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
3answers
201 views

Find closest point between polygons inside other polygon

I have access to ArcInfo (ArcGIS 10.1). The dark polygons are settlements. The green polygon is derived from a suitability analysis. The surrounding white area is restricted. I want to find a point ...
4
votes
1answer
784 views

Leaflet JS add GeoJSON shape as a hole in a polygon

I have a dataset which already contains geojson. I can add it to my map with the following line of code. L.geoJson(data.geojson).addTo(map); And I get this But I want to achieve this, where the ...
4
votes
1answer
2k views

Extracting intersection areas in R

I have two polygons. One contains fields(X,Y,Z) and the other contains soil types (A,B,C,D). I want to know what area of every field contains which type of soil. I tried the following: ...
1
vote
1answer
30 views

Workflow for updating raster using polygons of different attributes

I require a specific output but it is proving difficult for me to work out a workflow. I have: 1) polygons of new housing developments (356, non overlapping) 2) a 25m raster of land cover I want ...
1
vote
0answers
19 views

Overlapping polygons: how to sum attribute values for areas where multiple polgons overlap [duplicate]

I have what seems to be a fairly simple problem but I cannot find a solution. Any help would be much appreciated. I am working in QGIS 2.8.1. I have a shapefile of polygons, each of which has a ...
1
vote
1answer
218 views

Order a list of points to make a polygon with smooth outer border

I have a function that pulls some lat/longs from a Database and then I put those values in a polygon to see it's shape. The problem is they are so random in position and direction from each other that ...
16
votes
3answers
6k views

Proper way to rbind SpatialPolygonsDataFrames with identical polygon IDs?

What's the proper R idiom for rbinding SPDFs together when the IDs overlap? Note that here (as is often the case) the IDs are basically meaningless so it's pretty annoying that I can't just make ...
1
vote
1answer
112 views

Country border between two points

I am trying to extract country borders between two points, using Python. The border is a Shapely Polygon.exterior or LinearRing, the start and end points are Shapely Points. My idea is the following: ...
0
votes
0answers
45 views

How to arrange polygon in Postgis

I have a lot of polygons in a Postgres database. I want to show the polygons, but in order of the the biggest to the smallest. I used the following code: SELECT ST_Area(area_polygon) as luas FROM ...
1
vote
0answers
55 views

Splitting up a single polygon into many polygons of equal point count

I have point data split into 15 different values and want to split up the (green) polygon into a number of smaller polygons each containing the same number of points so that I can make a chloropleth ...
4
votes
1answer
355 views

Validating polygons for no gaps/overlaps/slivers using ArcGIS Desktop?

I would like to assess the spatial accuracy of a load of polygon shapefiles which are supposed to show air quality for a bunch of countries. Firstly I want to assess whether each shapefile has a ...
9
votes
4answers
43k views

How to create polygons from lines?

I am trying to create polygons from a line layer of lots and concessions (large blocks of land in rural areas). The lines are mainly grid style as they intersect mostly at right angles. I need to ...
0
votes
1answer
193 views

Getting the max value from where polygons intersect in MapInfo

I am trying to do an intersect query on two polygon layers in MapInfo. One is a buildings layer and the other are 2d mesh triangles. I want to get the max depth from any of the triangles that ...
1
vote
1answer
477 views

Summarize polygon area using another polygon

I have a shapefile representing public/private lands in Montana. This is a multipart shapefile where I've simplified attributes so that #1==private and #0==public. Next I have a shapefile of ...
0
votes
0answers
47 views

summarize multipart feature by another multipart feature

I have one shapefile with many polygons, each representing the area of a selection of crops. I would like to determine the total area of each crop by county using a shapefile of counties in Arcgis ...
1
vote
1answer
156 views

ST_Intersection for polygons

I'm looking for a query that returns overlapping areas of two tables with polygon geometries. Using row_number() over() the entries of the gid column are not unique in the case of dumped ...
6
votes
2answers
202 views

Summing up over area based on distance related function?

