Add default value to docstrings
Add default value to docstrings

Signed-off-by: Antonio Ossa <1ecf3d2f96b6e61cf9b68f0fc294cab57dc5d597@uc.cl>

FrancoisRheaultUS/dipy,nilgoyyou/dipy,FrancoisRheaultUS/dipy,nilgoyyou/dipy