Tạo bộ dữ liệu 2D tách được theo hướng xuyên tâm

#set number of variables and seed
n <- ___
set.seed(1)

#Generate data frame with two uniformly distributed predictors, x1 and x2
df <- data.frame(x1 = runif(n, min = ___, max = ___), 
                 x2 = runif(n, min = ___, max = ___))

#We want a circular boundary. Set boundary radius 
radius <- ___
radius_squared <- radius^2

#create dependent categorical variable, y, with value -1 or 1 depending on whether point lies
#within or outside the circle.
df$y <- factor(ifelse(df$___ + df$___ < radius_squared, -1, 1), levels = c(-1, 1))