Through a field study, we learned that the density of a bird species in the forest was related to the distance to forest edge: ln(density) = 1.89*(distance to edge) + 0.34 Now, for any forest ...
1
vote
3answers
820 views

How to create one KML per polygon (from one Shapefile)?

I have a shapefile containing hundreds of polygons. I need to create a kml of each of the polygon. Is there any way that I may not have to deal each polygon individually and my polygon file may give ...
1
vote
2answers
1k views

Adding values to Fishnet Grid?

I have developed a fishnet grid for my study area. I have various datasets for the area and want to allocate a value (from one of the pre-determined datasets) to each polygon within the Fishnet. ...
1
vote
1answer
35 views

Not all polygons removed when cutting from vector layer in QGIS

I have created ten polygons representing lakes on a vector layer, and I am trying to cut them from an imported and re-projected vector layer of administrative districts. When I use the 'Cut with ...
5
votes
1answer
90 views

Clipping features depending upon percent coverage by other features

I have a shapefile composed of several thousand square polygons of equal size, arranged in a grid. I have another shapefile with a few dozen circles. The squares are about 1/10th the size of the ...
0
votes
0answers
37 views

Aggregate polygons based upon adjacency to an acreage threshold

I work as a forester. I have a feature class of approximately 750 polygons that range in size from a few acres to more than 250 acres. I would like to combine these polygons based upon their proximity ...
3
votes
2answers
225 views

Extract polygon points

I have a map in .shp format with buildings. I'd like extract the coordinates of this polygon. E.g. if a house has a polygone of 4 points, i'd like to know the coordinates of those points and how to ...
0
votes
0answers
105 views

Points nearest to polygon: nearest to edge of polygon or centroid?

When using ArcGIS and performing a Spatial Join of points to polygons, there is an option to choose the closest point. Is the point that is chosen closest to the edge of the polygon or to the centroid ...
2
votes
2answers
391 views

Merge polygons in CartoDB?

I created this map in cartodb: http://cdb.io/1xBj4Xo Now I have to merge some of the districts to a bigger district. Is it possible to do this in Cartodb? Using a SQL query for instance? I can also ...
1
vote
2answers
1k views

Dissolve polygons - group to others with touching corners

I am working with some data that shows land management. There are many places where corners "touch". I would like to dissolve my dataset so that features are grouped (dissolved) with those that they ...
3
votes
3answers
1k views

ArcGIS - possible to set the drawing order of polygon features [duplicate]

I have a table with polygons that I wish to display in a map. I would like the smaller polygons to appear on top of larger polygons. Is there a way to set the drawing order such that the larger ...
0
votes
0answers
115 views

What is the best way to store GML polygons in MySQL?

I have large .GML files with polygons of regions around the country, some are a single polygon, some are multiPolygon. What is the best way to store this in MySQL? I was assuming that I would ...
0
votes
0answers
56 views

Merging two regions of several into one, to get output SpatialPolygonsDataFrame file

I've been using the large SpatialPolygonsDataFrame file with outdated border of regions. I want to correct boundaries, but also hope to get in the end Polygons with Data Frame again. I used the ...
0
votes
1answer
120 views

How to eliminate polygon overlap areas in QGIS?

Is there a way to remove polygon overlaps within the same layer using QGIS, preferably removing the overlap area of the biggest polygon (having the greatest surface)? All of my polygons are in the ...
0
votes
0answers
89 views

Convert polygons to optimized lat long radius

I have a research project where I need to search Instagram and Twitter for geo coded data. The APIs allow lat, long, and radius, but I have shape files with polygon shapes and some long lines (think ...
1
vote
1answer
39 views

Number of lines within specified distance of thousands of polygons

I have ~5000 polygons in green (districts). I have storms that I am interested in as red lines. Each storm has a unique ID. Looking to add fields to the districts. The fields are 25km, 50km, 100km, ...
0
votes
2answers
189 views

Polygons of countries including territorial waters

Where can I get polygons (multipolygons) of all countries of the world including the territorial waters of the countries? OpenStreetmap displays these areas but I can't find an extract of this ...
2
votes
2answers
185 views

Cutting a polygon out of another polygon with python [duplicate]

Licence: ArcEditor Version: ArcMap 10.0 i have some issues to separat my data with python. To illustrate the problem, i have simplifyed the data with figures. I want to cut the blue polygon ...
2
votes
0answers
111 views

GDAL equivalent to ArcGIS Union?

