How to calculate a median and mean of 95 percentile in R

Question

My dataset contains multiple observations (Mean Intensity gfp) for different species (aapl2). Each species has a several number of observations.

I have already grouped observations in groups by species and calculated 95 percentil with:

data2 = aggregate(data$"Mean Intensity gfp" ~ data$aapl2, FUN = quantile, probs = c(0.95)).

But now, I have problem and I don't know how to solve it. I need to calculate a median and mean of calculated 95 percentile , but I really don't know how to do it.

Could somebody help me, please?

Thank you very very much

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Answer 1

Using iris... To get the mean/median of those where the value is below the 95th percentile (of its species)

library(data.table)
data.table(iris)[, keep := Petal.Length < quantile(Petal.Length, 0.95), 
                   by = Species][
                   keep==TRUE, 
                   .(mean(Petal.Length), median(Petal.Length)), 
                   by = Species]

And using dplyr

library(dplyr)
iris %>% 
  group_by(Species) %>%
  filter(Petal.Length < quantile(Petal.Length, 0.95)) %>%
  summarize("mean"=mean(Petal.Length), 
            "med"=median(Petal.Length))