创建一个范围内有间隙的序列

Question

我试图在一个范围内创建一系列数字,跳过每4个数字.我知道它可能涉及seq或seq_len不知何故,但我似乎无法直截了当.

序列应该是这样的:

c(1,2,3,5,6,7,9,10,11...48)

Answer 1

另外一个选项:

x <- 1:48
x[-seq.int(0L, length(x), 4L)]

基准

x <- 1:48e6

library(microbenchmark)
mbm <- microbenchmark(
  steven    = x[-seq.int(0L, length(x), 4L)],
  venyao    = x[x %% 4 != 0],
  venyao2   = as.vector(matrix(x, nrow=4)[-4, ]),
  pascal    = x[as.logical((x) %% 4)],
  user20650 = as.integer(matrix(x, nrow=4)[-4, ]),
  times = 10
)

#Unit: milliseconds
#      expr       min        lq      mean    median        uq       max neval  cld
#    steven  326.2159  350.6567  354.2743  357.3672  359.9924  368.3123    10 a   
#    venyao 1388.9975 1395.8814 1417.3213 1400.1432 1455.2255 1470.7743    10    d
#   venyao2  613.9878  637.5377  639.1718  637.9342  640.1753  657.6627    10  b  
#    pascal 1236.6055 1243.8149 1265.1976 1249.1046 1304.5699 1316.8247    10   c 
# user20650  587.8511  596.5614  610.4037  602.3607  619.1915  670.8756    10  b