library(dplyr) x %>% group_by(Category) %>% summarise(Frequency = sum(Frequency)) #Source: local data frame [3 x 2] # # Category Frequency #1 First 30 #2 ... ... <看更多>

Summarise each group to fewer rows. #'. #' @description. #' `summarise()` creates a new data frame. It will have one (or more) rows for. ... <看更多>

... learning how to use the group_by() function in conjunction with the summarize() verb that we learned previously. Hide. library(dplyr) library(babynames). ... <看更多>

Since you are manipulating a data frame, the dplyr package is probably the faster way to do ... test elapsed relative 1 ddply(dtf, ~group, plyr:::summarise, ... ... <看更多>