On Tue, 18 Apr 2006, IOhannes m zmoelnig wrote:
[matrix~] (from zexy<2.0) will get a vector of output-signals O^ from a vector of input signals I^ via the following equation: O^'=I^'*A this is a bit weird since in the scientific community this equation is usually denoted as: O^=B*I^ (both equations are the same if B==A') however it does makes some sense (at least: it did for me :-)) in terms of the pd-patch (creation arguments of [matrix~] and how you connect cords to the inputs of the object) anyhow: [matrix~] is deprecated, don't use it! use [mtx_*~] instead, which follows the scientific convention...
Science and math are full of contradictory conventions. You prolly have encountered little-endian polynomials by now, as well as big-endian polynomials. Matrix rows are top-to-bottom, but plane geometry is bottom-to-top. Modular arithmetic usually starts at 0, but matrix indices start at one. Row numbers come before column numbers if you're dealing with matrices, but we write points as (x,y).
I've known profs that bitched at each other because one wanted to write y=Ax and the other wanted to write y=xA'.
The result is that I don't care. All I want is a system that is internally consistent so that I don't have to look up the manual to figure out the order of things.
Btw, in [matrix~], where's the inlet for modifying the matrix's values? is it leftmost or rightmost? what is it with [mtx_*~] ?
it had non-standard behaviour and there was NO help-patch at all....)
When there's no standard it's normal to be non-standard.
_ _ __ ___ _____ ________ _____________ _____________________ ... | Mathieu Bouchard - tél:+1.514.383.3801 - http://artengine.ca/matju | Freelance Digital Arts Engineer, Montréal QC Canada