Rename df values using R

Question

I have a dataframe as following :

df <- data.frame(month = c("mazda miata 2017", "honda civic 2017"),
                 april = c(.1,.2),
                 may = c(.1,.2)) 

        month april may
1     miata     0.1 0.1
2     civic     0.2 0.2

I would like to rename mazda 3 as mazda and honda civic as honda. How can this be done using dplyr

score 2 · Accepted Answer · answered Sep 14 '18 at 19:33

2

Since you mention dplyr

library(dplyr)
library(tidyr)
df%>%tidyr::separate(month, c("month","Drop"), " ")%>%select(-Drop)
  month april may
1 mazda   0.1 0.1
2 honda   0.2 0.2

answered Sep 14 '18 at 19:33

BENY

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I just realized after your answer on if I have a bigger text and just want that part how to do it. Modified my question. The point being I dont want the first word always.Thank you. – SNT Sep 14 '18 at 19:37
@SNT You may need to explain more , do you have something , like Honda CRV 1.1 so you want the CRV out put ? Or maybe AUdi Q5 you want Q5 output ? – BENY Sep 14 '18 at 19:41
I actually have it like `"Marlboro Gold Mainline", "Marlboro Red Mainline", "Marlboro Green Mainline","Marlboro Black Menthol", "Marlboro Black Non-Menthol"` . So I want the names to be `Gold,Red,Green,Black Menthol, Black Non-Menthol` – SNT Sep 14 '18 at 19:43
@SNT `df%>%tidyr::separate(month, c('Drop','month')," ")%>%select(-Drop)` is this work for you ? – BENY Sep 14 '18 at 19:47
Wow :) simply Wow :) Thank you Wen. – SNT Sep 14 '18 at 19:53
@ Wen I do run into an issue . Both `"Marlboro Black Menthol", "Marlboro Black Non-Menthol"` return as `Black,Black` whereas I would like them be like `"Black Menthol", "Black Non-Menthol"` – SNT Sep 14 '18 at 20:09
@SNT how about `Marlboro Red Mainline` should it be `Red Mainline` – BENY Sep 14 '18 at 20:10
Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/180071/discussion-between-snt-and-wen). – SNT Sep 14 '18 at 20:11
@SNT Sorry I can not using the stack chat – BENY Sep 14 '18 at 20:11
It comes up as Red and I am fine with it – SNT Sep 14 '18 at 20:12
@SNT how about `df%>%tidyr::separate(month, c('Drop','month')," ",extra = 'merge')%>%select(-Drop)` – BENY Sep 14 '18 at 20:16
That adds those words but it also add `Mainline` after green and red which I dont want to.The reason being I have two df one of them as `red mainline,green mainline,black menthol and black non-menthol` and then another df I have `red special,green special,black menthol and black non-menthol` . I eventually want to merge these based on `red,green,black menthol,black non-menthol` – SNT Sep 14 '18 at 20:30
is their a way I can replace `mainline` and `special` by using gsub or something – SNT Sep 14 '18 at 20:32
@SNT gsub("mainline ", "", yourcolum) – BENY Sep 14 '18 at 20:40
I did this `gsub("Mainline", "", Secondary_family) %>%` and I get an error `object 'Secondary_family' not found` . Am I doing something wrong with gsub – SNT Sep 14 '18 at 20:48
@SNT check this one https://stackoverflow.com/questions/11936339/replace-specific-characters-within-strings – BENY Sep 14 '18 at 21:07

score 0 · Answer 2 · answered Sep 14 '18 at 19:22

0

Do you need to use dplyr?

Easy enough with gsub:

df$month <- gsub("honda civic", "honda", df$month)

answered Sep 14 '18 at 19:22

chatwon

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score 0 · Answer 3 · edited Sep 14 '18 at 23:21

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You can use the following solution to solve your problem:

levels(df$month)[levels(df$month )=="mazda 3"] <- "mazda"
levels(df$month)[levels(df$month )=="honda civic"] <- "honda"

edited Sep 14 '18 at 23:21

Grant Miller

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answered Sep 14 '18 at 19:22

Shirin Yavari

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score 0 · Answer 4 · answered Sep 16 '18 at 01:38

Try a simple regular expression with str_replace.

In the example below, replace "mazda " and "honda" with anything else you'd like to eliminate. Separate with the OR symbol |:

 df %>% 
   mutate(month = str_replace(month, "mazda |honda ", "") )

       month april may
1 miata 2017   0.1 0.1
2 civic 2017   0.2 0.2

Rename df values using R

4 Answers4