brainspace.null_models.spin.spin_permutations¶

brainspace.null_models.spin.spin_permutations(spheres, data, unique=False, n_rep=100, random_state=None, surface_algorithm='FreeSurfer')[source]¶

Generate null data using spin permutations.

Parameters:

spheres (dict[str, ndarray or BSPolyData], BSPolyData or ndarray) – Dictionary of points in a sphere, for left (‘lh’ key) and right (‘rh’ key) hemispheres. The right hemisphere is optional. If provided, rotations are derived from the rotations computed for points_lh by reflecting the rotation matrix across the Y-Z plane.
data (dict[str, ndarray] or ndarray) – Dictionary of data to randomize. Array of variables arranged in columns for each hemisphere.
unique (bool, optional) – Whether to enforce a one-to-one correspondence between original points and rotated ones. If true, the Hungarian algorithm is used. Default is False.
n_rep (int, optional) – Number of random rotations. Default is 100.
surface_algorithm ({'FreeSurfer', 'CIVET'}) – For ‘CIVET’, no flip is required to generate the spins for the right hemisphere. Only used when points_rh is not None. Default is ‘FreeSurfer’.
random_state (int or None, optional) – Random state. Default is None.

Returns:

rand_lh (ndarray, shape = (n_rep, n_lh, n_feat)) – Permutations of data in left hemisphere.
rand_rh (ndarray, shape = (n_rep, n_rh, n_feat)) – Permutations of data in right hemisphere. Only if right data and sphere are provided.