R scripts

R-scripts to deal with netCDF files, perform downscaling and compute 19 bioclimatic variables are available at github.com/ecoClimate.

Explore them and advance your limits on new variables.

Here you have an R-script for opening ecoClimate.org layers in R. Our climatic layers are stored as *.txt* files. Thus, you need to open them using the function read.table and then construct raster files (maps) as follows:

1. download the climatic layers (.txt files) from ecoClimate.org

2. save them in a folder in your computer and use the function ‘setwd’ to set this folder as the working directory

3. open the file in R using ‘read.table’

setwd("Path/Of/Folder/With/Climatic/Layers")

CCSM_LGM <- read.table("FileName.txt", header = TRUE)

head(CCSM_LGM)

4. load the libraries to work with GIS formats in R, (install them first if you do not have them in your computer; use the function ‘install.packages’)

library(sp)

library(raster)

5. Run this simple code in order to construct raster files for each climatic layer

gridded(CCSM_LGM) <- ~long+lat

map_CCSM_LGM <- stack(CCSM_LGM)

6. Finally, you can plot the raster files using your own palette of colours

colores_t <- colorRampPalette (c("darkblue", "blue",

            "lightblue", "white", "salmon", "red"))

in this example, we are plotting the temperature variables (thus, we select the maps 2 to 12))

plot (map_CCSM_LGM [[c(2:12)]], axes=F, box=F, col=colores_t (100))

here, we use $ in order to select one specific variable (e.g., bio.1)

par (mar=c(1,1,1,1))

plot (map_CCSM_LGM$bio.1, axes=F, box=F, col=colores_t(100), legend=T)

title ("LGM Bio1 CCSM")

now, we are going to change the colours because we want to plot the precipitation layers (13 to 20)

colores_p <- colorRampPalette (c("white","lightblue","blue", "darkblue"))

plot (map_CCSM_LGM [[c(13:20)]], axes=F, box=F, col=colores_p (100))

we hope that this R-script will help you to understand how to easily work in R with raster files
Best,
Sara Varela and Matheus Lima-Ribeiro