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
19 views

Applying the attributes of polygons to a line segment

I am trying to classify a line segment (pipeline) based off of surrounding features. I have created polygons that contain the necessary attributes (count of total nearby houses) that overlap this ...
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0answers
13 views

Converting polygons to contours based on value in polygon table

I have the following and data and have been asked for a map that shows the same data set but displayed as contours. Each polygon has a value in it's table called "count". The "count" field is used to ...
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1answer
55 views

JTS: split arbitrary polygon by a line

I just discovered JTS through this stack exchange. I'm looking for a Java solution to cut an abitrary polygon into two by a line. I've implemented one that does fine on convex polygons, but it messes ...
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1answer
32 views

Convert KML polygons to lines

I've been given a KML file which should consist of linear features (train lines), but for some reason they're all represented as <Polygon> types. Each appears to have the right data, from end of ...
5
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0answers
57 views

How to decide the master part when you cut a multipart polygon? [closed]

I am splitting parts of a multipart polygon in an ArcMap edit session using the cut polygon tool. Is there any way to decide which is the part that will remain multipart and which is the part that ...
3
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2answers
77 views

How to get lines into polygons?

I have to create a map with the land register of a place. The data that I already have is unfortunately built out of lines and not polygons. Is there a possibility to create polygons? I already ...
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1answer
26 views

Replacing each point in a point feature with a specific shaped polygon

I have many random points in one layer. I want to replace each individual point with a specific shaped polygon like the image below illustrates. Kind of like applying some sort of irregular buffer to ...
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0answers
20 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, ...
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1answer
45 views

How can I subtract one (very very large) set of features from another?

I'm trying to subtract a very large set of features (water areas) from another, relatively small set of features (land area). In principle, I should be able to do this in QGIS using Vector > ...
5
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1answer
151 views

Adding new nodes in the middle of each líne of a Polygon

I am currently working on a Street Lighting Network. I have two layers in PostGIS ( PostGIS 2.1.3 and PostgreSQL 9.3.5): Manholes (56.000 Polygon) Pipes (Linestring) The manholes are perfect ...
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1answer
39 views

Convert this CSV to a qgis usable format

I have been given a CSV (which has been converted from a RDF). I want to convert the CSV file to a usable format so that I can display these polygons in QGIS. The original file and some other ...
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0answers
32 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 ...
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1answer
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
107 views

How can i convert the coordinates (latitude,longitude) to X,Y using postgis

I want know how i can convert the latitude and the longitude coordinates of a rectangle in the Cartesian coordinates, so I can store them in a geometry field using postgis.
2
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0answers
51 views

QGIS : How to calculate centroid on polygons with holes

I try to compute the centroid of polygons with holes on qgis. I did not manage to do it directly, I had to make a conversion to convex hulls before extraction. I crashed my pgsql server trying to ...
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0answers
29 views

Using the extract function in raster package for R with polygons

I have a shape file that contains some polygons and an unprojected raster. I'd like to extract the cells within the polygons using R, so I use code like this: # Load my polygons MyPoly <- ...
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1answer
48 views

How to find the area with most intersection for buffer regions?

Find the area with the most intersection This question relates to previous question asked - How to find the intersection areas of overlapping buffer zones in single shapefile?. I tried to find ...
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0answers
52 views

Leaflet self-intersecting polygons display

Is it possible to set colors of the actual intersections of self-intersecting polygons in Leaflet? Example of such self-intersetions can be found on the pic below, the transparent triangles inside of ...
3
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1answer
28 views

How to obtain attributes of a point layer that falls within a polygon layer of different CRS

I have created my own vector grid polygons in QGIS 2.12.2. This creates a new layer to my project, but it's projected in a "generated projection". I want to view the attributes of points that fall ...
2
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1answer
85 views

Using Chaiken Method parameters for smoothing polygon vectors in QGIS [duplicate]

I've been trying to smooth a huge polygon, that is result of a segmentation export. I'd like to know what's the best parameters to use Chaiken Method to get smooth curved boundaries on QGIS 2.14. I ...
2
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1answer
166 views

How to find the intersection areas of overlapping buffer zones in single shapefile?

Find the intersections of the buffer zones I found an example where they tried finding the intersection of two different shapefiles -Intersect Shapefiles using Shapely. I've tried to adapt my code to ...
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3answers
1k views

Is there a way to “invert” Polygons?

I have a Shapefile with Polygon features representing the world's land areas (continents, islands). Is it possible to invert these, and get a geometry that represents the world's oceans and seas? So ...
0
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1answer
63 views

Python Calculate Cumulative Polygon Areas (Basins)

I've been asked to automate the calculation of cumulative polygon areas within a basins shapefile. The calculation will take the area of the upstream basin and add it to the area of the downstream ...
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0answers
47 views

How to scale polygon to obtain specific area in javascript?

I have got a source polygon (saved as standard js array). I want to scale it down to obtain new destination polygon in the centre with 1/3 of source area. On the cartesian space i just scaling down ...
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0answers
31 views

Clipping algorithm that can make one layer with no overlapping polygons from N polygons

I am looking for an algorithm description / pseudo code for an algorithm that can take N simple polygons and return a new set of polygons that all have been clipped such that there is no overlap in ...
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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'...
2
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1answer
103 views

Creating shapefile from polygon points for CartoDB?

