2.9 Troubleshooting

Problem: Missing data showing up as a category in ggplot?

Get rid of that far right bar!

Solution: Use dplyr to select only the variables you are going to plot, then pipe in the na.omit() at the end. It will create a temporary data frame (e.g) plot.data that you then provide to ggplot().

Problem: Got numerical binary 0/1 data but want to plot it as categorical? > Other related error messages: > * Continuous x aesthetic – did you forget aes(group=…)?

Consider a continuous variable for the number of characters in an email num_char, and a 0/1 binary variable spam.

Solution: Create a second variable var_factor for plotting and keep the binary var as 0/1 for analysis.

Problem: You want to change the legend title for a fill or color scale.

Solution: Add the name= argument to whatever layer you added that created the legend. Here I speciefied a fill, and it was a discrete variable. So I use the scale_fill_discrete() layer.

Here, I colored the points by a discrete variable, so the layer is scale_color_discrete().

Problem: You want to add means to boxplots. Boxplots are great. Even better with violin overlays. Know what makes them even better than butter? Adding a point for the mean. stat_summary is the layer you want to add. Check out this stack overflow post for more context.

I suggest playing around with size and plotting character pch to get a feel for how these work. You can also look at ?pch (and scroll down in the help file) to see the 25 default plotting characters.