CODEWITHSUNDEEP
rfunctionloops
Fordo
Fordo

Reputation: 17

R create a loop for a list of data frames

I currently have a list which is made up of around 80+ data frames, what I would like to do is to loop a chunk of code for each individual data frame within the list, without naming each one individually, or splitting them into individual data frames to work on.

Currently I split the list into each individual data frame using the below code:

dat5split <- setNames(split(dat5, dat5$CODE), paste0("df", unique(dat5$CODE)))

list2env(dat5split, globalenv())

I then work through each data frame individually: 

    # call in SPC function and write to 'results10000'

    results10000<-SPC_XBAR(df10000,vol_n,seasonality)

    results10000 = results10000 %>%
      cbind(Spec = df10000$CODE) %>%
      subset(`table_n` == 1)

    results10000 <- results10000[order(results10000$tpd),]

    results10000$Date <- as.Date(cbind(Date = df10000$CENSUS_DATE))

# call in SPC function and write to 'results10001'

    results10001<-SPC_XBAR(df10001,vol_n,seasonality)

    results10001 = results10001 %>%
      cbind(Spec = df10001$CODE) %>%
      subset(`table_n` == 1)

    results10001 <- results10001[order(results10001$tpd),]

    results10001$Date <- as.Date(cbind(Date = df10001$CENSUS_DATE))

Currently I call in the function 'SPC_XBAR' to where vol_n and seasonality are set earlier in the code. The script then passes the values to the function which then assigns the results to 'results10000, results10001' etc etc. Upon which I do a small bit of data wrangling on each newly created data frame before feeding the results back into sql server at the end.

As you can see each one is being individually hard coded which is not efficient.

What I would like to do is to loop a chunk of code for each individual data frame within the list, without naming each one individually.

I believe a loop would solve this issue but I am a little inexperienced when it comes to the ability to create a loop around it. Any advice would be much appreciated.

Cheers

Upvotes: 0

Views: 71

Answers (1)

Marco
Marco

Reputation: 256

Have you considered using lapply instead of a loop throughout the list? Check it here...

EDIT: I try to elaborate a bit more... What happens if you do this:

myFunction <- function(x) {
    results<-SPC_XBAR(x,vol_n,seasonality)

    results = results %>%
      cbind(Spec = x$CODE) %>%
      subset(`table_n` == 1)

    results <- results[order(results$tpd),]

    results$Date <- as.Date(cbind(Date = x$CENSUS_DATE))

    results
}

lapply(dat5split, myFunction)

I would expect it to return a list of the resulting datasets

Upvotes: 1

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