1. aggregate: Split the data into subsets, computers summary statistics for each, and returns the result in a convenietn from. 
e.g. aggregate (Prec~year,data=Fort,max)
2. “~”在R中表示自变量和因变量
3. cdo yearsum -selmon,6,7,8 cdo   yearmean -shifttime,-2mo -selmon,9,10,11,12 ifile ofile 4. 插值到2.5x2.5: cdo remapbil,r144x73 infile1 infile2。主要144=360/2.5,而73=180/2.5+1
5.  # The palette with grey: cbPalette <- c("#999999", "#E69F00", "#56B4E9", "#009E73", "#F0E442", "#0072B2", "#D55E00", "#CC79A7") #