[R] Avoid for-loop in creating data.frames

[Andreas Wittmann]

Hi babtiste,

thank you very much for your fast answer. your solution is very good, 
but i also need the dimnames as in the for-loop for further calculations.

best regards

Andreas




baptiste auguie wrote:
> Hi,
>
> Is the following close enough?
>
> apply(set2, 2, function(x) x[is.na(x)])
>
> HTH,
>
> baptiste
>
> 2009/12/10 Andreas Wittmann <andreas_wittmann at gmx.de>:
>   
>> Dear R-users,
>>
>> after several tries with lapply and searching the mailing list, i want to
>> ask, wheter and how it is possibly to avoid the for-loop in the following
>> piece of code?
>>
>> set2<-as.data.frame(matrix(rnorm(9),ncol=3))
>>
>> set2[1,1] <- NA
>> set2[3,2] <- NA
>> set2[2,1] <- NA
>>
>> dimnames(set2)[1] <- list(c("A","B","C"))
>>
>> r <- !is.na(set2)
>> imp <- vector("list", ncol(set2))
>>
>> for (j in 1:dim(set2)[2])
>> {
>>  imp[[j]] <- as.data.frame(matrix(NA, nrow = sum(!r[,j]), ncol = 1))
>>  dimnames(imp[[j]]) <- list(row.names(set2)[r[,j] == FALSE], 1)
>> }
>>
>>
>> many thanks and best regards
>>
>> Andreas
>>
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>>
>>     
>
>