This question is related to a post with a similar title (replace NA in an R vector with adjacent values). I would like to scan a column in a data frame and replace NA's with the value in the adjacent cell. In the aforementioned post, the solution was to replace the NA not with the value from the adjacent vector (e.g. the adjacent element in the data matrix) but was a conditional replace for a fixed value. Below is a reproducible example of my problem:
UNIT <- c(NA,NA, 200, 200, 200, 200, 200, 300, 300, 300,300)
STATUS <-c('ACTIVE','INACTIVE','ACTIVE','ACTIVE','INACTIVE','ACTIVE','INACTIVE','ACTIVE','ACTIVE',
'ACTIVE','INACTIVE')
TERMINATED <- c('1999-07-06' , '2008-12-05' , '2000-08-18' , '2000-08-18' ,'2000-08-18' ,'2008-08-18',
'2008-08-18','2006-09-19','2006-09-19' ,'2006-09-19' ,'1999-03-15')
START <- c('2007-04-23','2008-12-06','2004-06-01','2007-02-01','2008-04-19','2010-11-29','2010-12-30',
'2007-10-29','2008-02-05','2008-06-30','2009-02-07')
STOP <- c('2008-12-05','4712-12-31','2007-01-31','2008-04-18','2010-11-28','2010-12-29','4712-12-31',
'2008-02-04','2008-06-29','2009-02-06','4712-12-31')
TEST <- data.frame(UNIT,STATUS,TERMINATED,START,STOP) TEST
UNIT STATUS TERMINATED START STOP
1 NA ACTIVE 1999-07-06 2007-04-23 2008-12-05
2 NA INACTIVE 2008-12-05 2008-12-06 4712-12-31
3 200 ACTIVE 2000-08-18 2004-06-01 2007-01-31
4 200 ACTIVE 2000-08-18 2007-02-01 2008-04-18
5 200 INACTIVE 2000-08-18 2008-04-19 2010-11-28
6 200 ACTIVE 2008-08-18 2010-11-29 2010-12-29
7 200 INACTIVE 2008-08-18 2010-12-30 4712-12-31
8 300 ACTIVE 2006-09-19 2007-10-29 2008-02-04
9 300 ACTIVE 2006-09-19 2008-02-05 2008-06-29
10 300 ACTIVE 2006-09-19 2008-06-30 2009-02-06
11 300 INACTIVE 1999-03-15 2009-02-07 4712-12-31
#using the syntax for a conditional replace and hoping it works :/
TEST$UNIT[is.na(TEST$UNIT)] <- TEST$STATUS; TEST
UNIT STATUS TERMINATED START STOP
1 1 ACTIVE 1999-07-06 2007-04-23 2008-12-05
2 2 INACTIVE 2008-12-05 2008-12-06 4712-12-31
3 200 ACTIVE 2000-08-18 2004-06-01 2007-01-31
4 200 ACTIVE 2000-08-18 2007-02-01 2008-04-18
5 200 INACTIVE 2000-08-18 2008-04-19 2010-11-28
6 200 ACTIVE 2008-08-18 2010-11-29 2010-12-29
7 200 INACTIVE 2008-08-18 2010-12-30 4712-12-31
8 300 ACTIVE 2006-09-19 2007-10-29 2008-02-04
9 300 ACTIVE 2006-09-19 2008-02-05 2008-06-29
10 300 ACTIVE 2006-09-19 2008-06-30 2009-02-06
11 300 INACTIVE 1999-03-15 2009-02-07 4712-12-31
The outcome should be:
UNIT STATUS TERMINATED START STOP
1 ACTIVE ACTIVE 1999-07-06 2007-04-23 2008-12-05
2 INACTIVE INACTIVE 2008-12-05 2008-12-06 4712-12-31
3 200 ACTIVE 2000-08-18 2004-06-01 2007-01-31
4 200 ACTIVE 2000-08-18 2007-02-01 2008-04-18
5 200 INACTIVE 2000-08-18 2008-04-19 2010-11-28
6 200 ACTIVE 2008-08-18 2010-11-29 2010-12-29
7 200 INACTIVE 2008-08-18 2010-12-30 4712-12-31
8 300 ACTIVE 2006-09-19 2007-10-29 2008-02-04
9 300 ACTIVE 2006-09-19 2008-02-05 2008-06-29
10 300 ACTIVE 2006-09-19 2008-06-30 2009-02-06
11 300 INACTIVE 1999-03-15 2009-02-07 4712-12-31
It didn't work because status was a factor. When you mix factor with numeric then numeric is the least restrictive. By forcing status to be character you get the results you're after and the column is now a character vector:
TEST$UNIT[is.na(TEST$UNIT)] <- as.character(TEST$STATUS[is.na(TEST$UNIT)])
## UNIT STATUS TERMINATED START STOP
## 1 ACTIVE ACTIVE 1999-07-06 2007-04-23 2008-12-05
## 2 INACTIVE INACTIVE 2008-12-05 2008-12-06 4712-12-31
## 3 200 ACTIVE 2000-08-18 2004-06-01 2007-01-31
## 4 200 ACTIVE 2000-08-18 2007-02-01 2008-04-18
## 5 200 INACTIVE 2000-08-18 2008-04-19 2010-11-28
## 6 200 ACTIVE 2008-08-18 2010-11-29 2010-12-29
## 7 200 INACTIVE 2008-08-18 2010-12-30 4712-12-31
## 8 300 ACTIVE 2006-09-19 2007-10-29 2008-02-04
## 9 300 ACTIVE 2006-09-19 2008-02-05 2008-06-29
## 10 300 ACTIVE 2006-09-19 2008-06-30 2009-02-06
## 11 300 INACTIVE 1999-03-15 2009-02-07 4712-12-31
You have to do
TEST$UNIT[is.na(TEST$UNIT)] <- TEST$STATUS[is.na(TEST$UNIT)]
so that the value will be replaced with the adjacent value. Otherwise there is a mismatch between the number of values to be replaced and the values to replace them with. This would result in the values being replaced in row order. It works in this case because the two values being replaced are the first two.
来源：https://stackoverflow.com/questions/15629885/replace-na-in-column-with-value-in-adjacent-column