I want to remove certain vectors from a list. I have for example this:
a<-c(1,2,5) b<-c(1,1,1) c<-c(1,2,3,4) d<-c(1,2,3,4,5) exampleList<-list(a,b,c,d) exampleList returns of course: [[1]] [1] 1 2 5 [[2]] [1] 1 1 1 [[3]] [1] 1 2 3 4 [[4]] [1] 1 2 3 4 5 Is there a way to remove certain vectors from a list in R. I want to remove all vectors in the list exampleList which contain both 1 and 5(so not only vectors which contain 1 or 5, but both). Thanks in advance!
Use Filter:
filteredList <- Filter(function(v) !(1 %in% v & 5 %in% v), exampleList) print(filteredList) #> [[1]] #> [1] 1 1 1 #> #> [[2]] #> [1] 1 2 3 4 Filter uses a functional style. The first argument you pass is a function that returns TRUE for an element you want to keep in the list, and FALSE for an element you want to remove from the list. The second argument is just the list itself.
Filter(function(x) length(setdiff(c(1,5), x)) > 0, exampleList).We can use sapply on every list element and remove those elements where both the values 1 and 5 are present.
exampleList[!sapply(exampleList, function(x) any(x == 1) & any(x == 5))] #[[1]] #[1] 1 1 1 #[[2]] #[1] 1 2 3 4 
exampleList[!sapply(exampleList, function(x) all(c(1,5) %in% x) )]
x %in% c(1, 5) which was definitely giving me incorrect results.Here a solution with two steps:
exampleList<-list(a=c(1,2,5), b=c(1,1,1), c=c(1,2,3,4), d=c(1,2,3,4,5)) L <- lapply(exampleList, function(x) if (!all(c(1,5) %in% x)) x) L[!sapply(L, is.null)] # $b # [1] 1 1 1 # # $c # [1] 1 2 3 4 Here is a one-step variant without any definition of a new function
exampleList[!apply(sapply(exampleList, '%in%', x=c(1,5)), 2, all)] (... but it has two calls to apply-functions)