Don't use parallel=True in smooth_knn_dist since it makes performance worse.
@@ -45,7 +45,7 @@ MIN_K_DIST_SCALE = 1e-3
NPY_INFINITY = np.inf
-@numba.njit(parallel=True, fastmath=True)
+@numba.njit(fastmath=True) # benchmarking `parallel=True` shows it to *decrease* performance
def smooth_knn_dist(distances, k, n_iter=64, local_connectivity=1.0, bandwidth=1.0):
"""Compute a continuous version of the distance to the kth nearest
neighbor. That is, this is similar to knn-distance but allows continuous
