def __getitem__(self, key): x0, x1, xstep, y0, y1, ystep = slice2gridspec(key) grid = linear_interpolate_grid( x0, x1, xstep, y0, y1, ystep, self.default_value, self.planes, self.triangulation.x, self.triangulation.y, self.triangulation.triangle_nodes, self.triangulation.triangle_neighbors) return grid