Hi @ChrisBarker-NOAA, This puzzled me for a bit, until I remembered that in the CF data model, DSGs are _not_ special. This is because what looks like a discrete axis in the encoding of a DSG is a really just a form of lossless packing for an orthogonal multidimensional array (with the data and coordinate arrays padded with missing data if required). This is indeed different to the UGRID mesh, as you rightly picked up on.
So bringing DSG's into this was misleading - sorry! The [all that the CF data model says about DSGs](https://urldefense.us/v3/__https://cfconventions.org/cf-conventions/cf-conventions.html*_domain_axis_construct_and_the_data_array__;Iw!!G2kpM7uM-TzIFchu!kpIRMVftXZrAcR1WIvvNZ6ctbN1jxRTEXLA68dt7V_fuRrMa6_J0r1EyT1N_goBO3Cqr0opq5P4$ ) is: _When a collection of discrete sampling geometry (DSG) features has been combined in a data variable using the incomplete orthogonal or ragged representations to save space, the axis size has to be inferred, but this is an aspect of unpacking the data, rather than its conceptual description. In practice, the unpacked data array may be dominated by missing values (as could occur, for example, if all features in a collection of time series had no common time coordinates), in which case it may be preferable to view the collection as if each DSG feature were a separate variable, each one corresponding to a different field construct._ In my other examples (such as data stored on ocean basins) there is no assumption of (spatial) continuity, so I reckon that the CF data model discrete axis does apply to the UGRID case, after all. Thanks, David -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: https://urldefense.us/v3/__https://github.com/cf-convention/cf-conventions/issues/153*issuecomment-889701172__;Iw!!G2kpM7uM-TzIFchu!kpIRMVftXZrAcR1WIvvNZ6ctbN1jxRTEXLA68dt7V_fuRrMa6_J0r1EyT1N_goBO3Cqr1s8_kIw$ This list forwards relevant notifications from Github. It is distinct from [email protected], although if you do nothing, a subscription to the UCAR list will result in a subscription to this list. To unsubscribe from this list only, send a message to [email protected].