I have a single shapefile full of overlapping polygons. The ArcGIS Union tool will generate individual, non-overlapping polygons with that geometry. Is there a way to do this with GDAL/OGR or another ...
1
vote
2answers
264 views

testing if a Geodesic polygon contains a point c++

I am looking for an algorithm, preferrably in C++, that can take a point (lon,lat) and determine whether that point is inside a geodesic polygon. Is there such an algorithm freely available?
0
votes
1answer
298 views

ST_Intersect with ogr2ogr and Spatialite

I am trying to intersect Spatialite datasets with ogr2ogr, the OGR Virtual Format and SQL Syntax. I can't seem to locate whether the error is in my SQL query or my VRT file. Data ...
0
votes
0answers
23 views

Need to find polygon info from postgis

After importing shapefile into postgis I got geom data as MultiPoligon Like: ...
2
votes
2answers
149 views

Automating selection and sliver elimination using QGIS

At the moment I do this manually: open a shape file open the attribute table use "select features using an expression" - the expression is "area" < 200 then I use vector/geoprocessing ...
1
vote
0answers
306 views

Efficient way of determining polygon intersection with bounding box

I have a set of polygons, and I need to check whether they are intersecting with a given bounding box(rectangle). What I am doing is, I am taking every vertex of polygon and checking whether it's ...
9
votes
1answer
319 views

PostGIS polygon edge analysis (orientation, edge length)

I am rather new to the world of GIS and especially PostGIS, so please excuse me if the answer seems evident... I would like to do analysis on a number of buildings. One thing I am interested in is ...
3
votes
2answers
272 views

How to automatically calculate maximum cell values contained within polygons?

I've got a dataset made up of a large range of polygons (about 70 or so) which represent structures. I also have raster layers which detail a flood depth across an area. The floods depth raster has a ...
4
votes
1answer
344 views

Polygon to Raster taking longer in script than in ArcMap?

I have a large dataset that I am working with. Basically I have a table with 900,000 records that I join to a geodatabase feature layer, then convert that to a raster. This process takes a total of ...
4
votes
1answer
1k views

Extract raster value to polygon

I am trying to extract raster values within multiple polygons. It would be nice if I could choose between say the maximum or an average raster value within the polygon. For example, I have created ...
1
vote
1answer
65 views

How to calculate the area of a raster within a polygon which is greater than a specified value?

I'm using QGIS (2.8.1-Wien) and I have a raster layer showing chlorophyll concentrations in the ocean. I have also defined number of regions of the ocean using polygons. What I'd like to calculate for ...
2
votes
0answers
98 views

Digitizing complex archaeological scenarios in various levels

I don't know if this issue has already been answered, but I can't get my head around it. I used to do this in Illustrator, and there it was simply a matter of clicking "bring forward/bring back" etc. ...
3
votes
0answers
276 views

Closest set of points to another set of (predefined) points

I have 10 sets of points which I call templates that I have manually classified from 0 to 10. Each point is a X, Y coordinate in a text file. Each template has 5-8 points. I have new sets of points ...
2
votes
2answers
13k views

Openlayers How would i get a hover label over my polygon

make a hover/mouseover label for a polygon in Openlayers? I made a map with draw, delete and drag polygon function. Now I need to make a hover mouseover for this. How to get a hover label for ...
1
vote
1answer
62 views

How to Convert db.ListProperty(GeoPt) to GeoJSON Polygon

My Python Google App Engine (no tag?) app has a datastore model of an Area of Interest, simplified as import geojson class AreaOfInterest(db.Model): name = db.StringProperty(required=True) ...
0
votes
0answers
84 views

Visualizing overlapping polygons by occurence

I work in a library providing geospatial services and I have a patron with about 60 surveys with perceived accent regions in Mexico. Individuals drew on maps where they think people speak with ...