Question

我有一组列，我需要一个新列min123，其中列123a_1到123a_5的最小值。

dff <- structure(list(`MCI ID` = c("070405344", "230349820", "260386435","370390587", "380406805", "391169282", "440377986", "750391394","890373764", "910367024"), 
                      `123a_1` = structure(c(16672, 16372,16730, 16688, 16700, 16783, 16709, 17033, 16786, 16675), class = "Date"),
                      `123a_2` = structure(c(17029, 16422, 17088, 17036, 17057,17140, 17072, 17043, 17141, 17038), class = "Date"), 
                      `123a_3` = structure(c(NA_real_,NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_,NA_real_, NA_real_, NA_real_), class = "Date"), 
                      `123a_4` = structure(c(NA_real_,NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_,NA_real_, NA_real_, NA_real_), class = "Date"), 
                      `123a_5` = structure(c(NA_real_,NA_real_, NA_real_, NA_real_, NA_real_, NA_real_, NA_real_,NA_real_, NA_real_, NA_real_), class = "Date")), 
         .Names = c("MCI ID","123a_1", "123a_2", "123a_3", "123a_4", "123a_5"), row.names = c(NA,10L), class = "data.frame")

Answer 1

使用do.call和pmin的基础R方法：

dff$min123 <- do.call(pmin, c(dff[-1], na.rm = TRUE))

dplyr中的类似appraoch：

library(dplyr)    
dff %>% 
  mutate(min123 = do.call(pmin, c(select(., -1), na.rm = TRUE)))

或data.table：

library(data.table)
setDT(dff)[, min123 := do.call(pmin, c(.SD, na.rm = TRUE)), .SDcols = -1]

Answer 2

library(dplyr)    
dff %>% 
    mutate(min123 = pmin(`123a_1`, `123a_2`, `123a_3`, `123a_4`, `123a_5`, na.rm = T))

Answer 3

这就是函数$ python3 Python 3.5.2 (default, Nov 17 2016, 17:05:23) [GCC 5.4.0 20160609] on linux Type "help", "copyright", "credits" or "license" for more information. >>> input="Billy got score of 2 and Tommy got score of 3" >>> import re >>> re.split(r'score of \d+(?:\s*and\s*)?',input) ['Billy got ', 'Tommy got ', '']的用途：

pmin

列组中的最小值返回值

3 个答案: