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VOOZH | about |
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VOOZH | about |
A list in R programming is a generic object consisting of an ordered collection of objects. Lists are one-dimensional, heterogeneous data structures. The list can be a list of vectors, a list of matrices, a list of characters, a list of functions, and so on. A list in R is created with the use of the list() function.
R allows accessing elements of an R list with the use of the index value. In R, the indexing of a list starts with 1 instead of 0.
To create a List in R you need to use the function called "list()". We want to build a list of employees with the details. So for this, we want attributes such as ID, employee name, and the number of employees.
Example:
[[1]] [1] 1 2 3 4 [[2]] [1] "Debi" "Sandeep" "Subham" "Shiba" [[3]] [1] 4
Naming list components make it easier to access them.
Example:
$name [1] "Sudheer" $age [1] 25 $city [1] "Delhi"
We can access components of an R list in two ways.
All the components of a list can be named and we can use those names to access the components of the R list using the dollar command.
Example:
$ID [1] 1 2 3 4 $Names [1] "Debi" "Sandeep" "Subham" "Shiba" $`Total Staff` [1] 4 Accessing name components using $ command [1] "Debi" "Sandeep" "Subham" "Shiba"
We can also access the components of the R list using indices. To access the top-level components of a R list we have to use a double slicing operator "[[ ]]" which is two square brackets and if we want to access the lower or inner-level components of a R list we have to use another square bracket "[ ]" along with the double slicing operator "[[ ]]".
Example:
$ID [1] 1 2 3 4 $Names [1] "Debi" "Sandeep" "Subham" "Shiba" $`Total Staff` [1] 4 Accessing name components using indices [1] "Debi" "Sandeep" "Subham" "Shiba" Accessing Sandeep from na...
A R list can also be modified by accessing the components and replacing them with the ones which you want.
Example:
Before modifying the list $ID [1] 1 2 3 4 $Names [1] "Debi" "Sandeep" "Subham" "Shiba" $`Total Staff` [1] 4 After modified the list $ID [1] 1 2 3 4 5 $Names [1] "Debi" "Sandeep" "Subham" ...
Two R lists can be concatenated using the concatenation function. So, when we want to concatenate two lists we have to use the concatenation operator.
Syntax
list = c(list, list1)
list = the original list
list1 = the new list
Example:
Before concatenation of the new list $ID [1] 1 2 3 4 $Names [1] "Debi" "Sandeep" "Subham" "Shiba" $`Total Staff` [1] 4 After concatenation of the new list [1] "Debi" "Sandeep" "Subham" "S...
To add an item to the end of list, we can use append() function.
[1] 1 5 6 3 45 [1] 1 5 6 3
To delete components of a R list, first of all, we need to access those components and then insert a negative sign before those components. It indicates that we had to delete that component.
Example:
Before deletion the list is $ID [1] 1 2 3 4 $Names [1] "Debi" "Sandeep" "Subham" "Shiba" $`Total Staff` [1] 4 After Deleting Total staff components $ID [1] 1 2 3 4 $Names [1] "Debi" "Sand...
We can merge the R list by placing all the lists into a single list.
Output:
[[1]]
[1] 1
[[2]]
[1] 2
[[3]]
[1] 3
[[4]]
[1] "Sun"
[[5]]
[1] "Mon"
[[6]]
[1] "Tue"
Here we are going to convert the R list to vector, for this we will create a list first and then unlist the list into the vector.
[[1]] [1] 1 2 3 4 5 [1] 1 2 3 4 5
We will create matrices using matrix() function in R programming. Another function that will be used is unlist() function to convert the lists into a vector.
The list is: [[1]] [[1]][[1]] [1] 1 [[1]][[2]] [1] 2 [[1]][[3]] [1] 3 [[2]] [[2]][[1]] [1] 4 [[2]][[2]] [1] 5 [[2]][[3]] [1] 6 Class: list After conversion to matrix: [,1] [,2] [,3] [1,...
In this article we have covered Lists in R, we have covered list operations like creating, naming, merging and deleting a list in R language.
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