(M<-mondate.mdy(12,31,2001:2003))
mean(M) # the middle value, Dec. 31, 2002
(M<-c(M,mondate.mdy(12,31,2004))) # tack on another yearend
mean(M) # mid-year 2003
mean(M,12) # 12 is coerced to Dec. 31, 2000, so the
# mean is again Dec. 31, 2002
x <- mondate.ymd(2001:2005,12) # five year ends
y <- x-12 # one year earlier
pmean(x,y) # 2001-06-30 ... 2005-06-30
unique(M,M) # just M
(M<-matrix(M,nrow=2)) # now a matrix
rbind(M,M) # 2 M's, stacked
unique(rbind(M,M)) # M again, still a matrix
m <- mondate.ymd(2013, 1:12) # end of the months of 2013
quarters(m)
Run the code above in your browser using DataCamp Workspace