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How to extract intersection areas in shapefile 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.
How to intersect a polygon with a point in R?
I am working with shapefiles in R, one is point.shp the other is a polygon.shp. Now, I would like to intersect the points with the polygon, meaning that all the values from the polygon should be attached to the table of the point.shp. I tried overlay () and spRbind in package sp, but nothing did what I expected them to do.
How to combine polygons and points in R-stack?
If you do overlay (pts, polys) where pts is a SpatialPointsDataFrame object and polys is a SpatialPolygonsDataFrame object then you get back a vector the same length as the points giving the row of the polygons data frame. So all you then need to do to combine the polygon data onto the points data frame is: HOWEVER!
What’s the difference between gintersection and intersect in R?
The “intersect” function uses the overlapping extents whereas, “gIntersection” is the explicit intersection of the vector geometries. The intersect approach is a square/rectangular intersection and not an intersection of the actual polygons.
How to open a shapefile directly in R?
You can use sf library to open Shapefiles directly in R. It’s faster than rgdal library, check here: Simple Features for R – Benchmarks. For further information about the sf package check the project homepage r-spatial. # Load library library (‘sf’) # Load shapefile shapename <- read_sf (‘~/path/to/file.shp’)
How to use rgdal on an ESRI shapefile?
If that looks like a hassle to you, rgdal will make it easy by reading the ESRI shapefile’s .prj file (the file that contains ESRI’s projection definition for the shapefile. To use rgdal on the same file you would simply write:
How to check if points fall within polygon shapefile?
Pascal’s answer almost covers it but you may need two extra steps as below. I used a similar approach to the accepted answer in this post but was never really satisfied with it so I looked into alternatives and found the sf library. Thanks for contributing an answer to Geographic Information Systems Stack Exchange!
What’s the fastest way to intersect a polygon?
Consider using Rtree to help identify which grid cells that a polygon may intersect. This way, you can remove the for loop used with the array of lat/lons, which is probably the slow part.
How do you create grid cells in shapely?
Currently, I am creating the polygons and the grid cells using shapely (based on their corner coordinates). Then, using a simple for-loop I go through each polygon and compare it to nearby grid cells. Just a small example to illustrate the polygons/grid cells.
How long does it take to run polygon intersection in Python?
However, running this code on a huge amount of polygons (each one could intersect dozens of grid cells) takes around 15+ minutes (up to 30+ min depending on the number of intersecting grid cells) on my machine which is not acceptable.
What happens when you intersect two polygons in ArcGIS?
The graphic below illustrates the result of intersecting two polygon feature classes with the Output Type parameter set to POINT. The output point features are where a polygon from one of the input feature classes has a vertex intersecting the boundary (intersect at a point) of a polygon from the other input feature class.
How to calculate overlap between Polygon and shapefile?
If you have the shape of both polygons. You can do something like the following: Of course, I’m oversimplifying the problem and the result most probably is with euclidian area which might not be what you need. Thus said, for the area of a polygon on the surface of a sphere you can verify code from the following reference.