Hello friends, can anyone help me answering this question? I don't really know how to respond.
Question: Plot can be used to make regular old scatter plots. Why doesn't plot make a scatter plot when passed the object anovaOutput?
#runs an anova on my data and saves the out put
anovaOutput <- aov(Temp ~ Month, data = airquality)
#I plot the output of the anova
par(mfrow = c(2,2)) #this is just used to show the four graphs create by the next line.
Actually, the default behavior of the plot() function applied to an object of the aov or lm class is to plot diagnostic plots to check the quality of the annova. This happen because different plot methods are applied depending on the class. To know the class of your object, use class(anovaOutput). Then methods(plot) will list all the different methods available for the plot function. It is also possible to define your own methods for your newly defined classes. Also, to see what a method does, you can use the function getAnywhere():