Questions tagged [point-in-polygon]
A common GIS operation. Used to determine whether a point lies within a polygon's bounds.
307
questions
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25 views
Intersection point and polygon layer [closed]
I have a .csv with a column for ID, latitude, and longitude, which creates points. I also have a .shp file which creates polygons of a parcel. I want to be able to attribute the polygon to the point. ...
4
votes
1answer
65 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 ...
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0answers
31 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
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1answer
29 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 ...
1
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1answer
28 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 ...
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7 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....
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0answers
20 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
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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
33 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
27 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 ...
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0answers
18 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
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0answers
46 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 ...
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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
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0answers
36 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
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1answer
23 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
203 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
61 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
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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 ...
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0answers
46 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 ...
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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
24 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
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2answers
104 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 (...
2
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0answers
90 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
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0answers
33 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
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1answer
84 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
195 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
92 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
40 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
92 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
65 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 ...
2
votes
1answer
51 views
Add multiple points correctly distributed within a polygon
I'm a little new using QGIS.
I know how to add random points within a geometry but how can I add multiple correctly distributed points within a polygon?
Like this
Not Like this
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0answers
60 views
Determine in Python if point is within a WGS84 polygon intersecting 180th meridian
I have a Python list of WGS84 points. Connecting these points together, we get two polygons on the WGS84 model of the Earth. I am interested in the smaller polygon which can possibly intersect 180th ...
3
votes
1answer
496 views
Counting number of points in each grid?
I would like to count the number of points in each cell. I have tried https://docs.scipy.org/doc/numpy/reference/generated/numpy.histogram2d.html but the out isn't appropriate. Does anybody know how I ...
1
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0answers
68 views
Can I make PostGIS treat polygon edges like Google Earth does?
Consider the following geographic polygon in PostGIS:
POLYGON((60 -60,60 -50,179 -50,179 -60,60 -60))
The smallest latitude is -60, so initially I expected any point with a latitude less than -60 to ...
1
vote
1answer
46 views
Exracting data fromSpatialPolygonDataFrame conditionally in R?
For some research I am working on, I have a dataframe called charters of charter schools in New Jersey. Simplified it looks like this:
school.name school.id district.id lat ...
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0answers
37 views
Point and Polygon Intersection [closed]
I have a .csv with a column for ID, latitude, and longitude, which creates points. I also have a .shp file which creates polygons of a parcel. I want to be able to attribute the polygon to the point. ...
1
vote
1answer
61 views
Point.in.polygon function in sf package miscalculate the distribution of points
I am using point.in.polygon function in sf package to determine whether a set of data fall within a polygon or not.
Here is a snippet of the data and polygon visualization
As the figure shows, there ...
2
votes
0answers
42 views
Using multiple fields for random points in polygons QGIS?
I'm quite new to QGIS and I have a question about the 'random points in polygons' functionality.
Is it possible to use more than one field from the attibute table when using 'random points in ...
3
votes
2answers
144 views
Calculate the travel time from locations to the closest N points
I want to calculate the travel time (based on walking time) from locations to the closest N points of another dataset. Then I want to create a hull around those N closest points per location
Is this ...
0
votes
0answers
20 views
Splitting a layer containing multiple polygons into multiple layers each containing one polygon [duplicate]
So firstly, I used the buffer tool in Qgis3 to create (twenty) polygons with a certain width from (twenty) points.
This lead to the situation below, where o1 and o2 are two original points and 1 and 2 ...
1
vote
0answers
98 views
Does spatial indexing speed batch Point in Polygon
I have two tables, one with 66 thousand points and other with 5.5 thousand polygons. I'm trying to correlate which point is in which polygon and it is taking a long time. I want to know if spatial ...
0
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0answers
33 views
What analysis tool I can use to identify the relation between points and areas
I want a binary result for each purple point in this map, i.e. whether in or out od the blue polygon areas?
In this case, one is in and the other is out. What analysis tool in ArcGIS Pro (also arcpy ...
0
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0answers
12 views
Assigning polygons to a feature class
I understand there’s a way or a program that can assign polygons (precincts) to a feature point.(Vote Centers)
For insistence the law states we need to assign a maximum of 10 precincts (or polygons) ...
1
vote
1answer
406 views
MULTIPOINT Text to list of POINT objects
I need to convert a MULTIPOINT string to a list of POINT objects. For example, suppose I have a query with ST_AsText() producing an output that is captured in my_points:
>>>print(my_points)
...
0
votes
1answer
364 views
Identify polygon grid in which the point belongs to?
I have a dataframe with 3 columns , which has my custom lat / long with a failure rate associated with each Lat / long
head(df)
Latitude Longitude Failure.rate
51.3 ...
2
votes
1answer
43 views
Spatial adaption of points to polygons [duplicate]
I have a point layer for the cold air flow in specific region. I would like to simplify all the single points to a polygon shape as to be able to join the data with other spatial data. My way is ...
0
votes
0answers
158 views
Identify features problem in QGIS
I am using QGIS 2.18 to identify points that fall out of a specific boundary but the identify features is not working. When I right click, it brings me the polygon feature. So i turned off the polygon ...
1
vote
0answers
124 views
Uncompressed vs Subdivided: which one offers better PostGIS INTERSECTS performance?
In my PostGIS I have a point table (roughly 51 millions rows) and a multipolygon table. I need to find a polygon label/ID for every single point in my point table (roughly 51 millions rows) in PostGIS....
4
votes
2answers
1k views
Combining st_join with st_nn to include all points within, as well as within a given distance of a polygon
This is a follow up to my earlier question (Spatial join in R - Adding points to polygons with multiple corresponding points).
I have successfully joined a spatial points file to a polygon file in R ...
1
vote
1answer
154 views
Simple point in polygon query at PostGIS & PostgreSQL
Using PostGIS & PostgreSQL (Amazon RDS instance), I need to create a (quite large) table with points (just x, y coordinates)
Then what I need to do is very simple point-in-polygon queries. Points ...
