r - 将以英寸为单位的高度字符向量转换为厘米？

Question

我得到一个字符向量:

tibble(H = c("6'2\"", "5'10\"", "5'5\"", "5'1\"", "5'5\"", "5'4\""))

我想把它转换成厘米。

请告知我该怎么做？

Answer 1

有几种方法可以使用

1) 粘贴成单个字符串后用 fread 读取

library(data.table)
fread(paste(sub('"', "", df1$H), collapse="\n"), sep="'")[, 
               as.matrix(.SD) %*% c(30.48, 2.54)][,1]
 #[1] 187.96 177.80 165.10 154.94 165.10 162.56

2) 使用 gsubfn

library(gsubfn)
as.numeric(gsubfn("(\\d)'(\\d+)", ~ as.numeric(x) * 30.48 + 
            as.numeric(y) * 2.54, sub('"', '', df1$H)))
 #[1] 187.96 177.80 165.10 154.94 165.10 162.56

3) 与 分开

library(tidyverse)
df1 %>% 
    separate(H, into = c("H1", "H2"), convert = TRUE) %>%
    transmute(H = H1 * 30.48 + H2 * 2.54)
# A tibble: 6 x 1
#      H
#  <dbl>
#1  188.
#2  178.
#3  165.
#4  155.
#5  165.
#6  163.

4) 与 measurements

library(measurements)
library(tidyverse)
df1 %>% 
   separate(H, into = c("H1", "H2"), convert = TRUE) %>%
   transmute(H = conv_unit(H1, "ft", "cm") + conv_unit(H2, "inch", "cm"))