Trying to repeat the same code for multiple dataframes - r

Question

I have the follwing code that takes a dataframe called dft1 and then produces a resulting dataframe called dfb1. I want to repeat the same code for multiple input dataframes such as dft1, dft2 all indexed by a number towards the end and then store the results using the same pattern i.e. dfb1, dfb2, ....
I have tried many methods such as using dapply or for loops but given the nature of the code inside I wasn't able to get the intended results.
#define the function for rolling
window <- 24
rolling_lm <-
rollify(.f = function(R_excess, MKT_RF, SMB, HML) {
lm(R_excess ~ MKT_RF + SMB + HML)
}, window = window, unlist = FALSE)
#rolling over the variable
dfb1 <-
dft1 %>%
mutate(rolling_ff =
rolling_lm(R_excess,
MKT_RF,
SMB,
HML)) %>%
mutate(tidied = map(rolling_ff,
tidy,
conf.int = T)) %>%
unnest(tidied) %>%
slice(-1:-23) %>%
select(date, term, estimate, conf.low, conf.high) %>%
filter(term != "(Intercept)") %>%
rename(beta = estimate, factor = term) %>%
group_by(factor)

Answer 1

Add the command you want to apply to each dataframe in a function
apply_fun <- function(df) {
df %>%
mutate(rolling_ff =
rolling_lm(R_excess,
MKT_RF,
SMB,
HML)) %>%
mutate(tidied = map(rolling_ff,
tidy,
conf.int = T)) %>%
unnest(tidied) %>%
slice(-1:-23) %>%
select(date, term, estimate, conf.low, conf.high) %>%
filter(term != "(Intercept)") %>%
rename(beta = estimate, factor = term) %>%
group_by(factor)
}
Now apply the function to each dataframe and store the results in a list
n <- 10
out <- setNames(lapply(mget(paste0("dft", 1:n)), apply_fun), paste0("dfb", 1:n))
Assuming you have input dataframes like dft1, dft2...this will output a list of dataframes which you can now access doing out[['dfb1']], out[['dfb2']] and so on. Change the value of n based on number of dft dataframes you have.
If the data is already present in a list we can avoid mget by doing
setNames(lapply(result, apply_fun), paste0("dfb", 1:n))