R lang: First letter to upper case

Question

I'm trying to convert all data in the column to "First letter to upper case" The following code replaces all data with the first row,

simpleCap <- function(x) {
  s <- strsplit(x, " ")[[1]]
  paste(toupper(substring(s, 1,1)), substring(s, 2),
        sep="", collapse=" ")
}
allDestination$Categories <- simpleCap(allDestination$Categories)

Sample data

japan/okinawa/okinawa-other-islands
japan/hokkaido/hokkaido-north/furano-biei-tomamu
japan/hokkaido/hokkaido-north/asahikawa-sounkyo
japan/hokkaido/hokkaido-north/wakkanai-rishiri-rebun
japan/hokkaido/hokkaido-east/kushiro-akan-nemuro

The function code sample comes from First letter to upper case

How to make the function as "column compatible" instead of only replacing only a single value?

Your function explicitly works on the first element by using `[[1]]`. Instead, keep `s` as a `list`, and operate over all of it with `sapply`. — r2evans, Jul 01 '18 at 02:11
You could use the `capitalize` function from the `Hmisc` package — GordonShumway, Jul 01 '18 at 04:59
You can `vectorize` your function. The simple way can be as `simpleCapV <- Vectorize(simpleCap)` . Now use `simpleCapV(allDestination$Categories)`. — MKR, Jul 01 '18 at 07:51
What do you mean by repeated results of the first row?. Can you post the results you need? — Onyambu, Jul 01 '18 at 15:16

score 5 · Answer 1 · answered Aug 23 '18 at 15:22

Tidyverse Answer - There is a function specifically for this stringr::str_to_title

library(tidyverse)

data example:

data_1 <- 
  data.frame("japan/okinawa/okinawa-other-islands",
             "japan/hokkaido/hokkaido-north/furano-biei-tomamu",
             "japan/hokkaido/hokkaido-north/asahikawa-sounkyo",
             "japan/hokkaido/hokkaido-north/wakkanai-rishiri-rebun",
             "japan/hokkaido/hokkaido-east/kushiro-akan-nemuro",
             stringsAsFactors=FALSE)

function at work:

> str_to_title(data_1)

[1] "Japan/Okinawa/Okinawa-Other-Islands"                 
[2] "Japan/Hokkaido/Hokkaido-North/Furano-Biei-Tomamu"    
[3] "Japan/Hokkaido/Hokkaido-North/Asahikawa-Sounkyo"     
[4] "Japan/Hokkaido/Hokkaido-North/Wakkanai-Rishiri-Rebun"
[5] "Japan/Hokkaido/Hokkaido-East/Kushiro-Akan-Nemuro"

https://stringr.tidyverse.org/reference/case.html

Onyambu · Accepted Answer · 2018-07-01T05:05:44.417

You can use a negative look behind, to capitalize every letter which is preceded by a non letter or is at the beginning of the sentence ie (?:^|(?<=\\W))(.) or also you can think of it as to capitalize a letter which is not preceded by a letter ie (?<!\\w)(.)

gsub("(?<!\\w)(.)","\\U\\1",dat1$V1,perl = TRUE) 

[1] "Japan/Okinawa/Okinawa-Other-Islands"                 
[2] "Japan/Hokkaido/Hokkaido-North/Furano-Biei-Tomamu"    
[3] "Japan/Hokkaido/Hokkaido-North/Asahikawa-Sounkyo"     
[4] "Japan/Hokkaido/Hokkaido-North/Wakkanai-Rishiri-Rebun"
[5] "Japan/Hokkaido/Hokkaido-East/Kushiro-Akan-Nemuro"

data:

 dat1=read.table(strip=T,text="japan/okinawa/okinawa-other-islands
       japan/hokkaido/hokkaido-north/furano-biei-tomamu
       japan/hokkaido/hokkaido-north/asahikawa-sounkyo
       japan/hokkaido/hokkaido-north/wakkanai-rishiri-rebun
       japan/hokkaido/hokkaido-east/kushiro-akan-nemuro")

using `gsub("(?<!\\w)(.)","\\U\\1", tolower(dat1$V1), perl = TRUE)` would be robust to entries like `JAPAN/HOKKAIDO/HOKKAIDO/NORTH/FURANO/BIEI/ROMARU`. — Cris, May 27 '22 at 20:54

R lang: First letter to upper case

2 Answers2