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| Objects in R |
Objects
R allows the user to save the data by storing it inside an object.
What’s an object?
An object is a name that you can use to call up stored data. For example, you can save data into an object like a or b.
> a <- 5
> a
[1] 5
There are many types of objects in R. Two of the most common are as lists and functions. Example of a list:
> a <- list(1, "Hello, world!", FALSE)
Lists can contain mixed types of data (number, string and boolean in this example).
There are many built in functions in R. The user can also make a 'user defined' function, as you see below. The following creates the function circleArea that calculates the area of a circle (A = π r2).
>circleArea <- function(r){
A <- pi * r^2
return(A)
}
How to create an Object in R?
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To create an R object, choose a name and then use the less-than symbol,
<, followed by a minus sign,-, to save data into it. This combination looks like an arrow,<-. R will make an object, give it your name, and store in it whatever follows the arrow. You can also use the '=' sign, but this is a less common method to assign a value to an object and generally frowned upon. -
When the user calls the object in the console it provides the output on the next line. For example:
> die <- 1:6
> die
[1] 1 2 3 4 5 6
-
You can name an object in R almost anything you want, but there are a few rules. First, a name cannot start with a number. Second, a name cannot use some special symbols, like
^, !, $, @, +, -, /, or *: -
R also understands capitalization (or is case-sensitive), so name and Name will refer to different objects.
-
You can see which object names you have already used with the function
ls().