As we previously saw, domain checks are the ones related to the range of variation of our attributes. How could we perform these checks employing the R language? Even if different possible ways are available, we are going to look at one which can be considered as straightforward, a combined use of the range and unique functions. We are going to use them in order to derive the variation domain of numerical and character variables.
Let's start by looking at the numerical variables, how can we have a look at their range? We can employ the well named range function, which is going to give us back the minimum and maximum value within a sequence of numbers. For instance, applying it to a simple sequence from 1 to 10 will give us ...
