CODEWITHSUNDEEP
rlistif-statementdataframe
Brett
Brett

Reputation: 27

How do you create a new column inside a list of data frames according to values inside each specific data frame?

I have a large set of data for which I have a list of data frames based on names of stations and I wish to create a new column with numerical values based on a rows checkout name and return name. A sample of the data is shown below:

fz$'66th & Center'
Bike CheckoutKioskName ReturnKioskName
24583  191     66th & Center   66th & Center
24584  191     66th & Center   66th & Center
24585  191     66th & Center   66th & Center
24586  191     66th & Center   66th & Center
24587  191     66th & Center   66th & Center
24588  191     66th & Center   66th & Center
24589   11     66th & Center   66th & Center
24590   11     66th & Center   66th & Center
24591   11     66th & Center   66th & Center
24592   11     66th & Center   66th & Center'

I want to create a new column named 'count' based on if the CheckoutKioskName is the same as ReturnKioskName then the count value should be 0, if the CheckoutKioskName isn't the same as the list value name ('66th & Center' in this case) then the count value should be -1, and the last option is if the ReturnKioskName isn't the same as the list value name then the count value should be 1. My attempt at doing this is below in the if else statements. I keep getting errors when using it either when the columns are factors or when the columns are characters. 

if(test$CheckoutKioskName == test$ReturnKioskName){
  test$count <- 0
}else{
  if(test$ReturnKioskName != t){
    test$count <- -1
  }else{
    if(test$CheckoutKioskName != t){
      test$count <- 1
    }
  }
}

I want to think there is a way to use lapply to complete this task but I continue to fail whenever I use it here.

I appreciate any help I can get.

Upvotes: 1

Views: 51

Answers (2)

akrun
akrun

Reputation: 887118

We can use lapply

lapply(names(fz), function(nm) {fz1 <- fz[[nm]]
    transform(fz1, Count = ifelse(CheckoutKioskName == ReturnKioskName, 0,
                ifelse(CheckoutKioskName ! = rep(nm, nrow(fz1)), -1, 1)))})

Upvotes: 1

e-cology
e-cology

Reputation: 11

Try going via which statements and store your flags in your new column. I recommend converting the tested columns to character, but then couldn't try if that makes a difference, because I don't have time to recreate your data ;)

test$count[which(test$CheckoutKioskName == test$ReturnKioskName)] <- 0

...and so on. Should do the trick.

Upvotes: 0

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