Converting a matrix to a data frame and a data frame to a matrix

A matrix is a two-dimensional arrangement of data with rows and columns where each row/column is of the same data type, either all numeric, all character, or all logical. Moreover, the number of elements in each column should be the same, and the number of elements in each row should also be the same.

A data frame is also a two-dimensional arrangement of data with rows and columns, but each column could be of very different types; for example, a data frame may contain both character and numeric columns. However, the number of elements in each column should be the same. Since both data structures share some common properties, they could be converted from one structure to another. In this recipe, you will learn to convert a matrix to a data frame and a data frame to a matrix.