Data types in R

Before we get into data structure concepts, let's look into data types provided by the R programming language. A basic data structure with a homogenous data type is based on a contiguous sequence of cells to enable fast access to any particular dataset. All homogeneous types support a single data type.

For example, in Figure 3.1 we have a numeric, logical, and character data type, however, it is stored as character.

Figure 3.1: Example of vector stored as character

Similarly, a matrix with multiple data types, as shown in Figure 3.2, will be coerced and stored as character data type. The array is an extension of the matrix from 2-D to n-D.

Figure 3.2: A matrix with numeric and characters are stored as 2D matrix with characters data type

All elements of a homogeneous data structure must be the same type, so R attempts to combine the different data types to the most flexible type in a priority order as shown in Figure 3.3:

Figure 3.3: Priority order of data types during coercion...