Sinusoidal point along the z-axis maintaining circular shape

[s138617]

hello,
basic question here: I tried several methods but none seem working.
I am trying to move points of a circle in z axis to create a regular closed sine wave in a circle shape, but after connecting a interpolate node (toggle true to periodic in interpolate node) curve will close with a straight line or in a
sinewave001.gh (21.8 KB)
irregular way, not following the sinusoidal shape.

thanks for your time

[inno]

Range creates n+1 values:

you can right click on Range N input and write as Expression x-1 to get 9 steps instead of 10, which will result in 10 points

[Joseph_Oster]

sinewave_circle_2024Feb7a.gh (9.5 KB)

P.S. Lofting the circle and sine wave works well.

sinewave_circle_2024Feb7b.gh (9.6 KB)
Actually, not so well if you look closely…

P.P.S. This fixes the lofts except alternate surface normals are flipped.

sinewave_circle_2024Feb7c.gh (16.1 KB)

So flip alternate surfaces… GH is so hard!

sinewave_circle_2024Feb7d.gh (18.5 KB)

[s138617]

@Joseph_Oster

Lofting the circle and sine wave works well.

This is a brilliant solution. Thank you.