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
0answers
20 views

Can I reorder the points in a GEOS LineString?

Using libgeos, when I buffer() a polygon and then getExteriorRing() [to make a slightly smaller outline copy of the polygon just inside the original], it seems that which point on the new geometry is ...
3
votes
1answer
460 views

Determine when I have crossed state line?

We are currently using the Google Maps API to get route information and total mileage but we would like to determine when we are crossing into a new state. When we return the route information we can ...
1
vote
1answer
112 views

How to reclassify raster data that falls within a polygon

Thansk for your response Okay so I will reword my question more clearly I'm currently using ArcGIS 10. My task is to map forest cover with the image classification tool. The problem is some of the ...
1
vote
0answers
11 views

Why does connected polyline (KML file) appear unconnect in arcmap as layer?

I created polygone in google earth and imported it to arcmap as layer. All things are OK but when I converted polygon to polyline, there some parts of polyline has not shown although its vertices ...
0
votes
1answer
9 views

Finding neighbors for non adjacent polygons in R [on hold]

I'm looking for a method or function in r-project that create a neighborhood matrix from a group of polygons that don't touch each other, like polygons of set of blocks separated by streets in a town. ...
1
vote
3answers
52 views

Comparing size between polygons in different UTM zones

I am going to compare size of different areas in Europe in different UTM zones. The areas I'm comparing are quite small (around 35-50 km2) and I was wondering how to do this the best way? Can I draw a ...
1
vote
1answer
243 views

how to find that two polygon boundaries are connected?

I am working on a Geo database where there is a layer with many polygons. i want to find that which polygons boundaries are connected so that i can create new layer from that polygons and which ...
0
votes
0answers
5 views

OpenLayer WMS Polygon Fill color dynamically

i am new to OpenLayer Geoserver and PostGIS. I want to color my WMS Polygon Layer which has multiple polygon in different color based on some value. Is this possible with wms or wfs. Color for polygon ...
0
votes
1answer
1k views

How to narrow the result from Nominatim with only cities and countries, no additional areas with the same name?

I'm trying to get WKT or GeoJson polygons of cities and countries from Nominatim (for example, Paris and France). I send a GET request but it returns me several results named "Paris" or "France". How ...
1
vote
1answer
22 views

Storing GML Polygon in PostGIS 2, ERROR: unknown spatial reference system

I am receiving GML as part of a larger XML message. When I receive the XML it is unmarshalled to Java objects. I have no rights to alter the schemas or the generated Java code. Therefore, I later have ...
4
votes
2answers
61 views

How to place only one symbol on the centroid of a multipart polygon?

I am using QGIS version 2.14.1 (Essen). I would like to place symbols on the centroids of my data. The problem is that some of my data has multi-part polygons, which means it places the symbol at the ...
2
votes
0answers
19 views

How do I merge a point attribute table to a polygon attribute table in QGIS or GRASS?

I have a point layer containing the following data: I want the following polygon areas to be added to the point attribute table as all the points occur inside the various features of the polygon ...
3
votes
1answer
46 views

Rule based polygon fill in QGIS

I'm really quite new to QGIS, I want to style polygons fill with raster imagws based on a attribute contained in the property table. What do I have to write in the description in order to get for ...
2
votes
2answers
84 views

What is the difference between Polygon To Line and Feature To Line in ArcGIS?

What is the difference between Polygon To Line and Feature To Line in ArcGIS? Is feature to line a more abstract way such that it takes in not only polygon but like dots and other feature classes ...
1
vote
1answer
172 views

How to transform isolines to isopolygons with postgis?

I have a table a postgis table of isolines that's defined like this: CREATE TABLE myisolines ( gid serial NOT NULL, isotime timestamp without timezone, val numeric(10,4), geom ...
1
vote
1answer
19 views

ArcGIS: segmenting buffer based on polygon corners

I have hundreds of square polygons which I've created a single continuous buffer around the polygons. What I'd like to try and do is try and break this buffer down into segments based on the corners ...
5
votes
2answers
137 views

Are there any multipolygons in my shapefile?

In QGIS 2.x, is there a simple way to determine if a polygons layer contains multipolygon geometries and if yes: which are these features?
0
votes
2answers
1k views

How to export to all points within Leaflet polygon?

Is it possible to export all points within a polygon drawn using Leaflet? (http://leaflet.github.io/Leaflet.draw/).
3
votes
1answer
24 views

Change feature class from ESRI native geometry to SQL Server geography

Original question: I have found a lot of documentation on importing and using query layers from SQL Server into ArcCatalog/ArcMap/etc. However, when you change the projection of a feature class or use ...
2
votes
2answers
167 views

How to quickly fill multiple gaps in a series of adjacent polygons

I've been given a "background" dataset which is designed to draw as the first layer in a complicated map. For some reason the data provider has previously erased this dataset with roads, parks, etc. ...
3
votes
2answers
67 views

Polygon shapefile has irregularities when viewed in ArcMap?

i am using ArcGIS 10.4 for Desktop and when i try loading my shapefiles into the arcmaps it shows extra incorrect lines in my polygon shapefile is there anyway to fix this inconsistencies ...
1
vote
0answers
21 views

Filtering Small Areas of Shapefiles Using R

I'm trying to use the method proposed by the @ialm in the Question "How to speed up the plotting of polygons in R?" There, he loads the maps using getData from the raster package, I tested and it ...
0
votes
0answers
21 views

Percent overlaying [duplicate]

I have a raster dataset of points and a polygon features. The two are over the same area and I am trying to find the percent of the raster that overlaps the polygon features. I have tried clip, ...
0
votes
1answer
35 views

Intersection of a raster and polygon in ArcGIS 10.3

I have two data sets one raster and one polygon. I am interested to see learning the area where the two overlap. I was thinking that I could use the intersect function, but since one of the layers are ...
5
votes
2answers
96 views

How to sum attribute values for areas where multiple polgons overlap?

