'logit transform (base 10), masked or clipped'

def transform_non_affine(self, a):

    with np.errstate(invalid=u'ignore'):
        a = np.select([(a <= 0), (a >= 1)], [self._fill_value, (1 - self._fill_value)], a)
    return np.log10((a / (1 - a)))
