def slit_select(self, ra, dec, length, width, center_ra=0, center_dec=0, angle=0):
        """

        :param ra:
        :param dec:
        :param R:
        :param d:
        :param center_ra:
        :param center_dec:
        :param angle:
        :return: bool
        """
        ra_ = ra - center_ra
        dec_ = dec - center_dec
        x = np.cos(angle)*ra_ + np.sin(angle)*dec_
        y = - np.sin(angle)*ra_ + np.cos(angle)*dec_

        if abs(x) < length/2. and abs(y) < width/2.:
            return True
        else:
            return False
def slit_select ( self , ra , dec , length , width , center_ra = 0 , center_dec = 0 , angle = 0 ) : ra_ = ra - center_ra dec_ = dec - center_dec x = np . cos ( angle ) * ra_ + np . sin ( angle ) * dec_ y = - np . sin ( angle ) * ra_ + np . cos ( angle ) * dec_ if abs ( x ) < length / 2. and abs ( y ) < width / 2. : return True else : return False
:param ra:
        :param dec:
        :param R:
        :param d:
        :param center_ra:
        :param center_dec:
        :param angle:
        :return: bool