Questions tagged [point-in-polygon]
A common GIS operation. Used to determine whether a point lies within a polygon's bounds.
328
questions
4
votes
0answers
25 views
How to choose limited number of points to represent a point grid
I need to choose a few points to represent the grid below, e.g: 8 points in the grid below. This point need to be geographic distributed
This points needs to be geographic distributed. Lets see a bad ...
1
vote
2answers
41 views
Using QGIS to buffer attributes on map
This is my first experience of using GIS systems.
Firstly, to give you an overview of my project, I am trying to analyze the obesity rates within the boroughs of London. I have gotten to the point now ...
2
votes
1answer
54 views
Calculating minimum distance between two point layers within polygons in QGIS
I have three vector layers two points and one polygon:
Centroids (POINTS FROM)
NUTS_ID | CNTR_CODE | NUTS_NAME | id
Sorting_plants_2020 (POINTS TO)
postcode | name | where | capacity | id
...
3
votes
3answers
57 views
Calculating value of unique points in polygon in PostGIS
I'm working with a spatial PostgreSQL database that contains species records, there is a point layer 'spp_points', each point has a "spp_ID" and "spp_score" field. I also have a ...
2
votes
0answers
13 views
Generating equidistant Points inside box which also contains MultiPolygon [duplicate]
I have a box bounded by min_x, min_y, max_x, max_y, I also have a multipolygon = poly contained in that box. I'm trying to equidistantly scatter points throughout that box, outside of that ...
1
vote
0answers
32 views
Getting attribute form data from another layer
I’m trying to use the attributes form in QGIS 3. Most of what I’m doing is relatively simple use of combo boxes but I’ve run up against a wall.
The idea is that I’m trying to streamline how we notify ...
3
votes
1answer
70 views
Updating table from another table with function ST_CONTAINS in PostGIS
I tried to update an attribute 'solved' of a polygon table (table name: polygon) by using an attribute 'solved' of another point table (table name: point).
What I want to do is that if ALL the points ...
2
votes
1answer
50 views
Spatial joins in ArcMap (points to polygons) - capturing points that are just outside of outer boundaries
I am working with geocoded crime event data, and attempting to join that point layer with a census block group layer in order to get a count for each census block group (and ideally sums/averages for ...
2
votes
1answer
43 views
Automatically output joined fields in input layer while using spatial join
For example, I have two layers:
A polygon layer city block with a ID field city block index.
A point layer parking lot with a field parking lot size.
I want to know the total parking lot size for ...
0
votes
0answers
34 views
Returning all points within a polygon
I've been trying to figure out how to use ST_Contains to figure out what points are contained within a polygon.
Here is my query.
SELECT "userId", "firstName", "lastName",...
1
vote
0answers
33 views
Aggregating data and displaying counts with GeoPandas
I have two datasets that I want to use. The first is a shapefile of King County that has polygons broken up by school districts. It has boundaries saved as polygon features on a geo-dataframe.
The ...
1
vote
1answer
55 views
How to generate a column with a count of number of points in a polygon AND have 0 for the rows where there are no points in the polygon?
I have two data sets with a large number of points that I’m organizing into a hexbin grid.
I'm associating these points with the hexbin polygons by using PostGIS to determine if a point falls within a ...
1
vote
1answer
54 views
Count points within a polygon
I'm trying to count the number of points within a polygon of a fixed size in R. I'm planning to do it a few times so that I can eventually calculate average density of points with some measure of ...
1
vote
2answers
55 views
Spatial Join also Based on Attributes using QGIS
I have two data sets:
points with a timestamp
polygons representing neighbourhoods
I need to compute how many points are in each neighbourhood polygon, based on a time range. So in other words, how ...
0
votes
0answers
30 views
Dividing country into regions based on some initial center point using ArcMap
I am new to GIS.
I have some lat-long (say 5) spreads across a country and I want to make polygons around each point such that all the polygons cover the whole area of the country and within the ...
0
votes
0answers
36 views
st_intersection only if specific conditions are satisfied
I'm new to sf package.
I have two sf files, one containing lat/long position of points (point_sf) and the other one containing sf polygon geometries (polygon_sf). I want to see which points belong to ...
2
votes
1answer
43 views
Determining how many of my coordinates overlap with layer in QGIS?
