonal shapefiles error

I'm encountering a problem when I try to intersect two different shapefiles. They are all new shapefiles I created to descibe the land cover and the land use of a city. The problem occurs when I ...
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1answer
602 views

How to limit Create Fishnet extent by mask & carry over attributes?

I have a 5km polygon grid of an area which is not a standard square/rectangle, it is in fact a rough ovoid made up of around 500 5km2 cells. What I want to do, eventually, is have a 100m polygon ...
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1answer
1k views

How to go with…somewhat complex geological maps in QGIS?

Just a follow-up to this question QGIS: Line to polygon conversion. Not sure do i have to continue there itself... We are currently digitizing a geological map...which has 36 features in total. Some ...
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1answer
569 views

Eliminate 0 Values From Raster

Arcgis 10.2 I currently have a raster file that I want to turn into a set of polygons. This will help me to create specific buffers around certain points. The extent of my values are 0, and 1. When I ...
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1answer
401 views

How to generate random GeoJSON polygons (latitude, longitude)

I am looking how to generate polygons in GeoJSON format with random locations (latitude, longitude), if I generate totally random set of points it will not produce valid polygons. So my question is ...
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1answer
166 views

How do I add coordinates to a polygon layer to be able to sort the polygons from north to south in QGIS?

I have a polygon file, where each polygon represents one property. I want to be able to sort the polygons from north to south or vice versa. I need them to be sorted in this way when I export them to ...
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2answers
1k views

How to change raster cell values within a polygon using QGIS GUI?

I would like to know how to change the values of raster cells which are within a polygon, leaving all cell values outside the polygon unchanged. I would like to subtract 1.5m from each raster cell ...
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1answer
152 views

draw multipart polygon with one surrounding border

As you can see on the image below, the waterbody is divided by the border line because it consists of several polygons. I could merge the polygon, but I dont want to change the shapefile. Is there ...
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2answers
336 views

How to extract common outline of multiple polygons with code?

I'm not really asking for a chunk of code to do this, but more of an algorithm I can work with myself. For example, this is the state of Maine, obviously, and I have the points of each county ...
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2answers
483 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. ...
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3answers
942 views

“Identity” overlay in QGIS?

I have two polygon layers I'd like to overlay using QGIS or another open source tool. What I want as output is a polygon layer with the extent of one polygon, but with each polygon in that layer ...
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1answer
704 views

JTS Polygon simplification without holes

I have a set of polygons without holes. I wish to merge any intersecting polygons. I don't want to have any holes in my simplified polygons. Is there a recommended way to achieve this using JTS? The (...
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1answer
2k views

Get Features from OpenLayers Layer.Vector not working

polygon_layer = new OpenLayers.Layer.Vector("Polygone", { projection : projLonLat, strategies : [ new OpenLayers.Strategy.Fixed() ], protocol : new OpenLayers....
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1answer
195 views

How to count number of stores per company per region?

I have two layers. One point layer and a Polygon layer. It is simple to count the points in the polygon layer by the "points in polygon" function. But I also need some more information of the point ...
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1answer
2k views

How do I write a MYSQL spatial query to find all polygons (rectangle) that contain any points in a table?

Something like: SELECT * from polygons WHERE bounds CONTAINS(SELECT geom_point from points) Can someone help me out with the syntax? Bounds will always be a rectangular polygon and everything is in ...