I have one shapefile with many polygons (at least 100). Each polygon has a value. Almost all these polygons overlap with each other. I want to sum the values of the polygons in the overlappings depend ...
3
votes
0answers
21 views

Create an optimised path between nodes avoiding polygons entities

I have nodes as a shapefile representing seaports. I have the linear cost of shipping for every pair of seaport (specific shipping cost to go from one node to another node). I want to find a way to ...
-3
votes
0answers
32 views

Python code to calculate area and perimeter [closed]

I want to calculate area and perimeter for many features (polygons) that have been saved in separate files. How can use python script to calculate these parameters and output them in one table for all ...
0
votes
0answers
14 views

Using Python to output table of intersecting polygons in ArcGIS for Desktop? [closed]

I have two polygon layers: routes in a transit system with a quarter-mile buffer draw for each route and the number of daily trips on that route, and Census data at the Block Group (BG) level. ...
0
votes
1answer
25 views

Identifying the closest polygon to a point dataset

I have two large data sets one point and one polygon. What I was looking to do was identify which polygon is closest to each point. Hopefully I was looking for a automated process as the point data ...
0
votes
1answer
6k views

Merge attribute of points into a polygon : Arcmap 10

I have points layer which the attribute looks like this: FID Shape ID Lat Long 0 Point 2065 -5.51666 106.48333 1 Point 2319 21.93333 120.73366 I also have polygons layer : FID Shape ...
1
vote
2answers
40 views

Animating polygon style over time in QGIS?

I have a shapefile, consisting of polygons. I can join a layer to a database file, and use an attribute (database value) to "style" (color in) the polygons to give me a visual representation of the ...
3
votes
3answers
33 views

Convert .csv with polygon geometry to .shp QGIS

Working on a Mac in QGI 2.12, I have a csv file with polygon geometry coordinates that I would like to save to a shapefile. It displays fine as a csv. However, when I try to use "save as," I get the ...
1
vote
1answer
21 views

“Direction/Length” Tool not working with Polygons in ArcMap 10.3

My "Direction/Length" right-click option is not working when trying to draw a polygon. I start a shape by dropping a single vertex, right-clicking and choosing "Direction/Length". I enter in the ...
1
vote
1answer
26 views

Colour a polygon depending on the number containing of point feature

I have 2 different shape files, polygon and points.I am using QGIS 2.14 as a software. The points are distributed inside of the different polygon shapes. I try to do a categorized map using different ...
1
vote
0answers
16 views

Splitting polygon into multiple fixed-width polygons along edge in R?

I have a polygon and would like to spit into grid with fixed width along with one edge. The result will look like the figure below. Are there algorithm to achieve my target? My language is R, but ...
1
vote
1answer
28 views

Checking if point is inside irregular polygon?

I'm using Javascript (https://github.com/substack/point-in-polygon) to test if a point is inside polygon, however I think it's adapted from ...
0
votes
1answer
118 views

Labelling polygon using QGIS?

Using QGIS 2.4, I have tried labeling a polygon using the layer properties>label function but it doesn't show my label. How and where do I type the text I want and get it to show?
1
vote
0answers
21 views

Offsetting polygon borders where they share border in QGIS?

Say you have 2 polygons with different coloured borders, where the borders are shared the colour is problematic. How do you offset/separate them in QGIS 2.10.1?
3
votes
1answer
680 views

Extract data from netcdf using a shapefile polygon in python

I need to subset data from a NetCDF using a specific shapefile. The data are sea surface temperature and ocean color at 1/4 degree resolution. I have 4 polygons describing the US. Northeast ...
1
vote
0answers
71 views

Polygons within Polygons Spatial Analysis

I have a polygon layer of planning applications and I am wondering if anyone can give any advice and or has seen or written a blog post that might point me in the direction of creating relationships ...
1
vote
1answer
17 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 ...
14
votes
6answers
16k views

Performing a reverse clip in ArcMap?

Is there a way to perform a 'reverse' of the clip function in ArcMap, I'm not exactly sure how to explain this so here's a diagram:
1
vote
1answer
14 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 ...
0
votes
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 ...
0
votes
2answers
257 views

Extracting multiple values of raster to polygons using ArcGIS for Desktop?

I was hoping I could get some help on how to extract information from a land use raster using polygons. I have a layer with 157 polygons and a land use raster with multiple land use categories for the ...
-1
votes
0answers
25 views

How can I search for elements within a polygon specified by coordinates in Overpass?

I am new to overpass API and GIS in general. Is there an easy way to export all buildings in a specific region using coordinates to specify the polygon? I couldn't find a solution using the wiki and ...
1
vote
1answer
17 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 ...
1
vote
1answer
494 views

Is it possible to draw polygons along Google Maps Polyline?

Web application has option that user draws polyline on Google Map. After he draws it, there is a button 'Add polygons', which should draw polygons along that line, based on some width and height in ...
1
vote
1answer
3k views

How to write a point-in-polygon query for Postgis?

I'm trying to write a query in Postgis which will return all rows where a dynamically changing longitude/latitude point resides within the geometric polygon of that row (in the geom column). This is ...
13
votes
9answers
10k views

Algorithm for finding irrregular polygon centroid (label point)

I need to find a centroid (or label point) for irregularly shaped polygons in Google Maps. I'm showing InfoWindows for parcels and need a place to anchor the the InfoWindow that is guaranteed to be on ...