使用R重命名df值

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

Answer 1

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

Answer 2

Do you need to use dplyr?

Easy enough with gsub:

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

Answer 3

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"

Answer 4

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