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
votes
1answer
117 views

Separate a polygon in different polygons depending of the distance to another polygon

I have a reference polygon "R", and others polygons (in grey). I want to separate each grey polygon in multiple polygons, depending on the distance to R with different Buffers : - The red line is R ...
2
votes
0answers
16 views

CartoCSS: Don't show border between adjacent polygons

In OSM, riverbeds are created as multiple adjacent or even overlapping polygons. When styling these polygons in CartoCSS with a border, the overlapping can be seen: I'd like to hide that line ...
-1
votes
1answer
38 views

How do I get the Coordinates of a shapefile into .csv [closed]

I have followed all the instructions on this site, but my output always shows Area, and Perimeter of each polygon. Am I missing something? Should I be changing a setting somewhere to select ...
0
votes
1answer
180 views

CartoDB.js - Accessing table fields in hover function

I am new to CartoDB.js and javascript in general, and I am attempting to highlight polygons in response to a mouse hover. My plan of attack attempts to utilize one of the interesting templates ...
-2
votes
0answers
42 views

Find the Nearest Point to a Polygon [duplicate]

I've got a set of polygons representing counties in a state, downloaded from TIGER/Census. I've got a set of points for a fictional chain store - some counties have a location, some have several, and ...
1
vote
1answer
44 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 ...
1
vote
1answer
30 views

XY data in sketch properties

Does anyone know if there is a way to export the xy data from sketch properties in the editor to a .txt file?
3
votes
1answer
50 views

Changing raster cells values inside of a polygon to the closest cells just outside the polygon!

I have been wrestling with this for a while and couldn't find out how I can do this. I want each cell of a raster inside of a polygon boundary to have the value of the closest cell just outside of the ...
1
vote
2answers
140 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 ...
1
vote
1answer
34 views

Calculating percentage of polygons within specific areas using ArcGIS for Desktop? [closed]

I have a parcel layer and I am trying to determine the percentage of each parcel that falls within specific zones. I tried tabular intersect but it just returned an empty output. I'm using ArcGIS ...
0
votes
1answer
36 views

Millions of polygons: displaying layers in Leaflet based on location being viewed?

I'm trying to create a map of all parcels in a state. In my state, this is several million parcels. In their current format, they are encoded as topojson and divided up by county. I'd like to show ...
1
vote
1answer
150 views

How to construct a line from points in pyshp?

I am reading a shapefile for a pipeline and what I've noticed is that if I just draw a line from one point to the next (in the order I read them), there will be points where the line terminates, and ...
1
vote
2answers
905 views

Dividing polygon with another polygon? [closed]

I am working in ArcMap 10. I am trying to divide a polygon with another polygon. I don´t want to clip any part away, but only to divide the polygon? The polygons are stored in two different layers. ...
0
votes
0answers
129 views

Add labels for printed map (GeoTools)

I have some problems with labels for printing map with GeoTools. Next code (with some cuts, code on Scala language) can help me for printing map: val map = new MapContent() val parser = new ...
2
votes
3answers
161 views

Convert surveyor's calls in excel table to polygon shapefile

Do you know of a way to take surveyor's calls from an excel file (for example: N35-45-15W 60.0 ft, etc) and have them generate polygon shapefiles point by point in GIS? I know you can easily do this ...
0
votes
1answer
34 views

converting random point order into polygons

We received a kml file with polygons but the points are not in a logical sequence and we end up with strange overlapping shapes that are supposed to be an open polygon. We did identify a point near ...
0
votes
1answer
61 views

Find polygons that contain a specific number of points

I want to make a polygon selection based on a specific number of points. For example, I want to select those polygons that contain more than 30 points. I don't want to select every polygon that ...
1
vote
1answer
51 views

Step-by-step: How do I extract Raster values from Polygon overlay with Q-GIS or R?