I am working on a project about a certain animal species. I have gotten coordinates from where the species has been observed.
Now I want to know what percentage of the observations are from gardens/...
2
votes
2answers
77 views
Counting points in polygons by weight and class in QGIS
I have seen a similar question to Counting points in polygon using weight and class simultaneously, but I was unable to operationalize the answer that I found so far.
I have a point layer with ...
2
votes
1answer
48 views
Counting points in polygon using weight and class simultaneously
I am using QGIS 3.1. I am wondering if there is a way to count points in polygons but by using both the weight and class.
For example, I have distributions of a number of species, each with a unique '...
3
votes
1answer
125 views
Fastest point-in-polygon solution with billions of points over thousands of polygons
Problem definition is quite simple: I need to achieve point-in-polygon detection for:
billions of lat/lon points
over thousands of polygons
I need to be able, for every point, to determine if it is ...
1
vote
0answers
45 views
Entry and exit point of the polygon
I would like to add to the attribute table somehow quickly a column containing the entry and exit kilometre data.
I have the available point layer with kilometre, road axis and polygon as shown:
...
4
votes
1answer
148 views
PyQGIS count points in polygon grouping by attribute
I have a point layer with an attribute table like this:
id_point class
1 A
2 B
3 A
4 C
5 B
...
What I need is to count how many points of ...
0
votes
0answers
35 views
Counting and print number of points from a CSV in a series polygons / buffered points in GEE?
I'd like to compare the number of calls from gps coordinates to the population around those coordinates in Google Earth Engine. My plan was to count the number of incidents (points from a table: ...
0
votes
1answer
34 views
Count points by non-continuous polygon in QGIS
I'm very new to QGIS and I'm learning by practice and reading both QGIS documentation and StackExchange answers. However, I think one of the main tasks has been naming the concepts correctly and look ...
2
votes
1answer
37 views
QGIS Random Points in Polygon PRESERVING Attribute Table?
I have a complicated shapefile of overlapping polygons. I need to generate random points inside each polygon, which is easily accomplished using Vector -> Research Tools -> Random Points Inside ...
0
votes
0answers
8 views
Calculating where map coordinates land within a collection of district boundaries? [duplicate]
The following coordinates make up the district boundaries of Westminster in the UK (point-to-point polygon):
51.4859, -0.1295
51.4846, -0.1498
51.4978, -0.1561
51.4978, -0.1796
51.5259, -0.2062
51....
1
vote
0answers
21 views
Fast solution to load and query shape files
I work on a .net core web API application collecting fishing events with latitudes and longitudes.
For each of these positions, I need to compute the corresponding Exclusive Economic Zone (EEZ), it's ...
0
votes
1answer
31 views
ArcMap: Identify mismatch between position of points from database with their actual location in polygons
A map in ArcMap contains two datasets:
Points J_i from table Jurisdiction of an SQL-database (SQL Server 2017) displayed by Display XY Data (Data Type: XY Event Source)
Polygon shapefile feature ...
2
votes
1answer
61 views
Points within Polygons given certain conditions
I am trying to locate all the points within a set of polygons given a certain condition on the polygon in MongoDB using Python 3x.
This question differs from the other ones because i) it requires ...
2
votes
1answer
28 views
Changing index order of points within the same polygon
I am currently trying to get rid of a waterway that divides my polygon. The problem is that the points are part of the same polygon but are around 190 rows away for each other.
Is there a way to ...
0
votes
0answers
22 views
OD matrix with origin and destination points based on polygons selections
I'm new in QGIS, and I would like to create an OD matrix. I have two shapefiles: one which contains the origins with POINTS(lat, long), and another one with destinations POINTS(lat, long). Each one of ...
2
votes
0answers
52 views
Optimising use of st_within for parallelisation
I'm trying to use st_within() to calculate points within polygons on a fairly complex shapefile. This operation tends to take 4-5 hours which is a bummer for debugging the code. I have access to a ...
0
votes
0answers
25 views
Calculate 70% of the area inside a polygon based on the polygon centroid
I am trying to generate an area within a polygon based on the polygons centroid that covers 70% of the containing polygons area. I generated the polygon centroids as points but I do not know how to ...
