Comparison of values in a columns in a data frame inside a list

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I have a list of data frames each containing 3 columns,

df.1 <- data.frame(data=cbind(rnorm(5, 0), rnorm(5, 2), rnorm(5, 5)))
df.2 <- data.frame(data=cbind(rnorm(5, 0), rnorm(5, 2), rnorm(5, 5)))

names(df.1) <- c("a", "b", "c")
names(df.2) <- c("a", "b", "c")

ls.1<- list(df.1,df.2)
names(ls.1) <- c("cat", "dog")
ls.1

Now I also have another list containing 3 columns.

df.1 <- data.frame(data=cbind(rnorm(5, 0), rnorm(5, 2), rnorm(5, 5)))
df.2 <- data.frame(data=cbind(rnorm(5, 0), rnorm(5, 2), rnorm(5, 5)))

names(df.1) <- c("a", "b", "c")
names(df.2) <- c("a", "b", "c")

ls.2<- list(df.1,df.2)
names(ls.2) <- c("cow", "pig")
ls.2

I want to compare column b of cat with column b of cow*, and if the entire value of columns are equal say TRUE else FALSE for the column and then move on to compare column b of dog with column b of pig*. The value return will be a single TRUE if all the values of the compared columns are same or a single FALSE. If I have 5 dataframe in a list I should have 5 TRUE or FALSE.

I tried this, but it did not work.

chcfunc <- function(a,b){(ifelse(a[[,2]]==b[[,2]],FALSE,TRUE))}
chc <- lapply(ls.1,ls.2,chcfunc)
dataframe r list
1 Answers

If we want to compare the 'b' columns in corresponding list elements, use Map from base R

Map(function(x, y) all(x$b == y$b, na.rm = TRUE), ls.1, ls.2)

Or use setequal

Map(setequal, ls.1, ls.2)

Or with map2 from purrr

library(purrr)
map2(ls.1, ls.2, ~ all(.x$b == .y$b, na.rm = TRUE))
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