It is not entirely clear what type of transformation you are trying to do.
Can you provide some sample data and then show what you would expect the
output to look like; make sure the data covers all the cases you want to
transform.

On Sat, Mar 13, 2010 at 8:54 PM, Junqian Gordon Xu <xjqian@gmail.com> wrote:

> I have a multilevel dataframe (df):
>
>   ID             Date      Segment Slice Tract     Lesion
> 1 CSPP005 12/4/2007       1     1      LCST         0
> 2 CSPP005 12/4/2007       1     1      LPC           2
> 3 CSPP005 12/4/2007       1     1      RPC          3
> 4 CSPP005 12/4/2007       1     1      RCST        1
> 5 CSPP005 12/4/2007       1     1      LGM          0
> 6 CSPP005 12/4/2007       1     1      RGM          0
> 7 CSPP005 12/4/2007       1     1      Whole        NA
>
> The five levels are:
>
> ID->Date->Segment->Slice->Tract
>
> The observation variable is: Lesion
>
> What I want to do is (in pseudo code)
>
> if  (any of the Tract (for a given ID, Date, Segment, and Slice),
> which( Lesion == 2) )
>    df [ for that particular (ID, Date,Segment, and slice) ,
> which(Tract == Whole) ] $Lesion <- 2
> else
>    df [ for that particular (ID, Date,Segment, and slice) ,
> which(Tract == Whole) ] $Lesion <- 0
>
>
>
> I started with (don't know if this is the right path),
>
> Lesion2<-df[which(df$Lesion == 2),]
> Where.Lesion2<-unique(Lesion2[,1:4])
> Whole<-subset(df, Tract == "Whole")
>
> But stuck at how to match the ID/Date/Segment/Slice from Where.Lesion2 to
> Whole.
>
> Regards
> Gordon
>
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> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html<http://www.r-project.org/posting-guide.html>
> and provide commented, minimal, self-contained, reproducible code.
>



-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?

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