r rename columns

colnames(trSamp)[2] <- "newname2"

my_data %>% 
  rename(
    sepal_length = Sepal.Length,
    sepal_width = Sepal.Width
    )

# Rename column by name: change "beta" to "two"
names(d)[names(d)=="beta"] <- "two"
d
#>   alpha two gamma
#> 1     1   4     7
#> 2     2   5     8
#> 3     3   6     9

# You can also rename by position, but this is a bit dangerous if your data
# can change in the future. If there is a change in the number or positions of
# columns, then this can result in wrong data.

# Rename by index in names vector: change third item, "gamma", to "three"
names(d)[3] <- "three"
d
#>   alpha two three
#> 1     1   4     7
#> 2     2   5     8
#> 3     3   6     9

library(plyr)
rename(d, c("beta"="two", "gamma"="three"))
#>   alpha two three
#> 1     1   4     7
#> 2     2   5     8
#> 3     3   6     9

colnames(df)[colnames(df) == "name"] <- "new_name"

# df = dataframe
# old.var.name = The name you don't like anymore
# new.var.name = The name you want to get

names(df)[names(df) == 'old.var.name'] <- 'new.var.name'

df <- rename(df, new_name = old_name) #For renaming dataframe column
 
tbl <- rename(tbl, new_name = old_name) #For renaming tibble column
 
tbl <- tbl %>% rename(new_name = old_name) #For renaming tibble column using dplyrpipe 
                                           #operator 

colnames(df)[which(names(df) == "columnName")] <- "newColumnName"

rename(df, !!metric:=value)