Reshaping a table
Data frames are composed of rows and columns, and we already know that data that is considered tidy has one observation per row and one variable per column. However, data is everywhere, being generated by different kinds of sensors, machines, devices, and people. Naturally, not all that data will come to you in a perfectly beautiful, tidy format. Many will be the time when you will face messy datasets.
One of the things that can happen is to receive datasets in a wide format. As the name already suggests, this data comes with variables spread along the rows instead of columns, meaning that measurements from the same variable can be displayed on different columns. A common example of a wide formatted dataset is a monthly report with a column for the description of a project, followed by a column with the expense amount for each month, as shown in Figure 8.29.
Figure 8.29 – Projects dataset in wide format
A data frame in a wide shape...
