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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2
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1answer
95 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 ...
7
votes
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
votes
1answer
54 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 ...
0
votes
0answers
41 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 ...
0
votes
0answers
29 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 ...
1
vote
1answer
31 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 ...
2
votes
1answer
80 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 ...
1
vote
2answers
74 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 ...
1
vote
1answer
26 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
52 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
vote
1answer
51 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 ...
0
votes
1answer
15 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
148 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 | ...
0
votes
0answers
34 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
votes
0answers
32 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
41 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
votes
0answers
28 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 ...
0
votes
0answers
18 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
44 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, ...
0
votes
2answers
60 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 <- ...
2
votes
0answers
17 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 ...
0
votes
0answers
50 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
59 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
45 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
43 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 ...
0
votes
0answers
47 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
36 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 ...
1
vote
0answers
43 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
395 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
vote
0answers
50 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 ...
0
votes
1answer
38 views

Unexpected results when using ST_Intersection for polygon features

I've to create a spatial intersection of two tables (poly_a and poly_b) containing polygon features. Is there any way to remove unexpected linestring results? CREATE VIEW poly_intersection AS SELECT ...
1
vote
3answers
107 views

Creating line from point based on intersecting line at 90 degrees to line in ArcMap?

I am using ArcMap 10.2/10.3 and I need to create lines from points, so I can split polygons at the created line, as per the image below. So I have to cut the polygon at a 90 degree angle to the line ...
2
votes
1answer
60 views

2D polygons with height attribute to 3D features for ArcGIS Online

I have a 2D shapefile made of many polygons representing buildings. Each polygon has a height attribute. The goal is to get these into ArcGIS Online's "Scene" feature, showing extruded buildings, ...
4
votes
4answers
71 views

How to change feature draw order in QGIS?

Probably a very basic question here, I want to change the draw order of a shapefile in qgis, how can this be done? As you can see in the picture below, only the "10" layer is shown, but since this ...
2
votes
3answers
54 views

How do I create random points only within a multi-part polygon and none outside?

I am currently using a shapefile consisting of an area smaller than the entire study boundary ie. I want this to to be my overall study area. I used a raster to polygon tool and converted it to a ...
3
votes
3answers
126 views

Where to find a polygon shapefile of countries, states and islands?

As often happens, the hardest part of GIS is to come up with clean shapefile with an attribute table. I need to create a choropleth map, but all I have is this: Domicile,Captives New Zealand,24 ...
1
vote
1answer
41 views

Applying Snap_edit to polygon Geometry Object

I have a project where I am modifying over 1 million polygons (representing tracts of land) to make them line up with the PLSS land grid. My process works (mostly) by cutting up polygons based on a ...
1
vote
0answers
26 views

How to assign a grid of point data to corresponding grid of polygons

I'm using QGIS 2/12.3 I have a point layer with modelled data on a 1km grid, each point has a value (0-5, modelling temperatures) and lies at the centre point of a 1km grid square. I also have a ...
1
vote
1answer
21 views

Vector to raster conversion: Gaps within the vector boundary

Is there a tool in ArcGIS that will make the output raster completely encompass the vector boundary? Somewhat similar to select by attributes where all overlapping features however minuscule is added ...
1
vote
1answer
159 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 ...
0
votes
1answer
68 views

Open Layers: Get Coordinates of drawn features

Can someone help in finding coordinates of drawn features? I am using this example OpenLayers website. I need to be able to export drawn objects as set of coordinates. Posting the code from the ...
0
votes
2answers
25 views

Keeping attribute table when converting from polygon-based feature layer to grid layer

I am trying to transfer (or extract) attribute data from a polygon-feature class to point data. I can do this for a grid file using the Spatial Analyst-Extraction-Extract multi-values to points ...
4
votes
1answer
67 views

Altering elevation of specific cells in raster layer of QGIS?

I'm looking to alter the height of some cells within a raster and it's been suggested that I do this by creating a polygon layer and use that as a mask to alter only the heights of cells within the ...
1
vote
1answer
27 views

transformations from a sphere using R for raster and polygon data [duplicate]

I am planning on using the MODIS burned area products which were produced by Maryland University. These come as either polygons or rasters. In the user guide it says A shapefile version of the MCD45 ...
2
votes
1answer
36 views

How can I split a polygon by network line in QGIS?

I have a road network as line layer and a land cover as polygon layer, I want to find number of subpolygon for each polygon that divided by line layer in QGIS? I used union function in Geoprocessing ...
0
votes
0answers
28 views

Adding custom vertices to a Leftlet LineString / Polyline

I have a normal Leaflet Draw page here, when I'm not in editing mode I would like to have custom vertex icon in some of the vertices that will also respond to click events, showing a popup. I looked ...
1
vote
1answer
35 views

Highlighting selected polygon features without filling colors in QGIS while editing?

When editing in QGIS, how can I highlight the selected polygon features without filling them with colors i.e. just outline the polygon boundary?
2
votes
1answer
51 views

Create frequency polygon from overlapping features in another polygon

Mac 10.9.5; QGIS 2.8.4-Wien; history and unioned data, in GDA94, zone 55 here. I have a polygon of fire history with a number of overlapping features. I want to create a new polygon for fire ...
2
votes
1answer
17 views

WFS Filter performed before or after reprojection?

I'm trying to perform a WFS filter with a polygon in EPSG:3031, (the native projection is EPSG:4326 I think). And I'm aware that WFS/GeoServer supports reprojection on the fly. But will the features ...
4
votes
1answer
32 views

How to extract a buffer layer from a vast amount of individual buffers around polygons using ArcMap?

I have a vector layer containing nearly 8000 singlepart polygons. It looks like this: I want statistics on the area that is further than 2,5m away from any border. I thought I could do this by ...