Learning R for Geospatial Analysis

Evaluating expressions

We now know how to enter code for R to interpret, whether directly entering it into R's command line or sending it to the command line from a code editor. Our next step will be to see how to use the simplest operations: arithmetic and logical operators and functions.

Using arithmetic and logical operators

The standard arithmetic operators in R are as follows:

• +: Addition
• -: Subtraction
• *: Multiplication
• /: Division
• ^: Power

The following examples demonstrate the usage of these operators:

> 5+3
[1] 8
> 4-5
[1] -1
> 1*10
[1] 10
> 1/10
[1] 0.1
> 2^3
[1] 8

Parentheses can be used to construct more elaborate expressions, as follows:

> 2*(3+1)
[1] 8
> 5^(1+1)
[1] 25

It is better to use parentheses even when it is not required to make the ...