bzsmooth command format help

Hi,

I'm trying to use this command in Draw and I can't work out the format.

I see the help info:
Draw:
> help bzsmooth
bzsmooth : bzsmooth cname tol degree option [fic]

and from GeomliteTest_ApproxCommands I can see that there are 3 methods/options: -GR, -PR and (unnamed? possibly -VA) method 3. Is there any information what these options do?

[fic] seems to be a file of the points to import: is there an example or format available?

Without the file ref the gui pick points with mouse works fine and creates a 3d curve

The file import option calls PointsByFile (also from GeomliteTest_ApproxCommands):
//=======================================================================
//function : PointsByFile
//=======================================================================
static void PointsByFile(Handle(AppDef_HArray1OfMultiPointConstraint)& MPC,
Handle(AppParCurves_HArray1OfConstraintCouple)& TABofCC,
std::ifstream& iFile,
Draw_Interpretor& di)

I get an exception when I try this:
Draw[3]> bzsmooth oc1 0 3 -PR iFile.txt 6 2d
An exception was caught 000002B022C70120 : OSD_Exception_ACCESS_VIOLATION: ACCESS VIOLATION at address 0x0000000000000010 during 'READ' operation
where the iFile.txt looks like this:
27.0 1.0
28.0 3.5
28.7 5.4
29.7 7.6
30.9 10.0
31.8 12.6

Any help or pointers greatly appreciated!

I'm using the 7.8.0 pre-compiled windows occt-vc143-64 version

Cheers,
David