def function(self, x, y, image=None, amp=1, center_x=0, center_y=0, phi_G=0, scale=1):
        """

        :param x: x-coordinate to evaluate surface brightness
        :param y: y-coordinate to evaluate surface brightness
        :param image: 2d numpy array (image) to be used to interpolate
        :param amp: amplitude of surface brightness scaling in respect of original image
        :param center_x: center of interpolated image
        :param center_y: center of interpolated image
        :param phi_G: rotation angle of simulated image in respect to input gird
        :param scale: pixel scale (in angular units) of the simulated image
        :return:
        """
        #self._check_interp(grid_interp_x, grid_interp_y, f_, f_x, f_y, f_xx, f_yy, f_xy)
        n = len(np.atleast_1d(x))
        x_, y_ = self.coord2image_pixel(x, y, center_x, center_y, phi_G, scale)
        if n <= 1 and np.shape(x) == ():
            f_out = self.image_interp(x_, y_, image)
            return f_out[0][0]
        else:
            f_out = np.zeros(n)
            for i in range(n):
                f_out[i] = self.image_interp(x_[i], y_[i], image)
        return f_out * amp
def function ( self , x , y , image = None , amp = 1 , center_x = 0 , center_y = 0 , phi_G = 0 , scale = 1 ) : n = len ( np . atleast_1d ( x ) ) x_ , y_ = self . coord2image_pixel ( x , y , center_x , center_y , phi_G , scale ) if n <= 1 and np . shape ( x ) == ( ) : f_out = self . image_interp ( x_ , y_ , image ) return f_out [ 0 ] [ 0 ] else : f_out = np . zeros ( n ) for i in range ( n ) : f_out [ i ] = self . image_interp ( x_ [ i ] , y_ [ i ] , image ) return f_out * amp
:param x: x-coordinate to evaluate surface brightness
        :param y: y-coordinate to evaluate surface brightness
        :param image: 2d numpy array (image) to be used to interpolate
        :param amp: amplitude of surface brightness scaling in respect of original image
        :param center_x: center of interpolated image
        :param center_y: center of interpolated image
        :param phi_G: rotation angle of simulated image in respect to input gird
        :param scale: pixel scale (in angular units) of the simulated image
        :return: