Thread: Venus Series City Navigator China NT CHS 2011.11

Originally Posted by syzygy

It's not clear to me if ISM.IDX contains any shifted data that needs to be corrected or not. Judging by its extension IDX, I guess it should contain indices for searching purpose only and needs no correction.

If you have an official Garmin China device, you certainly can choose to install the official map or the Venus (optionally with QSI and ISM) map. Just need to make sure the shift adding feature provided by the bin file is or is not activated respectively. For all other devices, Venus map (without QSI and ISM) is the only choice left for China NT map.

I just guess from the result plans and its names:
1. idx = index = properties , relationship and namespace alias
2. Any kind of alias must have a way to locate unique GPS record/mark. And vice versa.
3. Venus maps has unreliable distant-trip plan ---> such kind of coordination and alias seems less valid.
4. if the shifted GPS marks are used by aliases and their indexes, it might be impossible to offer a Venus version. In such a case precondition #1-2 ( #2 might be a false one) in this case might not be satisfied.-- e.g., for multi-connected points in several blocks , which are already orphan OR folded in Venus, their relationships and properties are already broken . Even their namespace aliases are consistent with corrected GPS marks, it will not work any more.

And for this reason and this result, inter-blocks {route} Mechanism is hard to rebuild in Venus.

Above is not based on any kind of research as syzygy has already done. I just tried to discuss this possibility in viewpoints of database and data structures --- could be nonsense as well.

Ander:
junction=crossing query
Intersection might be detailed address ( street, bld. number ) query. I have no such a device, try yourself.