I am writing my master thesis at the moment and am having the exact same problem as user Curley in this question: I first need to overlay a Corine 2006 raster with a polygon layer (2638 polygons). ...
0
votes
1answer
48 views

How to calculate point from lat/long, angle, and distance? [duplicate]

I am trying to calculate the point from a given lat/long, a bearing, and a distance. This is for plotting weather given a aeronautical way point. For example: Given a waypoint with a known ...
1
vote
2answers
119 views

adjusting polygons to boundary and filling holes

here's the problem: Where: 1: department boundary 3: polygons inside department boundary that "touch" the department boundary(1). They are not necesary fitting well inside 2: holes between 1 and ...
2
votes
1answer
57 views

What methods exist for geohash of polygon?

GeoHash is an excellent method to code the latitude and longitude of a point into a string. It's concise, due to the use of numbers + letters, and the precision can be tuned adding characters at the ...
1
vote
1answer
49 views

PostGIS: Update child geometries based on parent

I'm using Leaflet and postgis in a case where using Leaflet draw plugin I draw a polygon first like this Now, I draw a line which cuts the polygon and using line and polygon geometry, based on ...
2
votes
2answers
324 views

Iterating polygons on a SpatialPolygonsDataFrame in R with readWKT

I have fetched some data (39 objects) from my PostGIS database and converted this data into a matrix: rs <- dbSendQuery(con, "SELECT ST_AsText(polygon_accumulation) AS ShapeWKT from ...
3
votes
1answer
284 views

How to make survey lines within polygon?

I am trying to figure out how to make survey lines within a polygon. So first I make a polygon. Now I need to fill this polygon with lines, where I can choose the spacing between the lines, and the ...
0
votes
0answers
17 views

Created polygon appears to move when zooming in (qgis)? [duplicate]

I am using QGIS 2.20 on a Windows 8.1 64-bit laptop. I have a shapefile that includes a polygon that I created from digitizing a Google Satellite image from OpenLayers Plugin. Here is my problem: ...
0
votes
2answers
435 views

How to get a list of OSM relations (id numbers) of cities and countries only?

I want to get OSM polygon shapes (GEOJson or WKT) of countries and cities only. I know that it is called a "relation" in OSM and each relation has its own id (New York is 175905, for example). How may ...
3
votes
1answer
48 views

Is there an alternative to the Integrate tool that will not change one of the inputs

I have two polygon layers, and would like to snap the outlines of one of them (colored poly's) to the other (grey) without changing the grey in anyway (so Integrate seems out). It should only snap if ...
1
vote
0answers
17 views

Reclassify based in neighbour polygons

I would like to do a simple operation in QGIS and I am not sure about which is the best option. I have a polygon shapefile and each one has one class attached. I want to reclassify one of them based ...
0
votes
1answer
34 views

Extracting info on polygons from underlaying raster layers

In ArcGIS 10.1, I have two layers: 1) raster of Topographic Wetness Index 2) vector layer of polygons representing soil types I am wondering how to accomplish what I am after, that is to get ...
2
votes
4answers
223 views

UK Postcode boundaries [duplicate]

Before I go and pay is there a free source for UK Postcode Boundaries, ideally down to Postcode Sector level ("AA00 0" or even better "AA00 0A")? Failing that can I generate them in QGIS if I have ...
1
vote
1answer
42 views

Smoothly interpolating Polygons from set of coordinates?

I'm still quite new to QGIS and I'm using it to display and analyze my soil data. I have point information on the distribution of the soils in a specific area and I need to create a soil map from ...
0
votes
0answers
14 views

Create indicator for inclusion/exclusion from polygon based on coordinates, and reverse

I've got a database with 570,000 or so addresses, and what is purported to be their associated Lon/Lat coordinates. However, when I compare a simple scatter plot of these to the shape of a polygon ...
3
votes
2answers
63 views

“Levelling” elevation data coinciding with polygon?

