I would like to plot a raster in WGS84 projection using R based on its attribute value.
Here is the whole procedure
library(maptools)
library(rgdal)
library(raster)
shp <- readOGR("final_result.shp")
cell_size <- 0.012
lon_min <- 10.8; lon_max <- 18.2; lat_min <- 42; lat_max <- 48
ncols <- ((lon_max - lon_min)/cell_size)+1; nrows <- ((lat_max - lat_min)/cell_size)+1
snap1 <- raster(nrows=nrows, ncols=ncols, xmn=lon_min, xmx=lon_max, ymn=lat_min, ymx=lat_max, res=0.012, crs="+proj=longlat +datum=WGS84")
snap2 <- raster(nrows=nrows, ncols=ncols, xmn=lon_min, xmx=lon_max, ymn=lat_min, ymx=lat_max, res=0.012, crs="+proj=longlat +datum=WGS84")
snap1v <- shp[shp$snap == 1,]
print(snap1v)
class : SpatialPolygonsDataFrame
features : 1
extent : 10.9809, 18.18933, 42.07696, 47.89763 (xmin, xmax, ymin, ymax)
coord. ref. : +proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0
variables : 8
names : snap,CO,NH3,NOx,SOx,PM25,PM10,VOC
min values : 1, 0.0510012180001,0,1.25426065201,1.671099876,0.049, 0.0735,0
snap2v <- shp[shp$snap == 2,]
r_snap1 <- rasterize(snap1v, snap1, fields=c("CO", "NH3", "NOx", "SOx", "PM25", "PM10", "VOC"))
And description of the raster file:
r_snap1
class : RasterLayer
dimensions : 500, 617, 308500 (nrow, ncol, ncell)
resolution : 0.012, 0.012 (x, y)
extent : 10.9809, 18.18933, 42.07696, 47.89763 (xmin, xmax, ymin, ymax)
coord. ref. : +proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0
data source : in memory
names : layer
values : 1, 1 (min, max)
attributes :
ID snap CO NH3 NOx SOx PM25 PM10 VOC
1 1 0.05100122 0 1.254261 1.6711 0.049 0.0735 0
How can I plot the attribute value e.g. CO?
Just using plot(r_snap1) plots value 1 (ID).
Best Answer
How silly of me. Just found the answer:
You only need to add y value