R：删除重复的条目，如果它们在一年内到来-R:removingduplicatedentriesiftheycomewithinayear

Im new to R, I have a data frame of 500000 entries of patient IDs and dates and other variables..

我是R的新手,我有一个500000条患者ID和日期以及其他变量的数据框。

I want to remove any repeated duplicated patient ID(PtID) if they happen to come within one year of their first appearance.. for example:

我想删除任何重复的重复患者ID(PtID),如果它们恰好在他们第一次出现后的一年内...例如:

 PtID    date**
 1. 1    01/01/2006
 2. 2    01/01/2006
 3. 1    24/02/2006 
 4. 4    26/03/2006
 5. 1    04/05/2006
 6. 1    05/05/2007

in this case I want to remove the 3rd and the 5th rows and keep the 1st and 6th rows..

在这种情况下,我想删除第3行和第5行并保留第1行和第6行..

can somebody help me with this please.. this is the str(my data which is called final1)

请有人帮我这个..这是str(我的数据叫做final1)

str(final1)
'data.frame':   605870 obs. of  70 variables:
...
 $ Date          : Date, format: "2006-03-12" "2006-04-01" ...
$ PtID          : int  11251 11251 11251 11251 11251 11251 11251 30938 30938 11245 ...
...

1 个解决方案

require(plyr)
require(lubridate)

num = 1:6
PtID = c(1,2,1,4,1,1)
date = c("01/01/2006", "01/01/2006","24/02/2006", "26/03/2006", "04/05/2006",
  "05/05/2007")
dd = data.frame(PtID, date)

dd$date = dmy(date)

keepId = function(dates) {
  keep = ((dates - min(dates)) > 365*24*60*60) |
  ((dates == min(dates)))
  return(keep)
}

dd_sub = ddply(dd, c("PtID"), transform, keep = keepId(date))
dd_sub[dd_sub$keep,]