[dbelford]

The Heyser spiral or Heyser corkscrew seems to be a common name for this type of plot. https://www.google.com/search?q=heyser+spiral

And it connects circles, e/euler's formula, and sin/cos is a visually grokkable way.

[zuminator]

Ah, well that's fair! In any case though "spiral" is a pretty general term; I'm really just trying to get a sense of the shape the op was referring to, assumedly not something like an Archimedean spiral. Thank you for that idenfication.