[R] correcting a few data in an unreshaped data frame

[Joris Meys]

Use indices.

Eg:
# a sample dataframe
lupepn1 <- data.frame(
  bushno=rep(1:2,4),
  bout=rep(1:4,each=2),
  survival=rep(0,8),
  wwg=rep(1,8)
)
lupepn1
# select the wrong cases
wrong <- lupepn1$bushno==1 & lupepn1$bout %in% c(1,2)

# make a replacement frame
replacement <- rbind(c(4,5),c(9,10))

# do the replacement
lupepn1[wrong,c("survival","wwg")] <- replacement
lupepn1

Cheers
Joris

On Wed, Jun 9, 2010 at 3:36 AM, Mr. Natural <drstrong at ucdavis.edu> wrote:
>
> Thanks for the excellent help on my recent question on this topic in which
> the data frame had been reshaped by cast.
> Now, I would like to access and change erroneous data in a data frame that
> has not been reshaped.
>
> The file is lupepn1, with identifier variables bushno & bout and
> dependent variables survival, and wwG
> I know the bushno and bout of the erroneous dependent survival and wwG data.
> I could correct these in the csv file before read.data, but I would like to
> learn some more R
>
> head(lupepn1)
>  bushno bout survival wwG
> 2      1    2        0   0
> 3      1    3        0   0
> 4      1    4        0   0
> 5      1    5        0   0
> 6      1    6        0   2
> 7      1    7        0   0
>
>> str(lupepn1)
> 'data.frame':   5023 obs. of  4 variables:
>  $ bushno  : int  1 1 1 1 1 1 1 2 2 2 ...
>  $ bout    : int  2 3 4 5 6 7 8 1 2 3 ...
>  $ survival: int  0 0 0 0 0 0 0 1 1 1 ...
>  $ wwG     : int  0 0 0 0 2 0 0 5 1 0 ...
>  - attr(*, "na.action")=Class 'omit'  Named int [1:81] 1 49 65 177 201 257
> 337 417 449 505 ...
>  .. ..- attr(*, "names")= chr [1:81] "1" "49" "65" "177" ...
>
> Your kind advice is very much appreciated.
> Mr. Natural.
>
>>
>
>
> --
> View this message in context: http://r.789695.n4.nabble.com/correcting-a-few-data-in-an-unreshaped-data-frame-tp2248219p2248219.html
> Sent from the R help mailing list archive at Nabble.com.
>
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> and provide commented, minimal, self-contained, reproducible code.
>



-- 
Joris Meys
Statistical consultant

Ghent University
Faculty of Bioscience Engineering
Department of Applied mathematics, biometrics and process control

tel : +32 9 264 59 87
Joris.Meys at Ugent.be
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