R dplyr summarise multiple functions to selected variables

Question

I have a dataset for which I want to summarise by mean, but also calculate the max to just 1 of the variables.

Let me start with an example of what I would like to a

Answer 1

I was looking for something similar and tried the following. It works well and much easier to read than the suggested solutions.

iris %>% 
group_by(Species) %>%
filter(Sepal.Length > 5) %>% 
summarise(MeanSepalLength=mean(Sepal.Length), 
MeanSepalWidth = mean(Sepal.Width),
MeanPetalLength=mean(Petal.Length),
MeanPetalWidth=mean(Petal.Width), 
MaxPetalWidth=max(Petal.Width))

# A tibble: 3 x 6
Species    MeanSepalLength MeanSepalWidth MeanPetalLength MeanPetalWidth MaxPetalWidth
                                                        
1 setosa                5.01           3.43            1.46          0.246           0.6
2 versicolor            5.94           2.77            4.26          1.33            1.8
3 virginica             6.59           2.97            5.55          2.03            2.5

In summarise() part, define your column name and give your column to summarise inside your function of choice.