R create column based on specific columns-CodePudding

I have iris dataframe, I want a function that create/replace a new/existing column by combining others, this function has 2 parameters : name of the new column and names of columns to combine.

for example I want to combine Petal.Width and Species : I tried :

func <- function(data, names, column_names){
data <- data %>% mutate_at(vars(column_names), names = paste0(column_names))
}

iris <- func(iris, "Petal.Width", c("Petal.Width","Species"))

Honestly I don't know how to deal with variables that must be considered like names.

The result should be :

iris$Petal.Width <- paste0(iris$Petal.Width, iris$Species)

Do you have an idea?

CodePudding user response：

You can use rlang::syms to convert your character values to symbols. And then can use !!! and := to inject them into the call

func <- function(data, names, column_names){
  column_names <- syms(column_names)
  data %>% mutate("{names}" := paste0(!!!column_names))
}

func(iris, "Petal.Width", c("Petal.Width","Species"))

For more suggestions on creating your own functions that use dplyr, see the programming with dplyr guide