Hi, I've been working on setting up yt code to interpolate from an AMR dataset to a spherical grid of points. Thanks to help from Jeff, I've used a covering grid to extract the data and then TrilinearFieldInterpolator to derive the values on the grid of points. The problem is that the covering grid allocates the entire data array on the maximum level ~4500^3, which doesn't fit into the memory on the Nersc Davinci machine (72 gb max). I really only need the cells adaject to points in the output grid, which is < 150^3. Is there a more efficient way of using covering_grid or extracting the AMR data that doesn't involve first interpolating the entire region to the maximum level? (The code definitely works for smaller grids/ lower max levels, but I really need to get at the high resolution AMR data). Thanks for your help! Stella