Gardener ellipse with grasshopper and galapagos

Hi,

I'm trying to create the gardener ellipse with grasshopper and galapagos.( 2 distances from focus sum -major axis length=0 ----> Fitness=0)

ellipse.gif

I impose that the sum of the distance from a generic point from Focus is equal to major axis.

I post my algorithm.

I fixed the x coordinate (by item) and i reach the y coordinate (input for galapagos) that respect Fitness =0.

ellipsepoint.gh

Then I tried to create another algorithm that reach all y coordinate for all points toghether. But with that the algorithm doesn't run and I have different values from 0.

ellipse_allpoiints.gh

notZero.png

I can't understand why..

Can someone help me?

Thanks