Working with objects

You can create an object using the <- operator:

n<-10
n
## [1] 10

In the preceding code, an object called n is created. A value of 10 has been assigned to this object. The assignment can also be made using the assign() function, although this isn't very common.

Once the object has been created, it is possible to perform operations on it, like in any other programming language:

n+5
## [1] 15

These are some examples of basic operations.

Let's create our variables:

x<-4
y<-3

Now, we can carry out some basic operations:

  • Sum of variables:
x + y
## [1] 7
  • Subtraction of variables:
x - y
## [1] 1
  • Multiplication of variables:
x * y
## [1] 12
  • Division of variables:
x / y
## [1] 1.333333
  • Power of variables:
x ** y
## [1] 64

Likewise in R, there are defined constants that are widely used, such as the following ones:

  • The pi () number :
x * pi
## [1] 12.56637
  • Exponential function:
exp(y)
## [1] 20.08554

There are also functions for working with numbers, such as the following:

  • Sign (positive or negative of a number):
sign(y)
## [1] 1
  • Finding the maximum value:
max(x,y)
## [1] 4
  • Finding the minimum value:
min(x,y)
## [1] 3
  • Factorial of a number:
factorial(y)
## [1] 6
  • Square root function:
sqrt(y)
## [1] 1.732051

It is also possible to assign the result of previous operations to another object. For example, the sum of variables x and y is assigned to an object named z:

z <- x + y
z
## [1] 7

As shown previously, these functions apply if the variables are numbers, but there are also other operators to work with strings:

x > y
## [1] TRUE
x + y != 8
## [1] TRUE

The main logical operators are summarized in the following table:

Operator Description
< Less than
<= Less than or equal to
> Greater than
>=  Greater than or equal to
== Equal to
!= Not equal to
!x Not x
x y
x & y x and y
isTRUE(x) Test if x is TRUE

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