One of the object oriented systems in the R language.
S3 is the main object oriented system in R.
Read more about it here
Base R uses S3.
The other two common object oriented systems are S4 and R5.
Questions tagged [r-s3]
149 questions
2
votes
1 answer
How to export new generic function for new S3 class?
I define a new function work_with_myS3 that is supposed to work with my new S3 class myS3:
work_with_myS3 = function (x) {
UseMethod("work_with_myS3", x)
}
work_with_myS3.myS3 = function(x) {
some code
}
When I source this in my normal R…
jakub
- 4,774
- 4
- 29
- 46
2
votes
1 answer
Assigning S3 subset operator
I am writing a library to work with an S3 class called "Data" and I need to assign the subset operator, [.Data
In the relevant R file, I have:
`[.Data` <- function(x, condition) {
## body of function
}
There is no problem installing the library,…
Jon Claus
- 2,862
- 4
- 22
- 33
2
votes
1 answer
Subclass of integer64 staying after logical operation (R)
When I subclass the integer64 object from bit64 and then perform a equality test, the result contains logical data, but is still classed with my class rather than being logical. This doesn't happen with integer for example.
Sample…
Corvus
- 7,548
- 9
- 42
- 68
1
vote
2 answers
How to set the additional arguments of a new generic to be the same as their default values in the default method
When implementing a generic method for a new class:
scale.newclass <- function(x, center = TRUE, scale = TRUE) {
...
}
How to guarantee that the default values for additional arguments center and scale always stay consistent with their default…
Karolis Koncevičius
- 9,417
- 9
- 56
- 89
1
vote
2 answers
How can I pass variables between ggplot personal functions?
I am trying to create some functions based on ggplot to create custom plots. The creation of functions is very easy and straight forward, but I cannot figure out the way to share information between the functions to help in the plot creation.
Here…
teoten
- 31
- 1
- 6
1
vote
1 answer
Define S3 Group generics for incompatible classes
Say, I am implementing a custom S3 class, called "myclass":
myvec <- 1:5
class(myvec) <- "myclass"
I define Group Ops generics so that the class is preserved after standard operations.
Ops.myclass <- function(e1, e2) {
if(is(e1, "myclass")) {
…
Karolis Koncevičius
- 9,417
- 9
- 56
- 89
1
vote
0 answers
Using S3 object to analyse other data.frames - noob level question
This was an attempt to understand OOP - taking a tutorial in it now. I'm very new at R and I would consider deleting the question as it is not well formulated. I would not use it for learning or guidance
Part 1 - I want to build a class in S3 using…
iKcon
- 71
- 7
1
vote
0 answers
When I know the class of an R object, can I call the appropriate method directly?
Consider a simple R function:
#' @importFrom BarPackage Bar
Foo <- function (n, x) {
replicate(1e6, Bar(numeric(n), x))
}
If Bar() is a method, then calling Bar.numeric(numeric(n), x) saves R from having to look up the class of numeric(n); in a…
Martin Smith
- 3,687
- 1
- 24
- 51
1
vote
0 answers
R S3 generic methods set to visible FALSE
I have an R object lf which is an element of the class tbl_lazy:
library(dbplyr)
lf <- lazy_frame(a = TRUE, b = 1, c = 2, d = "z", con = simulate_hana())
>class(lf)
[1] "tbl_HDB" "tbl_lazy" "tbl"
With the help of the sloop package, I can see that…
jamoreiras
- 315
- 1
- 14
1
vote
1 answer
Get internal R functions to use my S4 method
I've created a custom S4 class, and the idea is that it represents a vector that's always sorted, so I don't want sort() to actually do anything to it. So I defined a stub version of sort() for my class:
MyClass <- methods::setClass("MyClass",…
Migwell
- 18,631
- 21
- 91
- 160
1
vote
2 answers
$ is an internal generic function, so how did the tibble package extend it?
Because it is on the list of Internal Generic Functions, I know that $ is an internal generic function. To my knowledge, this means that it cannot be extended using S3. Despite this, it is well-known that $ behaves differently for tibbles as it does…
J. Mini
- 1,868
- 1
- 9
- 38
1
vote
1 answer
Does the documentation for rep tell us that it is an internal generic function?
Because it is on the list of Internal Generic Functions, I know that rep is an internal generic function. Could this fact have been derived by only reading the documentation for rep? I have located the following two relevant-looking sections:
rep…
J. Mini
- 1,868
- 1
- 9
- 38
1
vote
1 answer
How do fractions vectors (from MASS) have error checking?
Take the following code that generates a fractions vector:
> example<-MASS:: as.fractions(c(0.2,0.4))
> example
[1] 1/5 2/5
If we were to replace one of these fractions with a string, we get the following error:
> example[1]<-"0/1"
Error in…
J. Mini
- 1,868
- 1
- 9
- 38
1
vote
2 answers
Custom classes for each element in a dataframe in R
I am very new to S3 and was wondering if it was possible given the following data frame:
test <- tibble(
elements = c("one", "two", "three"),
S3 = c("foo", "bar", "foo")
)
I could give each element in the elements column a custom class from the…
MayaGans
- 1,815
- 9
- 30
1
vote
1 answer
Create an S4 class inheriting from a data frame
I am writing an R package. Within this package, I wish to have a special type of a data frame that some of the functions can recognize, with some extra attributes, say, but otherwise behaving exactly like a data frame. One way to achieve what I want…
January
- 16,320
- 6
- 52
- 74