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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3
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0answers
23 views

What is the area that OGR extracts from the (geometry) shp files for polygons?

The ESRI July 1998 technical documentation for polygon shapefiles at page 10 makes no mention of either area measures or length measures (apart from byte/record-layout matters). Yet OGR enables me to ...
2
votes
2answers
56 views

Editing a Single Polygon Outline

Mapping geological contacts often needs true contact and inferred contact. I would like to know if it is possible to divide a single polygon outline which marks the outline of a granite body, so that ...
3
votes
0answers
47 views

Algorithm to find the boundary grid points [duplicate]

Let us consider a set S consisting of a collection of grid locations (i,j),i,j=1,\ldots,n, in 2-dimensional gridded plane. Here the point (i,j) corresponds to a rectangular grid in the X-Y plane. ...
5
votes
3answers
243 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 ...
1
vote
0answers
33 views

How to find the the boundary co-ordinates from a given set of coordiantes? [duplicate]

How to find the the boundary co-ordinates from a given set of co-ordiantes? I understand that this question asked previously and answered here How to find the boundary co-ordinates from a given set ...
3
votes
0answers
26 views

Dilating a polygon by a circle sector

I want to dilate a polygon by a circle sector in ArcMap. Because my python skills are not that good to figure out how I can use the R prototype of How to create an oriented buffer using arcpy? . Is ...
3
votes
3answers
53 views

How do I draw smooth vertexes around curves in ArcMap 10+?

I have some polygon layers (parcels) that have vertexes drawn around curves, as if traced. How do I click and drag to draw vertexes in a smooth shape? Big difference between what was originally there, ...
1
vote
1answer
94 views

Need to quickly know (CLI) whether point lies inside polygon

in my app I am parsing an XML from the web which gives me such coordinate info: I am able to use my app to get a pair of float values like 14.871381 and 50.065968. I do not want any complicate ...
7
votes
3answers
1k views

Create a square grid polygon shapefile with python

i have the following coordinates minx,maxx,miny,maxy = 448262.080078, 450360.750122, 6262492.020081, 6262938.950073 i wish to create a square grid of size 1 m using python. import math ...
0
votes
1answer
452 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 ...
2
votes
5answers
260 views

Make a polygon out of a polygon's hole?

I have a large polygon with many vertices that has a hole in its center. I want a polygon of the hole, the empty space. How can I easily do that? (It is much too complicated to digitize easily)
2
votes
3answers
218 views

How to change 0,360 WKT string to -180,180?

I'm reading POLYGON WKT strings using OpenLayers.Format.WKT().read(). The polygons use 0,360 longitudes but my map is -180,180. When I display the polygons on the map they are displayed outside of the ...
1
vote
2answers
94 views

How to resample polygon vertices so that they are evenly spaced in Arc 10

I have digitized the outline of many river channels (by both manually picking points and using streaming mode), but now I need the vertices to be evenly spaced (for input to another program). I tried ...
2
votes
3answers
50 views

Removing small polygons gaps in a Shapely polygon

I know this issue has been addressed before with different software, but I am looking for an approach with Shapely. I have a polygon with a very small gap on the interior of the shape: Here is a ...
1
vote
1answer
35 views

Cutting polygons into smaller (more regular shape) chunks

I came up with a polygon shapefile like what you see here. There are some small polygons which exactly match what I want, though I want to cut(split) those bigger ones into smaller pieces. So far I ...
5
votes
1answer
392 views

Rgeos drops associated values when intersecting polygons

I am trying to intersect two SpatialPolygonsDataFrames and get a SpatialPolygonsDataFrame as the result. Unfortunately, using the gIntersection function from rgeos (which works impressively quickly ...
2
votes
3answers
3k views

How to aggregate points to polygons using ArcGIS Desktop?

I am trying to aggregate my data points to the polygons so that I could find out how many points I actually have in each polygon, and then export the data contained within each polygon to further look ...
3
votes
0answers
47 views

Geoprocessing tool for finding specific point within polygon

I have a ArcGIS task and cannot find a solution. I try to find a certain point within a polygon (see picture). This example is handmade and I need a geoprocessing solution I point I try to get is ...
2
votes
1answer
41 views

Join attributes from multiple polygons to an overlaying polygon

I have a polygon-shapefile, containing 562 single features (feeding -layer). I want to add their attributes to an overlapping polygon-layer (bear_buffer -layer), containing 1330 features. The ...
1
vote
0answers
28 views

Invalid join selectivity error in postgis 2.1.3

I have 2 tables, one for points and one for polygons. I want to find points falling within theese polygons, so I quered: select p.id, l.id from points p inner join polys l on st_contains(l.geom, ...
2
votes
1answer
116 views

Count overlapping polygons in single shape file with R

I have a shapefile of species ranges for ~ 346 species. Some species have multiple polygon ranges so there are 1,078 polygons and many polygons are multi-part. It looks something like this: I ...
1
vote
2answers
98 views

How to draw polygons in shapefiles

I've hit a snag and realize this is probably a very simple and basic question, but how do I draw a polygon in a shapefile that I've created from joined points of 2 .csv files? Which specific tool do I ...
1
vote
1answer
49 views

How to add IDs of the links composing a polygon?

I built up a polygon layer from a road network for finding roundabouts using the compactness factor of a polygon. Then I have to intersect the extracted roundabout polygons with the road network so ...
2
votes
1answer
49 views

Polygon files corresponding to Russian Census

My team is using the 2010 Russian Census and we'd like to have polygons that correspond to these population values. We're flexible to any sort of polygon format (shapefiles, GeoJSON, KML, etc). ...
2
votes
1answer
165 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 ...
0
votes
1answer
298 views

How to calculate the percentage of distribution in each polygon?

