Graham,
# use dput() to share your data in a way that's easy for R-help readers to
use
mydf <- structure(list(dn = c(4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L,
4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L), obs = c(1L, 1L, 1L, 1L,
1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 3L, 4L),
choice = c(0L, 0L, 0L, 0L, 0L, 1L, 0L, 0L, 1L, 0L, 0L, 0L,
0L, 0L, 0L, 0L, 0L, 1L, 0L), acid = c("LOSEC", "NEXIUM",
"PARIET", "PROTIUM", "ZANTAC", "ZOTON", "LOSEC", "NEXIUM",
"PARIET", "PROTIUM", "ZANTAC", "ZOTON", "LOSEC", "NEXIUM",
"PARIET", "PROTIUM", "ZANTAC", "ZOTON", "LOSEC"), br = c(1L,
2L, 3L, 4L, 5L, 6L, 1L, 2L, 3L, 4L, 5L, 6L, 1L, 2L, 3L, 4L,
5L, 6L, 1L), cdate = c(NA, NA, NA, NA, NA, "23-Aug-00", NA,
NA, "25-Sep-00", NA, NA, NA, NA, NA, NA, NA, NA, "20-Sep-00",
NA), situation = c(NA, NA, NA, NA, NA, "NS", NA, NA, "L",
NA, NA, NA, NA, NA, NA, NA, NA, "R", NA), mth = c(NA, NA,
NA, NA, NA, 487L, NA, NA, 488L, NA, NA, NA, NA, NA, NA, NA,
NA, 488L, NA), year = c(NA, NA, NA, NA, NA, 2000L, NA, NA,
2000L, NA, NA, NA, NA, NA, NA, NA, NA, 2000L, NA), set = c(1L,
1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L,
3L, 3L, 4L)), .Names = c("dn", "obs", "choice", "acid", "br",
"cdate", "situation", "mth", "year", "set"), class = "data.frame",
row.names = c("1",
"2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13",
"14", "15", "16", "17", "18", "19"))
# use aggregate() to calculate the mean of mth for each combination of dn
and obs
mean.mth <- aggregate(mth ~ dn + obs, data=mydf, mean, na.rm=TRUE)
# merge the original data with means
mydf2 <- merge(mydf, mean.mth, by=c("dn", "obs"), suffixes=c("",".filled"))
Jean
On Sat, Apr 6, 2013 at 4:24 AM, GRAHAM LEASK <grahamle...@btopenworld.com>wrote:
>
>
> I have a large dataset organised in choice groups see below. Each choice
> represents a separate occasion with 1 product chosen out of the 6 offered.
>
>
>
>
> +-------------------------------------------------------------------------------------------------+
> | dn obs choice acid br date cdate
> situat~n mth year set |
>
> |-------------------------------------------------------------------------------------------------|
> 1. | 4 1 0 LOSEC 1 .
> . . . 1 |
> 2. | 4 1 0 NEXIUM 2 .
> . . . 1 |
> 3. | 4 1 0 PARIET 3 .
> . . . 1 |
> 4. | 4 1 0 PROTIUM 4 .
> . . . 1 |
> 5. | 4 1 0 ZANTAC 5 .
> . . . 1 |
>
> |-------------------------------------------------------------------------------------------------|
> 6. | 4 1 1 ZOTON 6 23aug2000 01:00:00
> 23aug2000 NS 487 2000 1 |
> 7. | 4 2 0 LOSEC 1 .
> . . . 2 |
> 8. | 4 2 0 NEXIUM 2 .
> . . . 2 |
> 9. | 4 2 1 PARIET 3 25sep2000 01:00:00
> 25sep2000 L 488 2000 2 |
> 10. | 4 2 0 PROTIUM 4 .
> . . . 2 |
>
> |-------------------------------------------------------------------------------------------------|
> 11. | 4 2 0 ZANTAC 5 .
> . . . 2 |
> 12. | 4 2 0 ZOTON 6 .
> . . . 2 |
> 13. | 4 3 0 LOSEC 1 .
> . . . 3 |
> 14. | 4 3 0 NEXIUM 2 .
> . . . 3 |
> 15. | 4 3 0 PARIET 3 .
> . . . 3 |
>
> |-------------------------------------------------------------------------------------------------|
> 16. | 4 3 0 PROTIUM 4 .
> . . . 3 |
> 17. | 4 3 0 ZANTAC 5 .
> . . . 3 |
> 18. | 4 3 1 ZOTON 6 20sep2000 00:00:00
> 20sep2000 R 488 2000 3 |
> 19. | 4 4 0 LOSEC 1 .
> . . . 4 |
>
> I wish to fill in the missing values in each choice set delineated by dn
> (Doctor) obs (Observation number) and choices (1 to 6).
> For each choice set one choice is chosen which contains full time
> information for that choice set ie in set 1 choice 6 was chosen and
> shows the month 487. The other 5 choices show mth as missing. I want to
> fill these with the correct mth.
>
> Clearly on different occasions the date will differ but each choice set
> has only one date.
>
> Is there a simple elegant way to do this in R?
> Kind regards
>
>
>
>
> Graham
> [[alternative HTML version deleted]]
>
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
>
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