CODEWITHSUNDEEP
r
Yamuna_dhungana
Yamuna_dhungana

Reputation: 663

How to apply function to each group of data frame

I have a dataframe called covars with three ethnicities. How do I apply function Get_STATs so I can get the output for each ethnicity?

Right, now I am running it like this:

tt <- covars[covars$ETHNICITY == "HISPANIC",]
Get_STATs(tt)

tt <- covars[covars$ETHNICITY == "WHITE",]
Get_STATs(tt)

tt <- covars[covars$ETHNICITY == "ASIAN",]
Get_STATs(tt)

I tried to run it like this aggregate(covars, by = list(covars$ETHNICITY), FUN = Get_STATs) which generates error rror: $ operator is invalid for atomic vectors

Upvotes: 0

Views: 193

Answers (2)

Jake Bernards
Jake Bernards

Reputation: 95

Depending on the Get_STATs function, you can use dplyr:

tt <- 
  covars %>% 
  group_by(ETHNICITY) %>% 
  Get_STATs()

Upvotes: 0

akrun
akrun

Reputation: 886938

aggregate runs on each column separately, we may need by

do.call(rbind, by(covars, covars$ETHNICITY, FUN = Get_STATs))

Or split into a list and loop over the list and apply the function

do.call(rbind, lapply(split(covars, covars$ETHNICITY), Get_STATs))

If we need the ETHNICITY names as well

lst1 <- split(covars, covars$ETHNICITY)
do.call(rbind, Map(cbind, ETHNICITY = names(lst1), lapply(lst1, Get_STATs)))

Upvotes: 1

Related Questions