[R] Filling in empty arrays/lists from using "paste" function

[Uwe Ligges]

I highly suggest to rethink your problem in a way that you store the 
things labelled, e.g., TA1 to TA5 (as well as all the others) as the 
elements of a list TA. This way you have just one object TA that can 
easily be accessed by index operations and the code looks much cleaner 
in the end.

Best,
Uwe Ligges


Steven Kang wrote:
> Dear R users,
> 
> I am trying to fill in arrays (5 different according to distinct "id")
> from objects produced from arbitrary data set below.
> 
>   a <-
> data.frame(id=rep(c("idA1","idA2","idA3","idA4","idA5"),2),pro=c("bb","uu","ee","tt","uu","gg","tt","bb","gg","ee"),sal=rpois(10,2))
> 
>       id    pro sal
> 1  idA1  bb   2
> 2  idA2  uu   0
> 3  idA3  ee   3
> 4  idA4  tt   2
> 5  idA5  uu   4
> 6  idA1  gg   3
> 7  idA2  tt   0
> 8  idA3  bb   1
> 9  idA4  gg   0
> 10 idA5  ee   5
> My desired outputs (5 arrays/lists classified according to distinct "id"
> field) are as follow:
> 
>> TA1
> bb ee gg tt uu
>  2  0  3  0  0
> 
>> TA2
> bb ee gg tt uu
>  0  0  0  0  0
> 
>> TA3
> bb ee gg tt uu
>  1  3  0  0  0
> 
> ...... similarly for TA4 & TA5.
> 
> The above results were produced using TA1 <-
> c(bb=TA1.bb,ee=TA1.ee,gg=TA1.gg,tt=TA1.tt,uu=TA1.uu), TA2 <-
> c(bb=TA2.bb,ee=TA2.ee,gg=TA2.gg,tt=TA2.tt,uu=TA2.uu*)* etc for TA3~TA5.
> Although these generate the output I desire, I would like to use a single
> statement for producing 5 different arrays (instead of 5 different
> statements)
> 
> I have tried the following codes, however the last statement (paste("T",
> substring(i,3,4), sep="") <- c(bb ......) gives error message reading "Error
> in paste("T", substring(i, 3, 4), sep = "") <- c(bb = paste(paste("T",
> : target of assignment expands to non-language object"
> 
> for (i in unique(a$id))
>   for (j in unique(a$pro))
>     assign(paste(paste("T", substring(i,3,4), sep=""), j, sep="."),
> sum(subset(a, a$id == i & a$pro == j)$sal))
>     paste("T", substring(i,3,4), sep="") <- c(bb=paste(paste("T",
> substring(i,3,4), sep=""),j, sep="."),ee=paste(paste("T", substring(i,3,4),
> sep=""),j, sep="."),
> 
> gg=paste(paste("T", substring(i,3,4), sep=""),j,
> sep="."),tt=paste(paste("T", substring(i,3,4), sep=""),j, sep="."),
> 
> uu=paste(paste("T",
> substring(i,3,4), sep=""),j, sep="."))
> 
> Your solution to this problem would be highly appreciated.
> 
> 
> 
> Steve
> 
> 	[[alternative HTML version deleted]]
> 
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