r summarize_if with multiple conditions

Question

我想把一个df的观测值减少到一个观测值（单行）.我想summaryize_if是数值与平均值，if是字符串或因子与模式。下面的代码不工作，但我希望它给出了想法.谢谢！我想把一个df的观测值减少到一个单一的观测值（单行）。

#data frame
num <- c(1:7)
str <- c("toy","control","play",NA,"give","toy","toy")
df_finale <- data.frame(num,str)

#mode function
Mode <- function(x) {
        ux <- unique(x)
        ux[which.max(tabulate(match(x, ux)))]
}

#df reduction
df_finale <- df_finale %>%
                    summarize_if(is.numeric, mean, na.rm = TRUE) %>%
                    summarize_else_if(!is.numeric, Mode)

Answer 1

一种可能是。

df_finale %>%
 summarise_all(~ if(is.numeric(.)) mean(., na.rm = TRUE) else Mode(.))

  num str
1   4 toy

Answer 2

我们可以使用 mutate_if 与 distinct

library(dplyr)
library(purrr)
df_finale %>%
     mutate_if(is.numeric, mean, na.rm = TRUE) %>% 
     mutate_if(negate(is.numeric), Mode) %>%
     distinct
#   num str
#1   4 toy

---

或与 across/summarise 从新版的 dplyr

i1 <- df_finale %>% 
           summarise_all(is.numeric) %>%
           flatten_lgl

df_finale %>% 
     summarise(across(names(.)[i1], ~ mean(., na.rm = TRUE)), 
               across(names(.)[!i1], Mode))