'Get a coordinate slice'

def get_coord_slices(self, xmin, xmax, ymin, ymax, nx, ny):

    x = np.linspace(xmin, xmax, nx)
    y = np.linspace(ymin, ymax, ny)
    (Y, X) = np.meshgrid(y, x)
    pixel = np.array([X.ravel(), Y.ravel()]).transpose()
    world = self.transform(pixel)
    return (X, Y, [world[:, i].reshape(nx, ny).transpose() for i in range(self.wcs.wcs.naxis)])
