Only you can say whether putting two Circles of 10-unit diameter 11 units apart, and drawing the tangent Line between them, gives you a shape that is close enough for you to matching the waviness in your original image.  As you mentioned, maybe a Spline could make a more precise match.  But seriously -- how precisely does it need to match?  I assume the squiggly-wavy pointer is just a graphic convention for some relationship [sub-atomic particle movement or something?], not representative of an actual physical object, so what does it matter whether the precise shape of the waviness matches exactly?  And frankly, to me it looks like the end-most bulges in the original image are slightly smaller than the intermediate ones, which if true, you could construct if you really need that difference, but would not be possible with a shape-embedded linetype, which would need all bulges to be exactly the same.  So what does it represent, and how much does the exactness of the wavy shape really matter?

Well, this may not be any more precise about matching the wave shape, and seems like a lot of work compared to other approaches, and hugely more difficult if you need to adjust it.  But I would do it with Snap turned on and a series of regularly-spaced positions.  Here, Snap and Grid are both set to 1 drawing unit -- note how the cursor pops to only grid positions.  I pre-positioned Points [green] just to illustrate what I was up to, but they are not needed.  You will want to experiment with the arrangement for "close enough" precision.  This is in a SPLINE command.

Edited by Kent Cooper - 25.Apr.2024 at 20:02

The "good" thing to do when drawing a spline is adding start and end tangents.

Edited by philippe JOSEPH - 26.Apr.2024 at 13:16

About tangent of spline, see eventually : 

TEST SPLINE 01 Aa.dwg

Edited by philippe JOSEPH - 26.Apr.2024 at 16:18

philippe JOSEPH wrote: ... Any informations about start and end tangents ? I had previously posted a discussion about that with an AutoCAD file but got no answers.