def _deflection_kernel(self, x_grid, y_grid):
        """

        :param numPix:
        :param deltaPix:
        :return:
        """
        x_mean = np.mean(x_grid)
        y_mean = np.mean(y_grid)
        r2 = (x_grid - x_mean)**2 + (y_grid - y_mean)**2
        l0 = np.where(r2 == 0)

        kernel_x = util.array2image(x_grid / r2)
        kernel_y = util.array2image(y_grid / r2)
        kernel_x[l0] = 0
        kernel_y[l0] = 0
        return kernel_x, kernel_y
def _deflection_kernel ( self , x_grid , y_grid ) : x_mean = np . mean ( x_grid ) y_mean = np . mean ( y_grid ) r2 = ( x_grid - x_mean ) ** 2 + ( y_grid - y_mean ) ** 2 l0 = np . where ( r2 == 0 ) kernel_x = util . array2image ( x_grid / r2 ) kernel_y = util . array2image ( y_grid / r2 ) kernel_x [ l0 ] = 0 kernel_y [ l0 ] = 0 return kernel_x , kernel_y
:param numPix:
        :param deltaPix:
        :return: