John Omotani

> test-squash -- is this going to be replaced by xBOUT? The functionality might eventually move into xBOUT (although last I heard there were still performance issues to resolve), but...

Maybe have an `ASSERT2` that the meshes of all fields are the same? I'd think that would be enough...

> Perhaps it would also be useful to have a link to some papers on particular models (e.g. STORM), or links to online manuals or repositories? I'd vote for links...

Scattered thoughts: * I'd agree with a re-write. I think a new (or at least) extended API with explicit reads and writes would be useful. * I wrote the HDF5...

We might need to be a bit careful about exactly when some quantities are written. For example, in STORM we normalise the metric components in the `PhysicsModel::init()` method, so writing...

> A separate thought, but one I want to write down somewhere -- we have a time dimension t which is timestep index, and a separate variable t_array which is...

> That's the dimension IDs, rather than the dimensions themselves. It turns out if you just define a dimension like we currently do, netCDF basically just makes an empty dataset....

> Thinking a little bit more about keeping track of the last time index for each variable -- instead of needing to call dump.extend_dimension("t") at the start of each output...

> Ah yes, I guess a flat-merge would be needed at the moment. Eventually it would be nice to have each PhysicsModel output in a tree, but XArray doeson't handle...

`shiftinput` is only useful (I think) for people moving from v3 to v5, although I guess there might be some people from LLNL or Japan who want to do that....