Indicate levels by key R factors

Question

I am just starting to learn R and trying to use factors and levels for categorical data.

A simple example:

survey_vector <- c("M", "F", "F", "M", "M")
factor_survey_vector <- factor(survey_vector)
levels(factor_survey_vector) <- c("Female", "Male")
factor_survey_vector

This works fine, and I get output like:

[1] Male Female Female Male Male
Levels: Female Male

However, here I have to specify the levels in sorted order, and I would like it to be more explicit. I tried something like:

levels(factor_survey_vector) <- c(M="Male", F="Female")

However, this does not work properly.

Answer 1

Of the ?levelsimportant points in bold:

Using

levels(x)

levels(x) <- value

Arguments

x an object, for example a factor.

value levels(x). NULL . -, , , x, list, , .

:

## same, using a named list
z <- gl(3, 2, 12)
levels(z) <- list(A = c(1,3), B = 2)
z

, , - , .

, , :

levels(factor_survey_vector) <- list(Male="M",Female="F")