Hello, so i'm GEMming it up right now. I have a square whose size follows the amplitude of a signal and i want it to change colour on the transients.

the [env] object streams the output , I multiply and divide to put it into a meaningful scale, but then i can't think of a way to create a single bang only when the number has changed by a significant amount (after the [int] stage) any ideas?

http://www.pdpatchrepo.info/hurleur/gem_mess.pd

there might be an external to do that...not sure...

anyway here's something i put together in vanilla pd. hopefully it will work ok.

http://www.pdpatchrepo.info/hurleur/significant-change.pd

Thanks very much hardoff, can you explain the theory behind the patch of yours?
they're all basic commands but it's mapped together in a perplexing way.

... Well it's definitely doing something! and is much closer to what I had in mind. thanks this is great.

But I can't work out what's going on

i added some notes, hope they help to clear things up...it was a bit hard to explain.

http://www.pdpatchrepo.info/hurleur/significant-change(notes).pd

arif
I think you can use [change]

[int]
|
[change]
|
[bang<

Ah the change object, that, i didn't even know existed. Great stuff audioripple, but if i had used that Hardoff would have had to supply the solution to my follow up question anyway (which is his patch)... The amplitude is always changing, so I need the object to change colour only on the 'peaks'

ok, if you only need peaks, you can use this

http://www.pdpatchrepo.info/hurleur/findmax.pd

brillaint simple solution, but Significant Change still wins here because it caches the troughs as well as the peaks.