How can I check in R using dplyr the values of a vector if they correspond (exist) to a column of a data frame?

Question

Let's say I have a data frame in R that looks like this :

var1	lc
A	london
B	athens
C	amsterdam
D	new york
E	tokyo
F	barcelona
G	rome
H	mexico city
I	cairo

var1 = c("A","B","C","D","E","F","G","H","I")
lc = c("london","athens","amsterdam","new york","tokyo","barcelona","rome","mexico city","cairo")
df = tibble(var1,lc);df

Now I have a vector of interest that contains some values that I have to check.

var2 = c("A","C","E","F","G","H","I","J","K","L","M")

My condition of interest is that if the elements of the column vector var1 exist in the second vector (var2).

Ideally a want to mutate (dplyr phrase) a new column that will contain the output if this logical condition and must look like this.

var1	lc	condition
A	London	TRUE
B	athens	FALSE
C	amsterdam	TRUE
D	new york	FALSE
E	tokyo	TRUE
F	barcelona	TRUE
G	rome	TRUE
H	mexico city	TRUE
I	cairo	TRUE

How can I do it in R using dplyr ? Any help ?

Answer 1

你可以使用 %in%

df %>% mutate(condition = var1 %in% var2)