Little help please: attempting to invert the concavity of osc~

At this point my poor brain can handle no more so need some help.

Was just thinking the other day it would be cool to change the concavity of osc~ so where it curves up (each pi/2, with 2pi=one wavelength) it curves in the opposite direction.

What I have so far is below and I have only got so far as using tangent which is wrong for what I had originally hoped.

Here is what I think it could/might/should look like:

What I Have learned:

Is one can derive pi/2 by taking the inverse of the input frequency as a wavelength and dividing by 4 (since osc~ really takes theta to be time).

And it seems Higher Minds will know a much cleaner way to accomplish this.

Thanks in advance.

Peace, good cheer, and music thru us all.

Sincerely,

Scott