Numbers in R are objects that represent numerical values. They can be integers, floating-point numbers, or complex numbers.
- Integers are whole numbers, such as 1, 2, 3, and so on. They are represented in R by the `integer` class.
- Floating-point numbers are numbers that have a decimal point, such as 1.23, 3.14, and so on. They are represented in R by the `numeric` class.
- Complex numbers are numbers that have a real and imaginary part, such as 1 + 2i, 3 - 4i, and so on. They are represented in R by the `complex` class.
In R, numbers are generally treated as numeric objects. This means that even if you see a number like "1" or "2" in R, which you might think of as integers, they are likely represented behind the scenes as numeric objects (so something like "1.00" or "2.00"). This isn't important most of the time, but it can be important in some cases.
For example, if you want to explicitly create an integer object in R, you need to specify the L suffix. So entering 1 in R gives you a numeric object; entering 1L explicitly gives you an integer object.
There are also two special numbers in R: Inf and NaN. Inf represents infinity, and NaN represents a non-number.
- Inf is used to represent entities like 1 / 0. This way, Inf can be used in ordinary calculations; for example, 1 / Inf is 0.
- NaN is used to represent undefined values. For example, 0 / 0 is NaN. NaN can also be thought of as a missing value.
