Draw Boxplot with Means in R (2 Examples) | Add Mean Values | points, text & stat_summary [ggplot2]

R code of this video:

group = LETTERS[1:4])

data_means ＜- aggregate(data$values, # Means by group
list(data$group),
mean)

boxplot(data$values ~ data$group) # Draw boxplot in Base R
points(x = 1:nrow(data_means), # Add points to plot
y = data_means$x,
col = "red",
pch = 16)
text(x = 1:nrow(data_means), # Add text to plot
y = data_means$x - 0.15,
labels = paste("Mean:", round(data_means$x, 1)),
col = "red")

library("ggplot2")

ggplot(data, aes(x = group, y = values)) + # Draw ggplot2 boxplot
geom_boxplot() +
stat_summary(fun = mean, geom = "point", col = "red") + # Add points to plot
stat_summary(fun = mean, geom = "text", col = "red", # Add text to plot
vjust = 1.5, aes(label = paste("Mean:", round(..y.., digits = 1))))

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[inaydweller]

thanks! was very usefull with my college stuff!!

[czr]

Took me out of my 2 hours serch! short and just what I needed! Master!

[johannafedorovsky]

Super clear and useful! How would you do to add Mean+SD as label? Is there a way to add the number of observations for each group? Thanks

[cchen]

Thanks! Do you perhaps know how to show the different means for each boxplot, in the case you add a third binomial variable on the graph (aes= x, y, fill=z)? In this case, the means stay in the middle of both boxplots and are not placed on their own boxplots...

[russtin]

What does the ..y.. accomplish in the round function?