Skip to main content

R as a calculator

We'll assume you have started an R prompt - if not go and start one now.

First steps​

Let's try out R by trying a few interactive commands. First, can R add numbers together?

> 5 + 10
[1] 15

It can! It can also subtract them (-), multiply them (*), divide them (/), or exponentiate them (^).

Note

Start by playing around with these arithmetic operations now to make sure you know what they are doing.

For example, what's 55 to the power of 1010? Try

> 5^10

to find out.

R can also manipulate other things, like strings. Let's try a string now:

> "This is a string"
Note

Strings can also be given using single quotes, as in 'This is also a string'.

However, you can't add two strings together - try it:

> "This is a string" + " as well"
Error in "This is a string" + " as well" : 
  non-numeric argument to binary operator

This illustrates that if you get something wrong R will try to tell you what it is. Here it's telling us that the 'binary operator' (which is +) expects 'numeric arguments' (i.e. numbers), as opposed to the strings we gave it.

That doesn't mean you can't concatenate strings - you can. In R, operations on strings use particular functions. The one we want here is paste():

> paste( "This is a string", "as well" )
[1] This is a string as well.
Note

Why 'paste'? Good question. This illustrates one of the worst aspects of R - some of the built-in functions have fairly cryptic names. Later on we'll suggest some useful libraries that make this easier.