All Questions
45
questions
0
votes
1
answer
74
views
I need spatial polygons representing the land and sea in a world map and then convert them to a dataframe
I need a world map in R that can be transformed into polygons of land to be able to calculate distances through sea from one point to another and going around land/polygons. These polygons need to be ...
0
votes
1
answer
78
views
'unable to find an inherited method for function ‘costDistance’ for signature' error while trying to do a friction weighted connectivity analysis
The purpose
What I am trying to achieve: I am trying to calculate the friction weighted connectivity values of the polygons in a shapefile using a friction raster. The shapefiles symbolize habitats ...
0
votes
1
answer
63
views
How to preserve holes when combining contours into polygons via R?
Part of the workflow for my project requires creating contours from a raster. I am able to generate the contours using raster::rasterToContour and can convert to a polygon using the sf package in R, ...
- 15
0
votes
1
answer
108
views
Error with M values and st_zm function in sf package
I have imported a multipolygon shp file containing different forest patches (called 'patch'):
patch
Then, I have bricked different Sentinel-2 bands for the same region in a raster called 'SenBel'
data:...
- 15
0
votes
2
answers
112
views
how to extract multiple polygon in r
Use this code below to give the mean of each district and this link CHIRPS tar.gz data, for precipitation data, library(geodata) for administrative districts.
library(sf)
library(raster)
# library(...
- 1
0
votes
0
answers
84
views
Create non-circular buffer around points (Spatial R)
I have some data that exist in a waterway system river network, and I'm trying to draw a buffer around some points, to see which areas of the water lie within a 10km boat ride.
library(raster)
library(...
- 887
3
votes
0
answers
292
views
Is it possible to create an irregular raster in R with terra package?
I have a dataset which represents a global grid with latitude and longitude and the length of each pixel along the x and y axis. These are simply lat/long CRS.
Like this
head(latlong)
x y ...
- 1,523
0
votes
3
answers
94
views
Jaccard index: R not letting me convert raster to numeric?
I'm trying to calculate the Jaccard index for my data, which is for two presence/absence rasters (of two different species). I also have a third raster, that contains the overlap of the species ranges....
1
vote
1
answer
1k
views
How to extract the mean raster value for a polygon based on matching a layer from a raster stack in R
Apologies for my naivety (and general incompetence), first time asking a question here and I'm not particularly good at R.
I have tried to provide a reproducible example below.
I have a stack of 365 ...
- 63
1
vote
0
answers
51
views
How can remove wrapline while buffering with sf package in r
How can I remove the crossing line while using the buffer code below. I tried to create buffers round some point locations and to have a union but ended up getting a crossline.
Please see the codes ...
1
vote
1
answer
775
views
How to find the area of intersections with raster/terra based methods and memory constraints in R?
I am trying to find the area of forest (conserved patches) around crop fields. For example, I would like to know the area of forest within a 500m or 5km radius from fields within a county. My data is ...
- 55
0
votes
1
answer
371
views
R stars::st_as_sf( , merge = TRUE) not working properly with Raster - Points with same values are not all merged
I have been trying to polygonize a raster in R and ran into memory issues. Searching for solutions, I found this question with a routine using the stars package in R that I felt could solve my issues. ...
- 55
0
votes
1
answer
384
views
Group raster files by week/month
I have downloaded AOD data ("MCD19A2") using the MODIStsp package for several years.
library(raster)
library(stars)
The data I have extracted has the following format:
...
- 23
2
votes
1
answer
312
views
Issue plotting generated polygon grid to leaflet
I am trying to create a polygon grid to plot in leaflet, but am running into an error that I cannot seem to figure out:
library(leaflet)
library(raster)
library(sf)
library(rgdal)
r <- raster(ext =...
- 127
0
votes
2
answers
676
views
exactextractr in R , Error: [names<-] incorrect number of names
Used exactextractr package (CRAN link) already and it always worked : I have a raster stack (s) and cut out with a shape-file (INV) like this
df1 <- exact_extract(s, INV, fun = c("mean", &...
