reverse waveshaping ?

Jan 22, 2014 at 10:17am

reverse waveshaping ?

Hello, I can’t find out how to find the function (waveshape ?) to transform a sine to another given shape like in the picture enclosed.

How to ?
Thx.

Attachments:
  1. Capture-d’écran-2014-01-22-à-19.51.16
  2. Capture-d’écran-2014-01-22-à-19.13.51
#278877
Jan 22, 2014 at 5:38pm

Your pics didn’t post.

#278907
Jan 23, 2014 at 2:39am

strange. I can see it here.
here it is once again :

Attachments:
  1. waveshape
#278934
Jan 23, 2014 at 6:12am

Finding a function to perform a specific mapping is an extremely difficult mathematical problem. There are lots of mappings that are quite easy to do (look up, for instance, Chebychev functions). But there are an infinite number of possible functions (aleph-one infinity, I think), that leaves plenty of mappings that aren’t so easy.

If you’ve got the data that generated your images, you could just poke~ the numbers into a waveform and use that for your mapping. But presumably life isn’t that convenient for what you want to do. You could approximate by drawing into a table object. That won’t be super accurate, but might be, as they say, good enough for jazz.

#278946
Jan 23, 2014 at 8:38am

Thx a lot.
I did the poke~ option with ramps from -1.to 1. & 1.to-1. then separate into 2 [lookup~], one for ascending and one for descending ramp. It’s not really accurate but ok for now…

I’ll have a look at chebychev asap.

I tried an IR option too without success because it’s not linear I suppose…

Anyway, thx for your answer.

#278958

You must be logged in to reply to this topic.