CODEWITHSUNDEEP
rlistsapply
Mike.Gahan
Mike.Gahan

Reputation: 4615

Comparing Each Element of Two Lists in R

I have a dataset in R with the following structure:

data <- structure(list(Cust_ID = c("003", "023", "023", "023", "023", 
"041", "056", "056"), Record_Date = list(structure(16130, class = "Date"), 
    structure(c(16130, 16130, 16130, 16130), class = "Date"), 
    structure(c(16150, 16150, 16150, 16150), class = "Date"), 
    structure(c(16161, 16161, 16161, 16161), class = "Date"), 
    structure(c(16162, 16162, 16162, 16162), class = "Date"), 
    structure(16133, class = "Date"), structure(c(16088, 16088
    ), class = "Date"), structure(c(16095, 16095), class = "Date")), 
    Compare_Date = list(structure(16130, class = "Date"), structure(c(16130, 
    16150, 16161, 16162), class = "Date"), structure(c(16130, 
    16150, 16161, 16162), class = "Date"), structure(c(16130, 
    16150, 16161, 16162), class = "Date"), structure(c(16130, 
    16150, 16161, 16162), class = "Date"), structure(16133, class = "Date"), 
        structure(c(16088, 16095), class = "Date"), structure(c(16088, 
        16095), class = "Date"))), row.names = c(NA, -8L), class = "data.frame", .Names = c("Cust_ID", 
"Record_Date", "Compare_Date"))

  Cust_ID                Record_Date               Compare_Date
1     003                      16130                      16130
2     023 16130, 16130, 16130, 16130 16130, 16150, 16161, 16162
3     023 16150, 16150, 16150, 16150 16130, 16150, 16161, 16162
4     023 16161, 16161, 16161, 16161 16130, 16150, 16161, 16162
5     023 16162, 16162, 16162, 16162 16130, 16150, 16161, 16162
6     041                      16133                      16133
7     056               16088, 16088               16088, 16095
8     056               16095, 16095               16088, 16095

I would like to compare each element of "Record_Date" and each element of "Compare_Date." I want the result to be equal to the amount of times the "Compare_Date" is within 14 days after the "Record_Date." I know how to compare two vectors, but comparing two lists seems to be giving me trouble. I have tried using lapply or sapply, but those can only loop through one list at a time.

Does anyone have an easy solution to this problem? I would expect the expected output to look like the following:

   Within14
1:        0
2:        2
3:        1
4:        0
5:        1
6:        0
7:        0
8:        0

Upvotes: 1

Views: 2316

Answers (1)

CHP
CHP

Reputation: 17189

Perhaps, you are looking for mapply. You can edit the FUN argument of mapply to do what you want on each RD and CD argument.

mapply passes one element each of data$Record_Date and data$Compare_Date into RD and CD arguments of FUN respectively.

mapply(FUN = function(RD, CD) {
    d <- as.numeric(CD - RD)
    sum(d > 0 & d < 15)
}, RD = data$Record_Date, CD = data$Compare_Date)
## [1] 0 0 2 1 0 0 1 0

Upvotes: 3

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