I have a shapefile containing building geometries (polygons) and a elevation dataset. The elevation data doesn't perfectly match the buildings. I want to "flatten" the elevation data so that ...
6
votes
1answer
60 views

Suitable algorithms for simplifying isochrone polygons

I'm looking for an algorithm for simplifying isochrones which were generated using OSM data. These are generally characterised as having lots of small "holes" mostly due to missing OSM data but also ...
3
votes
1answer
83 views

Postgis 2.0 geographic polygon has max longitudinal range

My problem is that I have a load of geographic point data (srid 4326) in a table. A user may do a bounding box search - essentially create a polygon as follows: l_poly geography(Polygon,4326):= ...
0
votes
1answer
266 views

Using the ArcGIS Runtime SDK for C# is there a method to Hit Test for a polygon on the graphics layer?

I am very new to using ArcGIS runtime SDK for C#. I have loaded a polygon from a shapefile. I wish to query if a lat/long point is inside or outside the polygon? How can I do this? Thanks in ...
2
votes
1answer
41 views

Spike finder in PostGIS

I tried to modify spikeRemover from Schmidt & Krüger. My goal it's to obtain, for each polygon, the position of the spikes. I don't need to remove it. For some reason, that I can't figure out, my ...
2
votes
2answers
217 views

Change points to polygon

I have a map which has one data point per zip code. I would like to change those points to zip code polygons. Any ideas on how to go about it?
3
votes
2answers
102 views

Can I convert the sharp edges of a polygon easily to round edges?

I use the python module "shapely" to make Polygons (like below). Can I convert the sharp edges of a polygon easily to round edges? Such that when I have unified some polygons I could issue a command ...
5
votes
1answer
364 views

Easily calculate “roundness/compactness” of a polygon

I am trying to find ways to quantitatively describe the shapes of various polygons. For my project, these polygons represent lakes, rivers, lagoons, and parks. So they can be almost any shape. One ...
0
votes
0answers
19 views

Is there a way to convert L.circle to a geodesic polygon in Leaflet

Reference: How to make a predetermined Polygon (Circle) From 4 Coordinates, The Radius and Center Longitude and Latitude in Openlayers Openlayers uses this function : createGeodesicPolygon Question: ...
0
votes
0answers
28 views

“Flood fill” polygon capture mechanisms in various GIS

Within our organisation we have a requirement to capture lines dividing land into chunks and then to create polygon features using aggregates of these divisions. In the example image below ...
1
vote
2answers
112 views

Looking for dissolve algorithm for Javascript

I have three adjacent polygons that together make up a larger shape. I need an algorithm that will dissolve the internal borders leaving only the outside border. An example would be a group of ...
2
votes
2answers
65 views

zoom over vector in leaflet

I have created a map from geojson file of administrative boundaries (polygons layer). Similar to this example. When the mouse is over the polygon feature, the cursor changes from hand to finger. In ...
2
votes
1answer
33 views

Is there a way to clip a polygon layer according to DEM elevation?

I have a polygon layer on top of a DEM. Is there a way to clip the polygon layer according to elevation, ie the clipped result being only those areas of the polygon layer between x and y altitude? ...
0
votes
1answer
35 views

Extract address data / Query point in administrative boundary

I try to create a DB in postgreSQL with all the postal adress data for a specific country. Actually I have this table full of data: id integer NOT NULL DEFAULT nextval('plz_id_seq'::regclass), ...
-1
votes
0answers
31 views

what is the math behind rasterization? Doubt [duplicate]

In Figure 4 you can see how the overlap is not complete (marked with circles). What I would like to know which algorithm that QGIS uses the rasterization? What is your standard? Is there a percentage ...
0
votes
0answers
12 views

Is it possible to add XML data as DataStore inside GeoServer?

I have multi-polygon with feature information in xml Some kind like below: <polygon> <color>red</color> <coordinates> 125.94517419942997,37.080000000100085 ...
1
vote
1answer
42 views

Get Coordinates of Voronoi Polygon Vertices [duplicate]

Is there any chance to get the exact coordinatas of the voronoi polygons? I am using Qgis software and I have the "center" (redpoint) of the polygons and I would like to export the polygons corners ...
0
votes
1answer
42 views

Query to create polygone from lines that touches in POSTGIS

I am trying to create polygons from a line layer with a spatial query in postgis the probleme is i dont have a lot of information on the lines only id of each line and geometry thanks for your help