How to apply a condition to all columns of a data frame specified in a vector in R

Question

I want to apply a condition to different columns (specified in a vector) of a data frame.

For example if I have

trial_m <- as.data.frame(cbind(c(0,1,1), c(0, 1, 0), c(0, 1, 1), c(0, 1, 0)))
aux_v <- c("V1","V2","V3")

I would like to know where in trial_m all of the values are 1 for each of the rows.

I know I can do this:

trial_m[, aux_v[1]] == 1 & trial_m[, aux_v[2]] ==  1 & trial_m[, aux_v[3]] ==  1

But aux_v can have a different lengths, for example aux_v = c("V1") . How can I apply a condition to all columns specified in the aux_v vector without typing all the conditions as above (the condition will be the same for all of the elements of the vector, to be equal 1)?

Answer 1

We can use if_all

library(dplyr)
trial_m %>%
   filter(if_all(all_of(aux_v), ~ .x == 1))

-output

   V1 V2 V3 V4
1  1  1  1  1

Answer 2

Maybe with data.table in two steps.

library(data.table)

setDT(trial_m)

temp <- trial_m[, lapply(.SD, function(x) x == 1), .SDcols = aux_v]
temp <- rowSums(temp) == nrow(temp)

temp
[1] FALSE  TRUE FALSE

Answer 3

I'm not sure what your expected output would be, but to check the conditions in your sample (all values for a row == 1 across variable number of columns), you could try:

trial_m <- as.data.frame(cbind(c(0,1,1), c(0, 1, 0), c(0, 1, 1), c(0, 1, 0)))
aux_v <- c("V1","V2","V3")

apply(trial_m[aux_v], 1, function(x) all(x == 1))
#[1] FALSE  TRUE FALSE

# change to only one column
aux_v <- c("V1")
apply(trial_m[aux_v], 1, function(x) all(x == 1))
#[1] FALSE  TRUE  TRUE

If you wanted to create a column that would be included in the dataset, and name the column the variables included:

# cols 1 and 3
aux_v <- c("V1","V3")

trial_m[,paste0(paste(aux_v, collapse = "_"), "_check")] <- apply(trial_m[aux_v],1, function(x) all(x == 1))

#  V1 V2 V3 V4 V1_V3_check
#1  0  0  0  0       FALSE
#2  1  1  1  1        TRUE
#3  1  0  1  0        TRUE