如何使用dplyr:：mutate对tible列中的数字进行四舍五入

我有以下几点：

library(tidyverse)
tb <- structure(list(V2 = structure(c(2L, 1L, 4L, 3L, 2L, 1L, 4L, 3L
), .Label = c("bar", "foo", "gop", "qux"), class = "factor"), 
    V3m = c(9.394981, 6.826405, 1.074885, 1.493691, 1e-04, 2e-04, 
    3e-04, 4e-04)), class = c("tbl_df", "tbl", "data.frame"), row.names = c(NA, 
-8L), .Names = c("V2", "V3m"))

我们可以使用sprintf

使用@Eric Fail编辑的可复制示例

titanic_4
# A tibble: 6 x 1
#   perc_survived
#           <dbl>
#1      50.00000
#2     100.00000
#3      97.14286
#4      44.44444
#5     100.00000
#6      19.23077

titanic_4 <- titanic_4 %>% 
               mutate(perc_survived_6 = sprintf("%0.6f", perc_survived))
titanic_4
# A tibble: 6 x 2
#   perc_survived perc_survived_6
#           <dbl>           <chr>
#1      50.00000       50.000000
#2     100.00000      100.000000
#3      97.14286       97.142857
#4      44.44444       44.444444
#5     100.00000      100.000000
#6      19.23077       19.230769

数据 我们可以使用sprintf

使用@Eric Fail编辑的可复制示例

titanic_4
# A tibble: 6 x 1
#   perc_survived
#           <dbl>
#1      50.00000
#2     100.00000
#3      97.14286
#4      44.44444
#5     100.00000
#6      19.23077

titanic_4 <- titanic_4 %>% 
               mutate(perc_survived_6 = sprintf("%0.6f", perc_survived))
titanic_4
# A tibble: 6 x 2
#   perc_survived perc_survived_6
#           <dbl>           <chr>
#1      50.00000       50.000000
#2     100.00000      100.000000
#3      97.14286       97.142857
#4      44.44444       44.444444
#5     100.00000      100.000000
#6      19.23077       19.230769

数据

---

我们是要将其舍入还是只显示X位数？@zx8754 9.394981到9.39和0.000100到0.00tb%>%mutateV3mR=roundV3m，2@AdamQuek我认为他们不需要舍入.tb%>%mutateV3mR=formatCV3m，format=f，digits=2？我们是要舍入还是只显示X个数字？@zx8754 9.394981到9.39和0.000100到0.00tb%>%mutateV3mR=roundV3m，2@AdamQuek我认为他们不需要round.tb%>%mutateV3mR=formatCV3m，format=f，digits=2？

tb %>% 
   mutate(V3mr = sprintf("%0.2f", V3m))

titanic_4
# A tibble: 6 x 1
#   perc_survived
#           <dbl>
#1      50.00000
#2     100.00000
#3      97.14286
#4      44.44444
#5     100.00000
#6      19.23077

titanic_4 <- titanic_4 %>% 
               mutate(perc_survived_6 = sprintf("%0.6f", perc_survived))
titanic_4
# A tibble: 6 x 2
#   perc_survived perc_survived_6
#           <dbl>           <chr>
#1      50.00000       50.000000
#2     100.00000      100.000000
#3      97.14286       97.142857
#4      44.44444       44.444444
#5     100.00000      100.000000
#6      19.23077       19.230769

titanic_4 <- tibble(perc_survived = c(50.000000,
          100.000000, 97.142857, 44.444444, 100.000000, 19.230769))