How to subset data for a specific column with ddply?

Question

I would like to know if there is a simple way to achieve what I describe below using ddply. My data frame describes an experiment with two conditions. Participants

Answer 1

Using dplyr package:

library(dplyr)
df %>%
  group_by(Condition) %>%
  summarise(N = n(),
            nAccurate = sum(Accuracy),
            RT = mean(RT[Accuracy == 1]))