Hello,
I have a list (mode and class are list) in R that is many elements long and of the form:
length(list)
[1] 5778
list[1:4]
$ID1
[1] "num1"
$ID2
[1] "num2" "num3"
$ID3
[1] "num4"
$ID4
[1] NA
I'd like to convert the $ID2 value to be in one element rather than in two.?? It shows up as c(\"num2\", \"num3\") if I try to use paste(list[2], collapse=""). I need to do this over the length of the entire list, however list2 <- apply(list, 1, paste, collapse="") tells me 'Error in apply : dim(X) must have a positive length'. dim(list) does not have a positive length, which I think is due to the fact that it's a list and not a matrix or data frame.
What I want to get is:
LD> I have a list (mode and class are list) in R that is many elements long and of the form:
>> length(list)
LD> [1] 5778
>> list[1:4]
LD> $ID1
LD> [1] "num1"
LD> $ID2
LD> [1] "num2" "num3"
LD> $ID3
LD> [1] "num4"
LD> $ID4
LD> [1] NA
LD> I'd like to convert the $ID2 value to be in one element rather
LD> than in two.?? It shows up as c(\"num2\", \"num3\") if I try to
LD> use paste(list[2], collapse="").
You want list[[2]], not list[2]:
[1] "num2 num3"
LD> I need to do this over the length of the entire list, however
LD> list2 <- apply(list, 1, paste, collapse="") tells me 'Error in
LD> apply : dim(X) must have a positive length'.
You want to use `lapply' not `apply':
tt1 <- lapply(tt, paste, collapse=" ")
tt1
$ID1
[1] "num1"
$ID2
[1] "num2 num3"
$ID3
[1] "num4"
$ID4
[1] "NA"
LD> What I want to get is:
>> list[1:4]
LD> $ID1
LD> [1] "num1"
LD> $ID2
LD> [1] "num2 num3"
LD> $ID3
LD> [1] "num4"
LD> $ID4
LD> [1] NA
In that case, if you don't want NA's to turn into strings:
$ID1
[1] "num1"
$ID2
[1] "num2 num3"
$ID3
[1] "num4"
$ID4
[1] NA
HTH.
Cheers,
Berwin
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