I am trying to create a map from raster data. The file came from a crop model, with resolution of 0.5 degree. Even when I disaggregate it (i.e. increase spatial resolution), the map looks really pixelated. I am trying to make it look better.
My current code produces this image:
where I would like to "smooth" the data, by supressing the pixelated look. Some other visualization programs do this automatically, so I guess it should not be hard to reproduce using R.
For example, this is the same file plotted using Panoply:
It doesn't look absolutely smooth, but at least it doesn't have the pixelated look neither. How to achieve a similar result in R?
This is the code to reproduce my problem:
library(RCurl) library(rasterVis) # Go to temp dir and download file - approx. 1.7M old <- setwd(tempdir()) # download raster and shapefile download.file('https://dl.dropboxusercontent.com/u/27700634/yield.nc', 'yield.nc', method='curl') download.file('https://dl.dropboxusercontent.com/u/27700634/southern.zip', 'southern.zip', method='curl') unzip('southern.zip', exdir='.') # load southern Brazil shapefile mapaSHP <- shapefile('southern.shp') # load brick b <- brick('yield.nc', level=16) # create color scheme mycols <- rasterTheme(region=colorRampPalette(brewer.pal(9,'Greens'))(100)) # use second brick layer to plot map levelplot(b[], margin = FALSE, main = "Rice yield in tons/ha", par.settings = mycols) + layer(sp.lines(mapaSHP, lwd=0.8, col='darkgray')) # return to your old dir setwd(old)