Desktop Survival Guide
by Graham Williams
We have seen the Rattle interface throughout this chapter and we will now systematically introduce it: The interface is based on a set of tabs through which we progress as we work our way through a data mining project. For any tab, once we have set up the required information, we will click the Execute button to perform the actions. Take a moment to explore the interface a little. Notice the Help menu and find that the help layout mimics the tab layout.
The Rattle interface is designed as a simple interface to a powerful suite of underlying tools for data mining. The general process is to step through each tab, left to right, performing the corresponding actions. For any tab, we configure the options and then click the Execute button (or F2) to perform the appropriate tasks. It is important to note that the tasks are not performed until the Execute button (or F2 or the Execute menu item under Tools) is clicked.
The Status Bar at the base of the window will indicate when the action is completed. Messages from R (e.g., error messages, although many R error messages are captured by Rattle and displayed in a popup) will appear in the R Console from where Rattle was started. Since Rattle is a simple graphical interface sitting on top of R itself, it is important to remember that some errors encountered by R on loading the data (and in fact during any operation performed by Rattle) may be displayed in the R Console.
The R Code that Rattle passes on to R to execute underneath is recorded in the Log tab. This allows us to review the R commands that perform the corresponding data mining tasks. The R code snippets can be copied as text from the Log tab and pasted into the R Console from which Rattle is running, to be directly executed. This allows us to deploy Rattle for basic tasks, yet still give us the full power of R to be deployed as needed, perhaps through using more command options than exposed through the Rattle interface. This also allows us the opportunity to export the whole session as an R script file. The Log serves as a record of the actions taken, and allows those actions to be repeated directly and automatically through R itself at a later time. Simply click on the Export button to export the log to a file that will have the exttt.R extension.
We now traverse each of the main elements of the Rattle user interface, specifically the toolbar and menus. We begin with a basic concept--a project. Note that we have already talked about the nature of Rattle's main tab interface.