Linked Questions
11 questions linked to/from How to check if object (variable) is defined in R?
7
votes
1
answer
3k
views
Verify object existence inside a function in R [duplicate]
I want to determine whether an object exists inside a function in R:
foo <- function() {
y <- "hello"
if (exists(y, envir = sys.frame())) print(y)
}
foo()
Error in exists(y, envir = sys....
- 2,919
0
votes
0
answers
73
views
Test to see if object exists in R [duplicate]
Is there an easy way to see if an object exists in R? I would love a function that returns TRUE if the object has been defined and FALSE if the object has not been defined. Thus far, everything I try ...
- 265
129
votes
7
answers
83k
views
Filter for complete cases in data.frame using dplyr (case-wise deletion)
Is it possible to filter a data.frame for complete cases using dplyr? complete.cases with a list of all variables works, of course. But that is a) verbose when there are a lot of variables and b) ...
- 4,145
135
votes
7
answers
137k
views
How to test if list element exists?
Problem
I would like to test if an element of a list exists, here is an example
foo <- list(a=1)
exists('foo')
TRUE #foo does exist
exists('foo$a')
FALSE #suggests that foo$a does not exist
...
- 31.7k
24
votes
1
answer
26k
views
R : Check if R object exists before creating it
I am trying to skip steps loading data from large files if this has already been done earlier. Since the data ends up in (for example) mydf, I thought I could do:
if( !exists(mydf) )
{
#... steps ...
- 1,274
9
votes
2
answers
1k
views
List of packages that need an update
How can I produce a list of packages that need an update, i.e. a table with package name, version currently installed and version available at the repository?
I have tried to hack packageStatus(), ...
- 59.4k
-1
votes
2
answers
9k
views
R - check if a variable exists
I thought I had figured this one out. I have a variable called:
count_1
It's just a vector with one element. As I go through my loops, sometimes it has a value, and at other times it doesn't. All I ...
- 369
1
vote
2
answers
496
views
How to check if any variable is defined in argument (...) in R?
If I have a function with argument (...) and want to check if a variable is defined in the argument. How can I do this? I have already looked at the solution provided at this link: How to check if ...
- 175
1
vote
1
answer
1k
views
If value exists in environment
Is there a way how to check if value exists in R environment and if == TRUE, assign this existing value otherwise assign something else?
In other words, I have nothing in my R right now and I created ...
user4394417
0
votes
2
answers
404
views
How to check if an executable command exists in R
Is there a way in R to check if a command exists in the operating system?
I know that file.exists(file) can be used to check if a file exists. But what about a command on the system PATH?
(This is ...
- 22.4k
-2
votes
1
answer
170
views
detect numeric values in a string
I have to create a function which will detect if there is any non numeric value present in input. For this I have written this code
test<-function(x){
if(is.numeric(x)){
return(T)
}else{
...
- 1,944