How to produce different geom_vline in different facets in R?

user_5750741 0
Viewed 16268

I am trying to produce 2 different geom_vlines with different colours in 2 different facets of a dataset. I am doing this to highlight means of 2 different facets.

Here's the dataset:

Pclass  Sex    Age  SibSp   Parch   Fare    Cabin   Embarked    Survived
  3     male    22   1        0     7.25                S          0    
  1     female  38   1        0    71.2833   C85        C          1
  3     female  26   0        0     7.925               S          1    
  1     female  35   1        0    53.1     C123        S          1
  3     male    35   0        0     8.05                S          0    
  1     male    54   0        0    51.8625   E46        S          0

Here's the code:

g<-ggplot(data = train3, aes(x = Age, y = Survived, colour = factor(Pclass)))
g<-g+facet_wrap(~Sex)
g<-g+geom_point(size = 4, alpha = 0.2)+ggtitle("Survival by Gender")+theme(plot.title = element_text(hjust = 0.5))
g<-g+geom_vline(data = subset(train3,Sex=="female"), xintercept = mean(train3[which(train3$Sex=="female"),3]), colour = "pink", size = 1)
g<-g+geom_vline(data = subset(train3,Sex=="male"), xintercept = mean(train3[which(train3$Sex=="male"),3]), colour = "blue", size = 1)
g

Here's the output

enter image description here

I actually want to produce only 1 vline in each facet: pink in female and blue in male.

The suggestion give here is not working either . Error shown being: 

Error in .(Sex == "female") : could not find function "."
geom-hline facet-wrap ggplot2 r
3 Answers

Building on @Sébastien Rochette's answer above; Rather than creating a new data frame dataInt with the function summarize(Int = mean(Age)), which didn't work for me as I had multiple levels within each facet plot, use mutate instead.

train3 <- train3 %>%
  group_by(Sex) %>%
  mutate(Int = mean(Age))

And then you can use train3 data-frame in 

g<-ggplot(data = train3, aes(x = Age, y = Survived, colour = factor(Pclass))) + 
  facet_wrap(~Sex) +
  geom_vline(data=train3, xintercept=Int)

This works but I fear it may have created a geom_vline for all values, because each mean will be repeated within each level of each factor within the dataframe.

user_39190210
Related