I can take the sum of the target
column by the levels in the categorical columns which are in catVariables
. However, instead of doing this in a for loop I want to apply this to all categorical columns at once. For loop will make the code run for longer and doing this in a vectorized way will be faster.
# Data
col1 <- c("L", "R", "R", "L", "R", "L", "R", "L")
col2 <- c("R", "R", "R", "L", "L", "R", "L", "R")
col3 <- c("L", "-", "L", "R", "-", "L", "R", "-")
target <- c(1, 0, 0, 1, 1, 0, 1, 0)
dat <- data.frame("col1" = col1, "col2" = col2, "col3" = col3, "target" = target)
dat[sapply(dat, is.character)] <- lapply(dat[sapply(dat, is.character)], as.factor)
catVariables <- names(Filter(is.factor, dat))
# test
col1 <- c("L", "R", "R", "L", "R", "L", "R", "L")
col2 <- c("R", "R", "R", "L", "L", "R", "L", "R")
col3 <- c("L", "-", "L", "R", "-", "L", "R", "-")
target <- c(1, 0, 0, 1, 1, 0, 1, 0)
test_dat <- data.frame("col1" = col1, "col2" = col2, "col3" = col3, "target" = target)
for (col in catVariables){
ratios <- rowsum(dat[["target"]], dat[[col]])/sum(dat[["target"]])
print(ratios)
dat[[col]] <- ratios[match(dat[[col]],names(ratios[,1]))]
test_dat[[col]] <- ratios[match(test_dat[[col]], names(ratios[,1]))]
}
CodePudding user response:
We may use across
in dplyr
for doing the rowsum
on multiple columns
library(dplyr)
dat %>%
mutate(across(all_of(catVariables),
~ {tmp <- rowsum(target, .x)/sum(target);
tmp[match(.x, row.names(tmp))]}))
-output
col1 col2 col3 target
1 0.5 0.25 0.25 1
2 0.5 0.25 0.25 0
3 0.5 0.25 0.25 0
4 0.5 0.75 0.50 1
5 0.5 0.75 0.25 1
6 0.5 0.25 0.25 0
7 0.5 0.75 0.50 1
8 0.5 0.25 0.25 0
Or with test_dat
/train data ('dat'), an option is to loop over the test_dat
, extract the corresponding column from 'dat' using column name (cur_column()
) to calculate the rowsum
by group, and then match
the 'test_dat' column values with the row names of the output to expand the data
test_dat %>%
mutate(across(all_of(catVariables),
~ {tmp <- rowsum(dat[["target"]], dat[[cur_column()]])/sum(dat[["target"]]);
tmp[match(.x, row.names(tmp))]}))
col1 col2 col3 target
1 0.5 0.25 0.25 1
2 0.5 0.25 0.25 0
3 0.5 0.25 0.25 0
4 0.5 0.75 0.50 1
5 0.5 0.75 0.25 1
6 0.5 0.25 0.25 0
7 0.5 0.75 0.50 1
8 0.5 0.25 0.25 0