dummy.code {psych} | R Documentation |
Given a variable x with n distinct values, create n new dummy coded variables coded 0/1 for presence (1) or absence (0) of each variable. A typical application would be to create dummy coded college majors from a vector of college majors.
dummy.code(x)
x |
A vector to be transformed into dummy codes |
When coding demographic information, it is typical to create one variable with multiple categorical values (e.g., ethnicity, college major, occupation). dummy.code
will convert these categories into n distinct dummy coded variables.
If using dummy coded variables as predictors, remember to use n-1 variables.
A matrix of dummy coded variables
William Revelle
new <- dummy.code(sat.act$education) new.sat <- data.frame(new,sat.act) round(cor(new.sat,use="pairwise"),2)