Cycling 74 » Topic: scaling back to linear ?

scaling back to linear ?

Phijel — Sat, 04 Jun 2011 07:10:53 +0000

Hello maxers,

does anybody know if there’s a way to “invert” an exp scaling so that it goes back to linear like in the following example.

thanks

– Pasted Max Patch, click to expand. –

Re: scaling back to linear ?

n00b_meister — Sat, 04 Jun 2011 09:55:35 +0000

nothing useful here?

http://cycling74.com/forums/topic.php?id=33649

Brendan

Re: scaling back to linear ?

mr_mapes — Sat, 04 Jun 2011 10:03:11 +0000

If the first lin->exp scaling is in the form x^y and you know the value used for y then you can reverse it by using x^(1/y) e.g. x^2 -> x^0.5

Re: scaling back to linear ?

Phijel — Sat, 04 Jun 2011 20:19:53 +0000

thanks, I’ll look into that, missed that thread…

Any idea tho on how the exp base value used as the fifth arg in scale would translate into an expr using pow ? my maths are far away ;-)

Re: scaling back to linear ?

mr_mapes — Sat, 04 Jun 2011 22:08:09 +0000

I checked your patch earlier and used my suggestion of taking the reciprocal of the exponent as the new exponent in a reverse conversion, and I got a straight line….

So I think if you were using [expr pow] it translates to how the curve would behave if [scale] were first converting it’s input to 0->1, raising the result to a power, then scaling/offsetting as required by [scale]‘s output behaviour. If that makes sense….