# Circle waves

So i’ve seen square, triangle, and sine, but I was thinking is there such thing as a circle wave? I realized one half of a sine wave cycle is not a semi-circle, and I am wondering if there is a way to generate a “circle” wave? In a sense like a square wave, where one half of the circle goes on the positive, and then the other half goes to the negative voltage.

Circles have a problem because part of the wave goes backwards, from right to left. The timeline never goes backwards. It’s always now to the future, left to right.

Koz

You mean a semi-circle above the centre line, followed by a semi-circle below the centre line, followed by a semi-circle above the centre line… ?
Yes that is possible, but it does not sound particularly good
It’s very late here so I’ll have to come back to this tomorrow with a way to produce such a waveform.
cul8r.

This is what I mean

… it’s not possible to make them “exact” semi-circles because the start and end of the semi-circle should be vertical (rising instantaneously), but you can get very close.

Thats same for square waves correct?

Just seen your new post - that’s what I thought you meant Yes you can get very close to that, but it’s too late here for me to work out the details. I’ll leave this page open so that I don’t forget

Yes.

I’ve not finished my cup of tea yet, so here you go - select part of an audio track, open the Nyquist Prompt from the Effect menu, paste this code into the Nyquist Prompt text box and click OK.

``````(defun c-tone (hz g)
(let ((c-array (make-array 2048)))
(dotimes (i 2048)
(setq x (- 1 (/ i 1024.0)))
(setf (aref c-array i) (sqrt (- 1 (* x x)))))
(setf positive (snd-from-array 0 1024 c-array))
(setf negative (mult -1 positive))
(setf *c-table*
(list (seq positive negative) (hz-to-step 1.0) t))
(mult g (osc (hz-to-step (* 4.0 hz)) 1 *c-table*))))

(c-tone 440 0.8)
``````

I’ve moved this to “Audio Processing”.

Gale

Thanks so much steve, I really kinda like this wave, its not as harsh like a square wave, but it isn’t as pure as a sine wave, just in the goldylox

Koz recently pointed out to me that something similar can be achieved using the “leveller”

Which could be even nearer “goldylox”.