An atomic vector that has two additional attributes: a number of rows and a number of columns.
- Data Frame
A two-dimensional data structure in R in which the columns are atomic vectors that can be of different types.
- Case (also called an Individual)
An individual unit under study. In a data frame in R, the rows correspond to cases.
- Variable (in Data Analysis)
In data analysis, a variable is a measurement made on the individuals in a study.
- Categorical Variable (in Data Analysis)
In data analysis, a categorical variable is a variable whose values cannot be expressed meaningfully by numbers.