A common GIS operation. Used to determine whether a point lies within a polygon's bounds.

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33 views

Speed up row-wise point in polygon with Geopandas

I have a geopandas GeoDataframe which contains some attributes and a geometry column which is filled with shapely Point(lon, lat) objects. Moreover, there is a GeoSeries which is equally indexed as ...
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12 views

Create a specific number points that are equidistant from each other and a constraining polygon

I want to create voronoi data visualizations per a set of constraining polygons, but to show the distribution of data between categories, I first need points that will serve as the reference for ...
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30 views

Arcpy script or other method for points in polygon per participant

Is there an Arcpy script or another way that I could use to find out the number of GPS points falling within each participant’s home neighbourhood as defined by an 800 meter network buffer around the ...
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2answers
101 views

Determine which points are contained inside a given polygon

I have these database tables defined: CREATE TABLE regions ( id SERIAL PRIMARY KEY, name VARCHAR(150) NOT NULL ) CREATE TABLE region_points ( id SERIAL PRIMARY KEY, region_id SERIAL ...
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26 views

constrain random points with a polygon in R using sp library

I have a map of London's waterways, which I've grided into a raster dataset to enable me to measure proximity to water from randomly generated points. What I'd like to do please is to constrain the ...
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50 views

Join spatial point data to polygons in R

I am trying to perform a spatial join between point data and polygon data. I have data that indicate the spatial coordinates of an event in my csv file A and have another file, shapefile B, that ...
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2answers
49 views

Mean values of points within a polygon layer

I have 2 shape files (1x points and 1x polygons). The points have different values (soil sampling results). What I want to do is to calculate the mean values of the points inside the different ...
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2answers
54 views

Why do I get green crossed circles instead when I try to move a point?

It's really horrible I must say. I sometimes have geometry issues and then try to go one by one through them and fix these cases. Therefore I mark the area points and delete them for instance. After ...
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1answer
67 views

Why is Shapely and contains_point not detecting point being on land?

I'm using the world shape file that can be found at https://trac.openstreetmap.org/browser/applications/editors/merkaartor-branches/merkaartor-0.14-fixes/share/world_shp/world_adm0.shp?rev=17052. ...
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21 views

Aggregate nearby points to develop equally sized regions in QGIS

I have a list of 4,500 points (lat, long, unique id, attribute). I also have a service territory which all of the points fall into. I would like to break the service territory (polygon) into 6 ...
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19 views

How to find out to which polygon each points belongs to in ArcMap [duplicate]

I have got a shapefile consisting of a number of polygons, and another shapefile with a number of points. I want to add a column in the points shapefile. For each point, I want the column to contain ...
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41 views

Generate random points in geometry near heatspots

I have an algorithm, that generates random points with in a given polygon (Generate random points in polygon. Algorithm question). The Polygons the points are generated in are communities or districts ...
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1answer
51 views

Gdal+Geos point in polygon test fails under MinGW64

I have to build a grid of points and remove the points that falls inside a polygon. Polygons are defined in a ESRI shapefile, points are in a list. This is how I make the test: OGRLayer *layer = ...
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85 views

How to generally determine if a Point is inside a Polygon/Region?

I have a region (i.e. closed polygon) like this given in cartesian coordiantes: 1: 628497 / 239586 2: 642383 / 249881 3: 657705 / 241262 4: 652677 / 230489 5: 631370 / 231446 6: 628497 / 239586 I ...
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1answer
76 views

Point-in-polygon using WGS84 geographic coordinate system

When running a point-in-polygon operation, is it valid to run that with polygon features in straight up WGS84 and a point in lat/lng, or should both be projected into a non degree based coordinate ...
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32 views

Capturing points slightly out at sea

I have two tables one containing points (points) and the other polygons (polygons). I want to generate a two-columns table identifying for each point of the first table the polygon containing it. So ...
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3answers
83 views

How to Count point in polygon + on boundary?

So I'm looking for suggestions in both ArcGIS 10.2 and QGIS on methods on how to count points within a polygon and points that fall on a polygon boundary without adjusting the data/points. The ...
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1answer
33 views

Point in zone problem in calculation

I have a strange problem that i believe its because the zone pass through international date line. My goal is to find if a point is within a zone and I use the geoPHP library, everything seems to be ...
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40 views

Match housenumbers on buildings (special case of point-in-polygon-test)

Task with example I'm working with geodata (country-size) from openstreetmap. Buildings are often polygons without housenumbers and a single point with the housenumber is placed within the polygon of ...
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2answers
84 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 ...
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86 views

QGIS assign multiple points data to closest polygon

I've got two layers: point layer polygon layer I need to add the points attributes to the polygon by location (if the point is on top of polygon add the atribute as a new field. I thought of ...
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2answers
129 views

Postgis: Point-in-polygon check + feature attributes inheritance

I have two tables in Postgis 2.1 database: Polygon features with a reach attributive information; Regular point grid; I would like to get a SQL query returning the regular point grid with ...
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1answer
238 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. ...
2
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1answer
68 views

Positons from GPS lanes inside a polygon

i have a lot of lanes like the orange lanes at the below picture (latitude and longitude values). Now i need all values from each lane inside the red polygon. What is the easiest way to realize ...
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2answers
412 views

Select points within a polygon and update attributes

This seems really simple but I can't get it to work. I have two feature classes, a polygon of sales areas for a city, and point layer of addresses. I want to select the addresses based on the sales ...
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49 views

Using Geoserver

I am new to GIS and interested in using Geoserver. I have had a look at tutorials and read some books on this but still feeling clueless. I intend to use C# to accomplish some tasks eg, plot points on ...
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86 views

node.js GeoLib fails on polygon that straddles the anti-meridian

geolib.isPointInside does not appear to work correctly when the polygon longitudes straddle the anti-meridian. I maintain a system with lots of polygons that do straddle the antimeridian (I'm in ...
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1answer
85 views

Associating location data from PostGIS for a Choropleth map?

