Читать книгу Industrial Data Analytics for Diagnosis and Prognosis - Yong Chen - Страница 22

In a scatter plot, each observation is represented by a point whose coordinates are the values for the two variables of this observation. The following R codes draw the scatter plot for two numerical variables, horsepower and highway.mpg, of the auto_spec data set.

plot(auto.spec.df$highway.mpg ~ auto.spec.df$horsepower,

xlab = "Horsepower", ylab = "Highway MPG")

The obtained scatter plot is shown in Figure 2.4. It can be seen from the scatter plot that a general trend exists in the relationship between the highway MPG and the horsepower, where a car with higher horsepower is more likely to have a lower highway MPG.

Figure 2.4 Scatter plot of highway MPG versus horsepower.