Network creation

Networks can be generated from 3 three different formats. From version 1.05 of RW Net also supports records marked for deletion and objects of other types than (poly)lines in these. However this has made it neccessary to describe how each format is dealt with, what differencies there are and what to look out for.

The basic structure in the network files is a one-to-one relationship, where the first link in the network is related to the first record in your TAB/SHP file or whatever format you use. This is used in functions like IsoCostSave and RouteSave, but also when you query the individual part of a route with function RouteLink. If this doesn't match, you will get very strange results. The same would happen if the original TAB/SHP is sorted after the network has been generated. Then the one-to-one relationship would also be broken and you would have to recreate your network.

Even though both deleted records and other kind of objects are supported, you should try to avoid them as the network files get unnecessarily big.


MIF format

The MIF format doesn't support records marked for deletion, so the only issue here is records without graphical objects ("none") and records with other kind of objects (points, regions etc). These are fully supported.

Your only problem would be if the MIF file is created from a datasource with records marked for deletion, which hasn't been packed. This you should do before exporting to MIF format.


TAB format

The TAB format supports deleted records, objects of different types and records without objects. These are all handled without any problem. The only problem to be aware of is records marked for deletion, when creating the attribute file. Here you should make sure, that a record for the deleted records are created as well. In MapInfo this can be done by stepping through all records.


SHP format

Since the SHP format doesn't support neither records marked for deletion nor objects of different types within the same SHP file, there isn't any problem here at all.