Re: MLS code for bounty?

[Butler]

Thanks for the reply Jordi. Details, then:

Again, I should mention up front that my math skills are pretty much 
non-existent so if I seem to know anything about the below that is just 
due to me trying hard to understand my problem and researching but does 
not indicate any level of true understanding. I am weird in that while 
my math skills don't exist, I have some understanding of programming.

I am a sound engineer attempting to create some flat panel sound 
diffusers (based on ideas from a paper given at an Audio Engineering 
Society convention in NYC some years ago-historically, diffusion panels 
must have great depth to work, often causing an architectural dilemma 
since who wants to give up several feet of space next to a wall in their 
control room. The idea behind this new-ish design is essentially to 
substitute absorption for depth) for use in my recording studio. This 
involves creating a (acoustically) reflective mask with a pseudo-random 
arrangement of holes to cover an absorptive panel. Grid cell dimensions 
are immaterial to this process but in this initial case will be 1" squares.

My understanding is that I need to generate a binary m-sequence a/k/a 
maximum length sequence:

http://en.wikipedia.org/wiki/Maximum_length_sequence

... to be mapped onto a specific grid (in this initial case 49x30) via 
the Chinese Remainder Theorem.

Not having much of a budget for MatLab, it seems like Octave, as an open 
source solution, would be ideal. What I would like is code to generate 
an m-sequence and next a grid, based on the grid dimensions. So grid 
dimensions are input first, then an m-sequence that can be mapped to 
them generated, then that m-sequence mapped. It's my understanding that 
the top/side dimensions of the grid must be coprime for this to work, 
which (yes, this is the er, depth of my ignorance) I believe 49x30 would be.

There may also be some considerations vis a vis a convenient output 
format, but first-thoughts? Does this sound possible? Difficult/involved 
(possibly beyond my means in terms of $$)? I'm hoping maybe this could 
result in some new function(s) for Octave as a bonus to the community if 
not all functionality needed for this exists.

Best,
CDB






Jordi Gutiérrez Hermoso wrote:
> 2008/11/7 Butler <address@hidden>:
>   
> > So this is not a question re: help with octave, more a
> > question asking whether there is a place where I could offer a bounty
> > for working code? I could post details but don't want to start an
> > off-topic discussion...
> >     
>
> This is probably ontopic in this mailing list, but you could also post
> the details of your problem to the Octave maintainers list at
>
>      address@hidden
>
> I'm eager to hear the details.
>
> - Jordi G. H.
>   


--
Chris D. Butler

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