CODEWITHSUNDEEP
rnaming-conventionsstataabbreviation
nikUoM
nikUoM

Reputation: 669

How to address several objects named in the same structure in R?

I'd like to know how to include every object that fulfils certain naming requirements in my arguments in R. Let's say the objects are all called something like this

var01 var02 var03 var04 varnn

What I would do in Stata for instance would be simply this

tab1 var*

and it would tabulate every variable with the first 3 letters "var".

In an earlier version of this post I was quite vague about what I actually want to do in my R project. So here goes. I've got a for loop, that iterates over 650 instances, with the goal of appending 6 datasets for every one of these instances. However, for some (I don't know which), not all 6 datasets exist, which is why the rbind command that's written like this fails: 

rbind(data01, data02, data03, data04, data05, data06)

I'd therefore like to run something like this

rbind(data*)

So as to account for missing datasets. Sorry for the confusion, I wasn't being clear enough when I originally wrote the question.

Just for reference, here is the whole loop:

for(i in 1:650){
  try(part1 <-  read.csv(file = paste0("Twitter Scrapes/searchTwitter/09July/",MP.ID[i],".csv")))
  try(part2 <-  read.csv(file = paste0("Twitter Scrapes/userTimeline/08July/",MP.ID[i],".csv")))
  try(part3 <-  read.csv(file = paste0("Twitter Scrapes/userTimeline/16July/",MP.ID[i],".csv")))
  try(part4 <-  read.csv(file = paste0("Twitter Scrapes/searchTwitter/17July/",MP.ID[i],".csv")))
  try(part5 <-  read.csv(file = paste0("Twitter Scrapes/userTimeline/24July/",MP.ID[i],".csv")))
  try(part6 <-  read.csv(file = paste0("Twitter Scrapes/searchTwitter/24July/",MP.ID[i],".csv")))
  allParts <- ls(pattern = "^part*")
  allNames <- paste(allParts, collapse = ", ") # this is just what I tried just now, didn't work though
  combined.df <- rbind(ALL THE DATASETS WITH PART)) 
}

Upvotes: 1

Views: 81

Answers (1)

thothal
thothal

Reputation: 20329

Data

var01 <- sample(2, 10, TRUE)
var02 <- sample(2, 10, TRUE)
var03 <- sample(2, 10, TRUE)
vvv01 <- sample(2, 10, TRUE) # variable which should not be tabulated

Code

allV <- ls(pattern = "^var.*") # vector of all variables starting with 'var'
lapply(allV, function(.) table(get(.)))

Explanation

With ls you get all variables which are named according to the pattern you provide. Then, you loop over all these variables, retrieve the variable by its name and tabulate it.

Update

With your recent changes what I would do is the following:

allV <- lapply(ls(pattern = "^part.*"), get) #stores all part variables in a list
combined.df <- do.call(rbind, allV) # rbinds all of them

Upvotes: 3

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