removing dot ref before its explanation

episodes/06-data-visualization.Rmd

@@ -266,7 +266,7 @@ ggplot(data = variants, aes(x = POS, y = MQ, color = sample_id)) +
  geom_point() +
  labs(x = "Base Pair Position",
       y = "Mapping Quality (MQ)") +
- facet_grid(. ~ sample_id)
+ facet_grid(~ sample_id)
 ```
 
 This looks okay, but it would be easier to read if the plot facets were stacked vertically rather than horizontally. The `facet_grid` geometry allows you to explicitly specify how you want your plots to be arranged via formula notation (`rows ~ columns`; the dot (`.`) indicates every other variable in the data i.e., no faceting on that side of the formula).
@@ -395,7 +395,7 @@ for inspiration. Here are some ideas:
 
 - See if you can change the size or shape of the plotting symbol.
 - Can you find a way to change the name of the legend? What about its labels?
-- Try using a different color palette (see the [Cookbook for R](https://www.cookbook-r.com/Graphs/Colors_\(ggplot2\)/).
+- Try using a different color palette (see the [Cookbook for R](https://www.cookbook-r.com/Graphs/Colors_\(ggplot2\)/)).
 
 
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