r

http://vgoulet.act.ulaval.ca/en/emacs/mac/

mean() 均值

sd()标准差

http://www.walware.de/it/downloads/statet.mframe
data()
hist()
list(u=2,v='abc')
str() #structure
lm()
summary()
plot()

help(seq) # ?seq
help.search(xx) # ??xx
read.table("data.txt")
class() #view type like str()
attributes()
example("seq")