Dear R-Sig-Geo Members,
??? I've like to extract xy coordinates from raster of 24 neigborhood
cells that surround the 4 given points (pts_s) pixels and for this I used:
#Packages
require(raster)
require(sp)
## Create a raster
r <- raster(nc=30, nr=30)
r <- setValues(r, round(runif(ncell(r))* 255))
plot(r)
##Given interesting points coordinates
xd???? <- c(-24.99270,45.12069,99.40321,73.64419)
yd? <- c(-45.435267,-88.369745,-7.086949,44.174530)
pts <- data.frame(xd,yd)
pts_s<- SpatialPoints(pts)
points(pts_s, col="red", pch=16)
## Find pixels center of each point (My idea is not to use the original
point coordinates, but coordinates of the center of interesting pixel).
N_cells <- cellFromXY(r, pts_s)
# Extract xy coordinates from raster of 24 neighborhood cells given
pixel number N_cells
e<-adjacent(r, N_cells , directions='bishop', id=TRUE)
coordinates(land_mask)[e[,1],] ## Doesn't return 24 neighborhood by
N_cells object
ng_coords<-coordinates(land_mask)[e[,1],]
#
#Visualization
plot(r)
points(pts_s, col="red", pch=16)
points(ng_coords, col="black", pch=16)
##
??? But I don't have success because the ng_coords object is not a 24
neighborhood cells of each point that I search. There are solution for this?
Thanks in advance,
Alexandre
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Alexandre dos Santos
Prote??o Florestal
IFMT - Instituto Federal de Educa??o, Ci?ncia e Tecnologia de Mato Grosso
Campus C?ceres
Caixa Postal 244
Avenida dos Ramires, s/n
Bairro: Distrito Industrial
C?ceres - MT CEP: 78.200-000
Fone: (+55) 65 99686-6970 (VIVO) (+55) 65 3221-2674 (FIXO)
alexandre.santos at cas.ifmt.edu.br
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OrcID: orcid.org/0000-0001-8232-6722
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