I have binary map for disease suitable area and I want to calculate the percentage using pixel count in each polygon how can I do that? I use zonal histogram and do have frequency for each polygon is ...
1
vote
1answer
32 views

IdentifyTask for “hollow” polygon (using ArcGIS API for JavaScript)

I have a web map application set up that's currently testing on a variety of Dynamic Map Service layer types, including points, lines, and polygons. This application includes a tool that makes use of ...
2
votes
2answers
54 views

Finding a point inside a polygon based on maximum value of a specific field

I have a Polygon Shapefile that represents US counties and a Point Shapefile that represents hospitals. The hospital attributes table includes fields like "Number of Beds", "Number of Patients" and ...
3
votes
2answers
2k views

How to subtract Geometry Point Polygons in OpenLayers?

I have two json arrays, one for background polygon and one for other polygon. And from them, I got two polygon layers. backgroundLayer = new OpenLayers.Layer.Vector("Background Layer", {styleMap: ...
1
vote
0answers
27 views

QGIS 2.4.0 doesn't support multiple types of geometry in GML file

I'm testing GML 3.2.1 data according to INSPIRE Data specification (version 3.0). Data for theme Cadastral Parcels shall have both polygon geometry and definition point. When I download data from my ...
11
votes
1answer
3k views

Instantiating spatial polygon without using a shape file in R

So, the usual way we read a shapefile in R is via the maptools package, like this: sfdata <- readShapeSpatial("/path/to/my/shapefile.shp", proj4string=CRS("+proj=longlat")) However, I have a use ...
0
votes
2answers
51 views

Count the number of points in a (multi)polygon in shapely?

I'm using Python, Shapely and Fiona to process some shapefiles. Is there an easy way to count the number of points in a polygon/multipolygon in Shapely and Fiona?
1
vote
0answers
22 views

How to use GIS data with CGAL?

I read a few posts here at GIS.SE that points to useful algorithms in CGAL. I'd like to test algorithms in CGAL such as medial axis transformation/polygon skeleton extraction, but the examples on the ...
4
votes
2answers
180 views

Order of polygon vertices in general GIS: clockwise or counterclockwise

Two days ago I asked a question about the internal storing order for the vertices of a polygon in ESRI shapefiles. That question was answered (Are polygons stored clockwise or counterclockwise in a ...
1
vote
1answer
38 views

Convert raster to polygon based on cell value ranges using ArcGIS for Desktop?

I have a floating point-valued raster which I need to convert to polygon as follows Put the cells with VALUE < 0.5 into (a small/the smallest number of) polygons Cells in the range [0.5, 1] into ...
1
vote
2answers
89 views

How to draw a polygon given a distance and bearing in QGIS

Apologies if this question has been asked before I'm not come across it. I want to draw a polygon given a length and a bearing, basically a square with lenght 1m. I cant seem to manage it with the ...
4
votes
2answers
88 views

Wrong $area from field calculator (QGIS)

The area of the polygons in a layer, calculated by the field calculator with "$area" is wrong (much too big) for some polygons. If I draw the concerned polygon again, the area is calculated correctly. ...
5
votes
1answer
484 views

How to Create Touching Multi-Part Polygons?

I have a set of parcels as illustrated in the image below. There are currently no multi-part features in dataset. What I would like to do is to merge (not the right word) all of the parcels with same ...
0
votes
1answer
24 views

Add Marker on the polygons' centre using Openlayers?

I have written a code to draw polygon from the WKT format.Now I need to add the marker at its centre. In the following code I have passed the centre and shape in WKT format(extracted from database). ...
2
votes
4answers
203 views

Polygon Shape Data for North America

Does anyone know where I can get data like this for north America (for use in SSRS). It does not have to be exploded. If I add Bing maps my 36 page PDF is 250MB when exported!
3
votes
3answers
195 views

How to count the sides or edges of a polygon?

I wondered if it is possible to determine the number of sides / edges (not vertices) that a polygon has. Imagine the following case. There is a shapefile with 10 polygons. Is there any way to ...
1
vote
1answer
66 views

How can I convert GeoJSON with multiple Polygons and MultiPolygons into single MultiPolygon?

Is this even possible? I have a GeoJSON file with multiple polygons and multipolygons, and I need to set styling on them (in Leaflet.js). I'd like to create a single, large MultiPolygon from the ...
3
votes
1answer
84 views

Polygon fill colour specified by column R spplot

I am trying to plot a geological map using the spplot function in R. For every unit I already assigned a specific color in the col-column of the SpatialPolygonsDataFrame. Now I would like to plot the ...
2
votes
2answers
185 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 ...
1
vote
0answers
54 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 ...
3
votes
1answer
101 views

problem with polygon smoothing in R

With R I am looking to smooth my Polygon: inter2.csv code: inter1 <- read.table("c:/inter2.csv", header=TRUE) # add a category (required for later rasterizing/polygonizing) inter1 <- ...
3
votes
2answers
122 views

Merge geojson polygons with WGS84 coordinate

I have a Geojson file with some adjacent polygons and I want to merge them into one. I know it's a recurrent question but I can't find information for polygons with latitude and longitude coordinates ...
3
votes
2answers
240 views

google map api v3 large/complex polygons

I have quite some large/complex polygons I'd like to overlay on a Google map. I can do this but wondered what the best/fastest way is to load them? I have tried using a KML but understand there are ...
1
vote
1answer
70 views

Find all street names or addresses within a polygon

I have a geojson list of lat/long coordinates that make up a custom polygon of a section of my county. Ideally I would like to be able to find all the addresses that are within the polygon boundaries. ...
3
votes
1answer
74 views

Showing Linestring from SQL statement with CartoDB

I have cartodb sql statement to return what polygons are intersected by a linestring, but I'd like to have the linestring visualized over the polygons on the results. Also not add the linestring to ...