[ns] Help on gt-itm

[Sencun Zhu <szhu1@ise.gmu.edu>]

could anybody tell me how to use itm to generate a hierarchical topology,
I did it according to the instruction,the below is an example:

#.......
          hier 1 47
          4 0 0
          3 200 3 1
          5 20 3 0.4
          3 2 3 0.3
          3 1 3 0.2

but it does not work, from the geo_hier(...) function in function
Makegraph in file itm.c it returns NULL, since I do not understand how
this kernel function runs. I hope the mistake is from the specification
file, any hints will be highly appreciated!