I'm trying to build my first choropleth map from data that we have stored in our PostGIS enabled Postgres database. So far I've been able to build a map on Mapbox using a topojson set of UK postal ...
2
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1answer
55 views

How to get only one biggest point in polygon?

I have polygon and point feature classes. Every polygon have 2 points inside them. For output I need only one point with highest value. I need incorporate this step in ModelBuilder. I had idea about ...
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1answer
494 views

Geodjango - trying to get points within a polygon

I'm going through the Geodjango tutorial and trying to implement in my own project - I have loaded data from a shapefile into my model/database and I have a separate model that has a PointField. I am ...
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1answer
114 views

Closest point on a line segment from point outside the line

From the above pic I found the value x from line (p1,p2) and point a. Using y=mx+b and an imaginary red line which is perpendicular to the black line having slope -1/m and the intersecting point ...
3
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1answer
99 views

How to create randomly points within polygons for each row of a dataframe matching a Polygon ID with R

My question is similar to this post, but because there are no "perfect" answer and above all no reproducible example I open this question. I have a "SpatialPolygonsDataFrame" and a data frame. Both ...
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96 views

Creating a polygon around features

I want to create a polygon around a number of points so that all the points occur within the polygon. The purpose is to do this to a number of different features and see where they overlap.
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2answers
189 views

How to determine in which grid cell each coordinate of an x,y series is located?

I have a circular arena which I have divided into a number of equal-sized 'cells' using a grid-like arrangement of concentric circles and line segments (in grey below) and also a series of x,y ...
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1answer
41 views

Count points in a polygon that changes form (“on the fly calculation”)

I have tried to find a plugin for this, with no luck. Perhaps someone knows of a plugin that can do the following: In this project I create a lot of polygons that contain points, and the size of the ...
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1answer
81 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 ...
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2answers
206 views

Find all points in a linestring that are contained by a polygon

I'm fairly new to PostGIS, so I apologize if this has been answered before. I have a linestring made up of 4D points and I need to determine which points in this linestring fall within a specific ...
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1answer
97 views

Adding points in Empty Polygon

I have a number of polygons on which I wish to make analysis using points data symbols... Is there a method through which I may add points automatically within each polygon in separate locations. For ...
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93 views

Programmatically selecting features by polygon

Expanding upon this post how could you use QGis to programmatically draw a selection polygon and select features within the polygon? I have been using QgsMapToolEmitPoint(self.canvas), to find and ...
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2answers
75 views

How to find all features in one table that intersect features in another table in PostGIS?

I have two tables, boundary polygon table and location point table. I need to find all boundary polygons that contain at least 1 location point. What is the proper way to do this in PostGIS? I tried: ...
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2answers
474 views

Find maximum and minimum value of points within a polygon buffer?

I have a series of 500m buffer zones along a polyline. I also have a series of points following the line, each point represents a 10m x 10m cell. I calculated the values of a field in each point known ...
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1answer
54 views

Weird ST_Contains behaviour

I'm creating a polygon and then checks whether one of the origin points is contained inside the polygon. To my surprise, I get False (?!) What is wrong here? SELECT ST_contains(ST_GeomFromText('POINT ...
2
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0answers
103 views

Using polygons with libspatialindex

I am investigating using some C/C++ libraries for point-in-polygon lookups and libspatialindex seems popular. I've written some code that seems to do what I want but I'm not entirely sure if what I ...
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3answers
152 views

How to count points once with overlappying polygons?

All, We're using parcel data (polygon) to count student locations (point) based on parcel type. We're doing this using SQL and the ST_Intersects function. It works great, except the City and County ...
1
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1answer
186 views

PostGIS ST_Within returns zero data

I am using PostgreSQL 9.3.3 & PostGIS 2.1.1 and I have a table Entries which has a column called "latlng" of geographic type (this column stores entry's latitude and longitude coordinates). I am ...
7
votes
3answers
2k views

Overlay a spatial polygon with a grid and check in which grid element specific coordinates are located

How can one use R to split a shape file in 200 meter squares/sub-polygons, plot this grid (incl. ID numbers for each square) over the original map below, and evaluate in which square specific ...
2
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1answer
60 views

Identify geographic location to points

I am quite new in QGIS and I really need your help. I have a map of Kenya divided into 68 districts and I have coordinates of 30.000 schools. The points have one variable besides the latitude and ...
3
votes
1answer
66 views

Qgis creating point within complex shapes (with holes) [duplicate]

I'm looking for a tool to create a point in every polygon, that will be placed in the polygon. these are complex shapes with holes. the point must not put in those holes! the "plugin RealCentroid" ...
4
votes
1answer
1k views

Shapely unable to tell if polygon contains point

For an application I want to determine under which constituency a given coordinate falls. After looking at the various options, I decided upon shapely and fiona as the easiest way to implement this. ...
0
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1answer
31 views

Determine when a route enters and leaves a polygon

I have all of the segments of a route from White Horse, YK to Miami, FL. Now I want to determine how many miles I travel in each State / Province. I have Polygons for each State and have been able ...