subsetting.r

library(microbenchmark)

microbenchmark(
  mtcars["Volvo 142E", "carb"],
  mtcars[32, 11],
  mtcars[[c(11, 32)]],
  mtcars[["carb"]][32],
  mtcars[[11]][32],
  mtcars$carb[32],
  .subset2(mtcars, "carb")[32],
  .subset2(mtcars, 11)[32]
)
# Unit: nanoseconds
#                          expr   min      lq  median      uq   max neval
#  mtcars["Volvo 142E", "carb"] 22048 23630.0 24337.5 25206.5 50470   100
#                mtcars[32, 11] 19715 20807.0 21422.0 21945.0 99536   100
#           mtcars[[c(11, 32)]]  8302  9334.0  9818.0 10455.5 14462   100
#          mtcars[["carb"]][32]  8049  8832.5  9357.5 10180.0 20883   100
#              mtcars[[11]][32]  7867  8686.0  9326.0  9922.0 18266   100
#               mtcars$carb[32]  2358  3055.5  3321.0  3542.5  8411   100
#  .subset2(mtcars, "carb")[32]   515   754.0   825.5   930.5  1439   100
#      .subset2(mtcars, 11)[32]   362   610.5   679.0   755.0  2568   100#