Looks between [-1, 1]
grad_est_subspace(f, r, m, M = NULL, scale = FALSE)A list with sub, the active subspace, sv, the singular values (all m of them), fs, which gives function values, gs, function grads, and X, which gives sampled locations.
The function to eval
The max dim of the active subspace
The dimension of the underlying/embedding space.
optional budget of evaluations, default to 2 * r * log(m)
Scale all gradients to have norm 1?