commathe

I've been working on this all day and my brain is pretty fried. I have a *usable* but not exactly attractive solution right now. What I want to do is draw a waveform on an iWhatev using FantaStick, and then later layer a display over it.

I'm basically trying to split up chunks of a sample and read them chunk by chunk with a peek~ object and then take the maximum and minimum value from the whole chunk. I can't seem to get this to work out though. I'm not sure how to group all of the values that come out sample by sample and then evaluate them together. Maybe I haven't looked hard enough but there doesn't seem to be a zl object for this. Otherwise I'd just pack them into a list. The problem is that I'll only get the LAST value of the chunk right now. I want to get the maximum and minimum in every chunk. This might be a group of 3, or in a longer sample could be out of a group of 10,000 or more. I'd need to be able to clear the running total periodically too.

Alternatively, can anyone think of a better way to draw a waveform? I'm worried max/min might draw something that's pretty uneven and over exaggerated and might cause issues when trying to actually use the waveform display. Mean? Average? Suggestions there would be appreciated. Does anyone know how wave form display usually interpolates? Such as in the max~ buffer display? This will probably be useful later when I have to scale it to fit two or more waveforms on the screen at once. There's not a lot of space!

Here is what I have right now. You'll need FantaStick to see the output proper. (I'm having another issue where it seems that it's truncated at one end, like my screen resolution is actually 320x460 and not 320x480). I've tried to comment and colour it into oblivion. The purple bit is where my issue lies:

getting-the-maximumminimum-from-a-big-group-of-values

Update: I've been looking at trying to use jit.3m to get a max and a min out of a single plane of a matrix. What I don't understand at all though is how to resize a matrix automatically along only one dimension (x) and also fill it automatically with an uzi. I haven't looked at jitter once till today. It's as confusing as everything else was the first time!

While it may seem overwhelming for a matrix beginner, use jit.expr instead of filling it manually. It will make more sense.

I'm not sure why you are looking to make a matrix 1 dimension but if you wanted to you can just do jit.matrix 1 char 1 99999 (sorry don't have a calculator, whatever 320x240 is) and then jit.expr @expr norm[0] (or something like this, check the syntax in the jit.expr help manual).

Sorry I can't quite understand what you are up to in the rest of your post, I'm tired and haven't had coffee yet.

While it may seem overwhelming for a matrix beginner, use jit.expr instead of filling it manually.  It will make more sense.

Sorry I can't quite understand what you are up to in the rest of your post, I'm tired and haven't had coffee yet.


I think I wrote it out badly in the midst of my stress. I'll check out using jit.expr. What I'm trying to do is look at portions of a buffer~ and get the maximum and minimum peak from each portion. For example from sample 0 to sample 100, then from sample 100 to sample 200 etc. and then get what the maximum and minimum value from each section is. Then I use these max and minimum values to draw a waveform on an iPhone screen using fantastick

The logic behind a one dimensional matrix is that it's much easier to make it's dimensions (x) by 1 and then vary it, as opposed to having a big mess of zeroes in the cells I'm not using that might mess with my output.

Getting the maximum/minimum from a big group of values