Question

I’m doing some clustering research and need to generate synthetic data that would look something like these examples:

We have 2d plots with 2 classes (red and black). How could I generate 2D data like this? It has a V structure, so I was thinking about generating points around straight lines – is there a way to do that in R?
I’m using R, but am open to other tools (just data has to be exportable).

Answer 1

Here’s a thought.

n <- c(200,200)                 # Number of points in each class
cls <- rep(1:2, n)              # Class memberships
i <- c(.2-.12*abs(rnorm(n[1])), # Noiseless x position
       -.2+.12*abs(rnorm(n[2])))
noise <- .04*(.2-abs(i))        # Noise level relative to `i`

# Final sample
x <- cbind(i, abs(.5*i)) + noise*matrix(rnorm(sum(n)*2), sum(n), 2)

plot(x[,1], x[,2], col=cls)