Determines which columns from the original input space contribute (have non-zero influence) to any of the output components of the projector.
variables_used(x, ...)# S3 method for composed_projector
variables_used(x, tol = 1e-08, ...)
A sorted numeric vector of unique indices corresponding to the original input variables.
A projector object (e.g., projector, composed_projector).
Additional arguments passed to specific methods.
Numeric tolerance for determining non-zero coefficients. Default is 1e-8 for some methods. Passed via ....