1
vote
0answers
39 views
What happens if some polygons are empty in reduce() in Google Earth Engine
I am drawing the NDVI time-series trend for two types polygon in my target area using Sentinel-2. I don't know why I miss one day's NDVI mean. Is it because some polygons are unmasked after cloudrmove?...
0
votes
1answer
25 views
Spatial join (points in polygon) but also including the “observation count” of each point in the join_count field
I have point layers of bird observations, and I want to symbolize certain areas by the number of bird observations in each polygon. Each point in the point layer has a "observation count" field ...
3
votes
2answers
292 views
Counting unique features of points inside polygon in QGIS
I have a series of points with various fields in the attribute table, including a car_id. I also have several polygons in which some of these points are located.
I want to count how many unique ...
2
votes
1answer
73 views
Creating new point features from count number of existing features using ArcMap
I have point features with coordinates, but some of those points have multiple observations at the same coordinate. I put those as a count column in the attribute table. But now I need to do a spatial ...
0
votes
0answers
16 views
Combining information from two shapefiles. One “point”, the other “polygon” [duplicate]
I have a dataset of survey location "clusters." There are about 2,000 clusters. I also have a dataset that shows Egypt's municipality boundaries. There are around 350 municipalities.
What I want to ...
2
votes
0answers
105 views
Point grid in QGIS
I'm working on a project that needs me to map out a point grid for drilling work.
The grid needs to fall within an already created polygon and be spaced 30x35meters. I was able to overlay a pointgrid ...
0
votes
0answers
8 views
How to count a point attribute inside polygons using R? [duplicate]
I saw a lot of answers about counting points inside polygons, but none of them is about counting some attribute of the points inside polygons.
I have a shapefile of some brazilian regions, and an ...
0
votes
1answer
27 views
Using weighted species distribution data to create a scored grid map
I'm currently working on a project within ArcGIS Pro, I have a large dataset (>40000 points) comprising a list of ~120 indicator species as point data that are assigned numerical scores (1-10) based ...
1
vote
2answers
142 views
Get waterbody info from base map in Leaflet
I am plotting points on a map using Leaflet, and would like to collect any data I can concerning the water bodies that encompass these points. I have been making use of polygons from HydroSHEDS (...
3
votes
0answers
123 views
Determine which points in a CSV are within a shapefile polygon using GDAL / OGR in Python [closed]
I have a csv file containing columns with latitude, longitude and some values, and a shapefile with a few polygons. Some of my points/rows in the CSV are within, and some outside the shapefile ...
0
votes
0answers
35 views
Extracting data from one grid cells to another set of grid cells
I have my own point shapefile (each point has its lats n longs). I found a data which has lats and longs, and I imported it into ArcMap and created a shapefile which also has its own points (with lats ...
2
votes
1answer
105 views
R {sp} spatial subset: keep so many polygons as number of overlapping points
I have a set of overlapping spatial points and spatial polygons. I need to subset the polygons by overlapping points, but, if my polygon contains 2 points, I need to keep polygon twice, etc.
To keep ...
4
votes
1answer
314 views
Snapping/moving points near polygon to inside polygon using QGIS
I have a set of polygons (buildings) and points that I'd like to spatially join. Unfortunately, some of these points are positioned outside the polygon because all points are positioned on the ...
3
votes
1answer
151 views
Invalid geometry in point layer when running 'Count points in polygon'
I have a persistent problem I can't seem to fix. I'm trying to run Count points in polygon. I keep getting this error:
Feature (747) has invalid geometry. Please fix the geometry or change the ...
1
vote
0answers
43 views
Random Points with Polygon ID
In QGIS 3.4, I would like to place random points inside each polygon using a field from an attribute in the polygon layer and tag each point with its polygon id. Currently, I use Random Points inside ...
2
votes
1answer
121 views
Extract maximum pixel value vertex from a raster for a given grid cell without altering the position of the source location in QGIS
I have a 0.5 X 0.5 metre resolution raster. I would like to extract the maximum value points from the raster for every 2 metre square cell. And the extracted points should be in the centre of the ...
5
votes
1answer
100 views
Referencing a polygon layer in the field calculator of a point layer to make a virtual field
I have a polygon layer that shows the counties of England and a point layer of project sites. I am trying to make a new virtual field within the point layer that will reference the county that it is ...
