APPLY

The APPLY framework provides a way to apply an operation on Geo Time Series™ grouped by equivalence classes. It is somehow similar to the REDUCE framework in the sense that everything you can do with REDUCE can be done with APPLY, but APPLY is more flexible and goes way beyond what REDUCE can do. The flexibility of APPLY comes with a greater complexity and thus both frameworks exist.

APPLY operates on multiple lists of Geo Time Series™, L1 ... Ln. The first phase of APPLY will partition each of those lists in equivalence classes by inspecting the values of the specified labels. If one of the lists is a singleton (i.e. contains a single Geo Time Series™), then it will be included in all equivalence classes, regardless of the values of its labels. If you wish to override this behaviour, simply duplicate the GTS in the list so it is no longer a singleton.

The second phase of APPLY will execute the operation for each equivalence class. The execution will apply the operation to n parameters, tick by tick, where the ith parameter is a list of lists of timestamp, latitude, longitude, elevation and value, one for each GTS from the list Li which is in the current equivalence class, in the order in which they appear in Li. The ticks scanned belong to the set of ticks of all Geo Time Series™ in the equivalence class.

The number of supported parameters depends on the selected operation, please refer to the documentation of each operation for the details.