What is and what is an anonymous function in R?

Question

• What is an anonymous function? And why can it be called função lambda?

• What is the usefulness of an anonymous function in language R?

• Where it can be applied (for example, it can be applied in Function Operators)?

Answer 1

What is anonymous function in R?

• One anonymous function Anonymous Function (also known as expression lambda) is a definition of a function that is not linked to an identifier. That is, it is a function created and used, but never assigned to a variable. That is, R does not have a special syntax to create a named function: when you create a function, it uses the regular assignment operator to assign a name. If you choose not to name the function, you will receive a anonymous function.

And why it can be called lambda function?

• Lambda expressions are unnamed functions given as constant values. They may appear anywhere that any other constant, but are typically written as a parameter to some other function.

• The word "lambda" or "lambda expressions" usually if refers to anonymous functions. So, in this sense, a lambda is a type function (anonymous function), but not every function is a lambda (ie, appointed functions are not usually called Mixed).

• Therefore, anonymous functions in fine languages are treated as lambda.

What is the usefulness of an anonymous function in the R language?

Simple example of anonymous function in r:

# Sintaxe de função anônima
(function(x) x * 10)(10)

# equivalente (normal)
fun<-function(x) x * 10

fun(10)

• As the above syntax indicates, you are doing everything at once: a statement and call in a line statement. Therefore, despite of not being transparent when reading it, it is self-contained and you use it because it does not want to define any other function in some other current script (or in an external script): you are dealing with a simple calculation when necessary, and you probably do not use it anywhere else in your code, so it’s not worth it remind him.