scale of a curve

You need a gp_GTrsf to describe that "stretching" transformation.
We convert the curve to NURBS and transform its control points, but maybe there is a class which does it.

Mauro

//you need to define a vector for the X direction, (it could be facing any direction):

gp_Vector dir(1,0,0);

//define a center of scaling, used the origin here, but use the center of gravity of the object

gp_Pnt center(0,0,0)

//create a gp_Ax2 using the center point of scaling and the X vector

gp_Ax2 xdir(center, dir);

//create a transform using the 2axis system and the scaling amount x

gp_GTrsf x_aff;
x_aff.SetAffinity(xdir,x);

// apply transform to shape

BRepBuilderAPI_GTransform aBRepGTrsf(theobj, x_aff,Standard_False);

//get the result

aBRepGTrsf.Shape();