[Paraview] Python calculator question

[Tim Gallagher]

Hi,

We're trying to compare two datasets using the Python calculator and the instructions on:

http://paraview.org/Wiki/index.php?title=ParaView/Users_Guide/Python_Calculator#Comparing_Multiple_Datasets

However, when we choose our datasets and apply the filter, it says it doesn't support vtkMultiblockDatasets, only vtkDatasets. The documentation at the end of the mentioned page seems to imply that it should work for multi-block and AMR datasets, except the global_max, global_min, and global_mean functions. 

Any ideas?

Tim