I have an Excel file that contains polygon coordinates for different areas. The spreadsheet has three columns: latitude, longitude and area name. Each coordinate makes of a part of the boundary of a ...
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2answers
93 views

problem combining geometries from all features in a layer as one geometry

I am trying to combine all features of a Polygon layer in QGIS in a python plugin, and am running into this error when I try to run the combine method: "AttributeError: 'NoneType' object has no ...
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1answer
32 views

How do you create a rainbow polygon hover effect in Mapbox?

We're working on a fun website called VicePrice. It's a happy hour website using GIS instead of a list directory to show happy hour info. We've run into a snag and perhaps someone could give us their ...
2
votes
1answer
63 views

Polygons between contour lines in QGIS?

I am trying to create polygons between contour polylines within a defined area (for which i have both polygon and polyline shps) but I seem to be thwarted at every turn. Using QGIS 2.14, I am sure it ...
1
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1answer
68 views

Does QGIS have an autocomplete polygon option like the one in ArcGIS?

I am trying to do digitizing in QGIS, but I do not see an option that I have seen in ArcGIS - autocomplete polygon. I would like to make two adjacent polygons topologically correct, and can not find ...
1
vote
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?
2
votes
2answers
153 views

points within a polygon

Since I am a beginner to postgis I am facing problem with finding points within polygons from my table. This is my table structure Column | Type | -------------+------------...
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0answers
48 views

NDVI polygon from NDVI raster

I am currently working with NDVI data. I found this format which seems to be preferred by our clients: Our maps are made in ArcGIS, I've tried running classification but classes won't allow me to ...
0
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0answers
37 views

Comparison of polygon geometry of 2 layers (ArcEditor)

I´m facing the following Issue: I´m trying to find changes between 2 continuous polygon layers. Polygons that need to be compared dont have matching IDs - to explain, I have polygon X and polygon Y ...
3
votes
1answer
49 views

polygon split with predefined area

I am trying to split an irregular polygon into 120 equal area blocks. I also need a buffer around each new block within the polygon. Is this possible in QGIS 2.12.1?
0
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0answers
31 views

Feature Layer parameter showing only Polygon Shapefiles

I have created a Python Tool in ArcGIS where most of the paramaters musts be ONLY Polygon Shapefiles. You can also look on my previous question: Filter the Feature Layer parameter in Python Script ...
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0answers
21 views

How to make match two same rasters after conversion "Polygon to Raster?

I am trying to convert two .shp files of polygons of same buildings but with different layers of values into raster. When I do conversion from polygons to raster it always generates bit different ...
4
votes
1answer
48 views

Find polygons that does not contain (any) polygons with PostGIS

New to PostGIS, I have a polygon layer of water catchment areas which are formed by the specific monitoring points along the river upstream. For example, on one river, there could be multiple areas, ...
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2answers
90 views

Remove lines from inside a polygon (shapefile) in r

I have this code which prints the Galápagos Islands. But inside the islands, there are lines that I want to get rid off. How is this possible in R? library(rgdal) library(ggplot2) URL <- "https:/...
2
votes
0answers
18 views

layer styling switches after zooming in with no reason

Does anybody have an explanation how it is possible? I have a strange trouble on the following map. The surrounding land layer, which is only a one polygon layer and is styled normally like: var ...
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0answers
53 views

Dividing a shape in equal pieces?

I have data in Autocad. As you can see there's a buffer (purple) inside of the blue shape, I want to divide the blue shape to small equal pieces that have the same surface area. What I'm looking for ...
4
votes
1answer
60 views

Reshape polygon to boundary of other polygon

I have two polygons. The first one has a white background and brown boundary. To othr has the pink background. how is it possible to reshape to first polygon to the boundary of the other polygon?
1
vote
1answer
55 views

Joining multiple polygons inside a single polygon in QGIS

I need to somehow "join" information from two shape files: zoning - these are large polygons indicating the zoning code for a moderately large area, typically hundreds of separately owned parcels (...
2
votes
1answer
44 views

Grid with data table attached to each polygon

I'm trying to wrap my head around a request a colleague gave for some data visualization. She is performing field observations and for every observation, she is assigning a grid # that corresponds ...
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0answers
61 views

Showing city border in Google Maps using OSM data

What I want is a border like in Google Maps: In my solution, i use the overpass-turbo service to get all long/lat for a city. All works fine! But sometimes, borders will be rendered not correct. I ...
2
votes
0answers
46 views

How can I create a grid of polygons from a .csv file or line vector in qgis?

I have a map defined by two seperate reference systems: one is a standard grid coordinate system, the other a series of irregualar polygons. I want to find which polygon each grid square overlays, and ...
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0answers
44 views

What to do with polygons that were created from a raster file? [closed]

I need some suggestions. I'm working in Arcmap 10.3. I used a NDVI landsat product to find patches of row crops. I then extracted these cells and turned them into shapefiles. I want to measure the ...
8
votes
1answer
409 views

How to smooth adjacent polygons?

I want to smooth polygons which share a common boundary. How can I smooth them so that the shared boundaries stay shared? I'm using Arcgis 10.3
1
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0answers
51 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 ...