Share 'Trouble with points'

Hello fairly new to grasshopper, and I have a quick question for you guys.  I'm trying to move all vector points away from the center of the circle say 1mm.  I tried pt(pointpolar) but i could only get the points to move in the x y or z, instead of a more offset move.  I would also like to alternate each point on the line so the first point moves out 1 mm and the next point moves in -1mm.  Any su…