CODEWITHSUNDEEP
r
Banjo
Banjo

Reputation: 1251

Remove certain values from a list of vectors

I have a vector with some characters:

The structure glimpse(a)

List of 5
 $ : chr [1:2] "Thai" "Restaurants"
 $ : chr [1:2] "Vietnamese" "Restaurants"
 $ : chr [1:3] "Restaurants" "Vegetarian" "Indian"
 $ : chr [1:5] "Nightlife" "Bars" "Restaurants" "Thai" ...
 $ : chr [1:4] "Asian Fusion" "Chinese" "Japanese" "Restaurants"

Here is a dput(a)

list(c("Thai", "Restaurants"), c("Vietnamese", "Restaurants"), 
    c("Restaurants", "Vegetarian", "Indian"), c("Nightlife", 
    "Bars", "Restaurants", "Thai", "Sports Bars"), c("Asian Fusion", 
    "Chinese", "Japanese", "Restaurants"))

I want to drop some values by exclusion. For example, the values below are the only values which should stay in the vector. All other values should be removed, with no replacement. 

c("Chinese", "Japanese", "Sushi Bars", "Indian", "Thai", "Vietnamese", "Korean","Taiwanese", "Malaysian", "Mongolian", "Indonesian", "Laotian", "Myanmar", "Pan Asian", "Tempura", "Wok")

So, I tried the solution from this post: How to delete multiple values from a vector?

So I did:

rm <-  c("Chinese", "Japanese", "Sushi Bars", "Indian", "Thai", "Vietnamese", "Korean","Taiwanese", "Malaysian", "Mongolian", "Indonesian", "Laotian", "Myanmar", "Pan Asian", "Tempura", "Wok")

a [! a %in% rm]

But nothing changes?!. Anny Idea how to remove those values from a that doesn't belong to rm

Upvotes: 0

Views: 1707

Answers (1)

akrun
akrun

Reputation: 886948

We can do a setdiff if the elements are unique by looping over the list elements with lapply

lapply(a,  setdiff, rm)

Or else, use %in% and then negate

lapply(a, function(x) x[!x %in% rm])

Upvotes: 2

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