Hello, I made a figure, control points are completely symmetric, at points identical weight (except the lowermost), but the point highlighted in green color incorrectly influences a curve. At her as though other weight. I reflected vertical - as a result of the 2nd different result.
Hi Modeler - please post the file.
-Pascal
Hi Pascal, attached.
the file you posted does not resemble the image you show, nevertheless its probably a similar issue here and you can see that they are not really symmetric.
I hurried yesterday and haven’t kept contents of the top image - today have more or less repeated result.
The problem isn’t solved! If I do exact symmetry - the problem remains.
your points have not the same distances to the center as shown above, so they cant be symmetric.
if you distribute your points equally as shown below, your resulting curve gets 100% symmetric.
if out of any reason you managed to accidentally alter the weight of a Control Point you can use Weight
and click on the point or vice versa and set it to 1. or you just select all points and set to 1 
but in your case you simply did not draw an accurate curve even if you might have believed so.
I tried, but a curve all the same not symmetric (the most top image). Distances between points identical.
you tried how? describe how you create the curve or post an example where you have the points equally from the center and it still is not symmetric.
again the example you posted has the CPs NOT equally, which leads naturally to a non symmetric curve.
There points aren’t symmetric (hurried) and what difference if the curve all the same not is symmetric.
Now I can’t, I will send the file somewhere in 2-3 hours)
Here:
1.3dm (31.5 KB)
your CP are indeed symmetric and not weighted except the lower cp which should not effect the symmetry.
in this case the problem lays in the Edit Points which are not symmetric. i mirrored the left side seen as orange points on the right side they are off, also the yellow dots indicated here are actually 2 so the edit points are out of bounce there either. to quickly fix this you can use MakeUniform, i think that can happen when you delete points from an existing curve and also had that happening, its also interesting that the CP´s can be symmetric, while the edit points are not. maybe @pascal can explain why this is possible at all.
I have now and so tried and so - the curve is anyway not symmetric.
Having executed a curve on control points of this wrong curve - as a result a symmetric curve, everything is excellent. However I would like to know what the problem consists in?
did you try MakeUniform as i suggested?
this is natural, since they are symmetric. as i wrote they are ok but your EditPoints are off. Edit Points you can activate with EditPtOn in case you never used them. they are not the same as CPs.
i believe a curve can be, or is defined through 3 different points, Control Points, Edit Points and Knots. if you use the command InsertKnot you see that they are not equal in your curve. Knots cant be modified other than inserted or deleted. they can only be displayed by the command i just suggested and in CurvatureGraph when the density is set to 0.
i once asked pascal why they cant be directly handled and i am also still waiting for an answer there 
The form doesn’t remain 
you are kidding? what do you mean it does not remain? 
Wrong.
The form is not saved.
Hi all - I guess you’d want to start and end the curve on the axis of symmetry.
-Pascal
I think yes, in it as though a problem…
i tried that, but it does not seem to help,
Hm - dunno - looks clean here…
-Pascal
