Creating a Scatterplot

Now let's take a look at what factors might influence Drug, the target variable. As a researcher, you know that the concentrations of sodium and potassium in the blood are important factors. Since these are both numeric values, you can create a scatterplot of sodium versus potassium, using the drug categories as a color overlay.

Place a Plot node in the workspace and connect it to the Source node, and double-click to edit the node.

Figure 1. Stream with plot node
Stream with plot node
Figure 2. Creating a scatterplot
Creating a scatterplot

On the Plot tab, select Na as the X field, K as the Y field, and Drug as the overlay field. Then, click Run.

The plot clearly shows a threshold above which the correct drug is always drug Y and below which the correct drug is never drug Y. This threshold is a ratio--the ratio of sodium (Na) to potassium (K).

Figure 3. Scatterplot of drug distribution
Scatterplot of drug distribution

Next