Data Frames
The DataFrame<R, C> class represents a data set that consists of multiple variables that may have different element types. The columns in a data frame are generic vectors. All columns have the same number of observations.
The rows and columns of a data frame can be accessed by position or by key. The collection of row keys or column keys is called an index. A data frame has a row index and a column index. Indexes were discussed in the previous section.
Overview
In this section:
Constructing data frames How to create data frames.
Basic Operations on Data Frames How to load data from and save data to external data sources like data bases, text files and other file formats.
Vectors and matrices as data frames The interaction between data frames and vectors and matrices.