Intro to Grasshopper

I have been running myself through Grasshopper (a plug-in for Rhino) tutorials becoming comfortable with the interface and understanding how the Boolean logic works.  I have learned how to create an Boolean based  attractor.  It would change the radius of circles based on their distance from an "attractor" curve.  This was actually pretty similar to the logic I was using in my last generative diagram.  The original tutorial had two fixed radii for the circles in the grid.  Radius A was for circles from a certain proximity (variable) of the attractor line while Radius B was for all others.  I changed the tutorial to be closer to what I was doing manually before in my generative diagram.  Now there was still an A or B but A and B will change the radius by a different factor of the distance it is from the attractor line.  Here are the outputs with "proximity to line" set at 20, 45, 50, 55, and 60 respectively:

The progression of proximity goes from top to bottom.  I also worked with density of line weights from left to right.  The results yielded an unexpected spiral like effect.  I am unsure to what caused it.  I had expected the circle to just keep getting denser in the area of the curve.  The other points remain the same distance from the "attractor line" so unless they come into the "proximity area" they should keep outputting the same size.  However this is not the case.  The density of the diagrams shifts differently than expected.