CODEWITHSUNDEEP
r
Jakub Jędrusiak
Jakub Jędrusiak

Reputation: 467

Sum with non-existing object in R

I want to make a simple script where I'll sum some variables according to a fixed naming scheme. But the problem is, not all variables will be used every time. But if I try something like this:

result <- sum(variable1, variable2, variable3, na.rm = TRUE)

I get an error saying there's no variable1. Is there a way to sum only the existing variables and ignore the non-existing ones without declaring all possible variables as NA beforehand?

Upvotes: 0

Views: 208

Answers (3)

akrun
akrun

Reputation: 887511

We could do

 Reduce(`+`, mget(ls(pattern = '^variable\\d+$')))
[1] 15

data

variable2 <- 12
variable3 <- 3

Upvotes: 0

Quixotic22
Quixotic22

Reputation: 2924

duplicate of this

Add this before:

sapply(c("variable1", "variable2", "variable3"), function(x) 
  if(!exists(x)) { assign(x, NA, envir=.GlobalEnv) } 
)

Upvotes: 1

Ronak Shah
Ronak Shah

Reputation: 389135

You can get the variables which are available in the global environment and sum them.

#Dummy variables
variable2 <- 12
variable3 <- 3

sum(unlist(mget(ls(pattern = 'variable\\d+'))), na.rm = TRUE)
#[1] 15

Upvotes: 3

Related Questions