You say mark, what type of mark do you mean.
Draw a 'circle' at those points, or place a point ?
If circle for marker, what's the Diameter ?
If point, what type - pdmode 2, pdsize 10.0 ?
And, if polyline and it's 'closed', there will be no midpoint, but that
can be calculated with a bounding box. And if closed, endpoint = startpoint.
So, do you want (2) marks on top of another ?
It would be good to upload a sample, with before and after.
ECCAD
