Hi, everyone! I met trouble when I used YT-fliter function At first, I have tried exclude_ function, however, it said that there is no such an attribute. The version of my YT is 3.5.0, I donnot know if it is because of the old version. Here is the error info: ------------------------------------------------------------------------------------------------------------------------------- File "vorfield.py", line 85, in <module> vort_ds=ds.exclude_inside(('boxlib','vort_z'),-1e3,1e3) P000 yt : [ERROR ] 2022-01-26 17:34:53,155 AttributeError: 'BoxlibDataset' object has no attribute 'exclude_inside' application called MPI_Abort(MPI_COMM_WORLD, 1) - process 0 -------------------------------------------------------------------------------------------------------------------------------- Then I tried cut_region function, however, it said that some argument is lost and I donnot know why. Here is the error info: --------------------------------------------------------------------------------------------------------------------------------------------- File "vorfield.py", line 82, in <module> vort_ds = ds.cut_region(['(obj["boxlib", "vort_z"] > 1e3)']) P000 yt : [ERROR ] 2022-01-26 17:07:37,086 TypeError: __init__() missing 1 required positional argument: 'conditionals' application called MPI_Abort(MPI_COMM_WORLD, 1) - process 0 ---------------------------------------------------------------------------------------------------------------------------------------------- I will be appreciate if anybody can help me! Thank all! He Yifeng