Function make_rand_affine

tests/test_utils.py:421–431

Create random affine transformation (with values == -1, 0 or 1).

(ndim: int = 3, random_state: np.random.RandomState | None = None)

def make_rand_affine(ndim: int = 3, random_state: np.random.RandomState | None = None):
    """Create random affine transformation (with values == -1, 0 or 1)."""
    rs = np.random.random.__self__ if random_state is None else random_state  # type: ignore

    vals = rs.choice([-1, 1], size=ndim)
    positions = rs.choice(range(ndim), size=ndim, replace=False)
    af = np.zeros([ndim + 1, ndim + 1])
    af[ndim, ndim] = 1
    for i, (v, p) in enumerate(zip(vals, positions)):
        af[i, p] = v
    return af


def get_arange_img(size, dtype=np.float32, offset=0):