grid.py 文件源码

def make_corners(self):

        x = self.x_t
        y = self.y_t

        dx_half = self.dx / 2.0
        dy_half = self.dy / 2.0

        # Set grid corners, we do these one corner at a time. Start at the 
        # bottom left and go anti-clockwise. This is the SCRIP convention.
        clon = np.empty((self.num_lat_points, self.num_lon_points, 4))
        clon[:] = np.NAN
        clon[:,:,0] = x - dx_half
        clon[:,:,1] = x + dx_half
        clon[:,:,2] = x + dx_half
        clon[:,:,3] = x - dx_half
        assert(not np.isnan(np.sum(clon)))

        clat = np.empty((self.num_lat_points, self.num_lon_points, 4))
        clat[:] = np.NAN
        clat[:,:,0] = y - dy_half
        clat[:,:,1] = y - dy_half
        clat[:,:,2] = y + dy_half
        clat[:,:,3] = y + dy_half
        assert(not np.isnan(np.sum(clat)))

        # The bottom latitude band should always be Southern extent.
        assert(np.all(clat[0, :, 0] == np.min(y) - dy_half))
        assert(np.all(clat[0, :, 1] == np.min(y) - dy_half))

        # The top latitude band should always be Northern extent.
        assert(np.all(clat[-1, :, 2] == np.max(y) + dy_half))
        assert(np.all(clat[-1, :, 3] == np.max(y) + dy_half))

        self.clon_t = clon
        self.clat_t = clat