Question about the pamameters of Arcto in sverchok's "Profile Parametric Node" &lt;2v rx,ry&gt; &lt;float rot&gt; &lt;int flag1&gt; &lt;int flag2&gt; &lt;2v x,y&gt; &lt;int num_verts&gt; [z]


As the syntax above shows，ArcTo has 3 parameters（ float rot, int flag1 and int flag2 ） between the radius vector and the coordinate vecter.  
I've found that the third(int flag2) can be used to set the direction of the arc(CW or CCW),but I can't find out what the other 2 parameters( float rot and int flag1 ) stand for and can be used to do.  
It will be kind of you to tell me the answer, and thanks in advance.^_^
This node was intended to closely resemble the SVG style of specifying paths, and you should really look at what SVG specs say about ArcTo 

;; straight from the svg specs
(rx ry x-axis-rotation large-arc-flag sweep-flag x y)


For a deeper description see this github issue tracker post:
https://github.com/nortikin/sverchok/issues/350#issuecomment-51353886