Lookup Tables
Replacing values with other values in R.
- Remember that if there are NA values, change them with
replace_na.
Lookup List
Using a list with names gets the job done, but I do not think it is
very efficient. You can make a function or use list access [...].
how_often_1 = c("A","B","C","Long month","E","F")
how_often_lookup = set_names(seq_along(how_often_1),how_often_1)
Examples:
ex= c("E","B","Long month","A","B","B")
how_often_lookup["E"]
how_often_lookup[ex]
often_to_number <- function(x) how_often_lookup[x]
often_to_number(ex)
Lookup Table
Use a left join. You will have to make sure the column names
match. Use rename if you want to change the value column name.
gpa_values <- tribble(
~grade, ~value,
"A" , 4,
"B" , 3,
"C" , 2,
"D" , 1,
"F" , 0,
)
Example usage:
grades <- tribble(
~person, ~science_grade,
"Amanda", "A",
"Gunn", "B",
"Santiago", "A",
"Carmen", "F",
"Isabel", "D",
"Allende","C",
"Ghost", NA,
)
grades %>%
left_join(gpa_values, by=c("science_grade"="grade")) %>%
rename(science_gp = value)