[PD] [pmpd] - meaning of messages

cyrille cyrille.henry at la-kitchen.fr
Mon Feb 28 17:44:32 CET 2005

hello frank,

thanks for trying this object.

Frank Barknecht wrote:
> Hi,
> I have a couple of questions regarding the [pmpd] object. It is not
> quite clear to me, what the messages to this object mean exactly.
> Actually I'm very confused about them.

i'm also very confused.
the aim of pmpd version 0.06 was only to make a prototype and think 
about it.

the thing that is clear for me now is that is not really usefull to have 
pmpd and pmpd~ object with exactly the same option (like it is now).

i think in the future i'll split pmpd~ on diferents object (modal~, 
scan~ and pmpd~)

> As I see it, there are basically four messages possible to create the
> dynamic system: mass, link, in, out. 
> All of these take IDs as arguments. I don't understand the meaning of
> those IDs. For example to create a mass, one uses messages like: 
> mass ID MASS X
> MASS and X are easy, but what is this "ID" used for? 

id is an identifiant for the masses. (and for the link)

with old pmpd version : when you create a mass object, the parametter 
are a name, masse and position : the identifiant (id) is here to replace 
the name of the mass.

you can set the position of a mass at any time by sending a message 
addressing to the id.
this allow you to set position of 1 or more mass in the same time 
regarding to the stucture...

id is not very really usefull yet.
i would like to have a string as id, but a float was faster to code for 
this prototype.

> "link" also takes IDs as argument, but it seems to ignore the ID given
> to a mass on creation, instead it seems to use its own IDs and it has
> an ID itself:

in fact it's :
link LINK-ID MASS1-creation_number MASS2-creation_number  K D

creation_number is 0 for the 1st mass, 1 for the next etc...

2 mass can have the same id (mabee that will change).
so link use the creation order of the mass.

i know it's not a very good solution, and i'll be very happy if you have 

the performances are better this way than with the old way, but i'm not 
satisfied with usability...

> Where do I get the mass IDs from? In my experiments, it seems just
> have to keep track of them myself, and they have nothing to do with
> the ID I gave to a mass earlier. Or do I get it wrong? 
your right.

> Outlet creation (and inlet creation respectively): As I understand it,
> the format is: 
> AMPLITUDE seems to be a scaling factor. 
yep, scale is a better word.
(it's a problem with my bad english)

>OUT-ID I don't understand at
> all: what use does it have?
no one yet.
but if you would change the scale factor, then you have to send a 
message to this specific "out" object. id is the way to address this "out"

if you are familiar with modal synthesis, you'll understand the way is 
is now.

> Am I right to assume that OUTLET is
> numbered from 0 to max-outlet-number, where max-outlet-number is the
> second argument of pmpd minus one?
yes : [pmpd 3 4] will create an object with 3 inlet and 4 outlet.
so you can create any number of "out" you wish, but they have to be 
connected to the outlet 0 to 3. (4 outlet)

> And then MASS-ID: Does it start
> from 0 as well? Or from 1? Where do I get this ID from? 
you have to choose the id you wish (i think negative id is only for mass 
that should not move (fixed)).

>In my
> experiments, it seems to have to be the MASS-ID I used when creating
> the "link"s. 
> Sorry for my confusion... 

well, there is no good documentation, so it's my fault.

i did not make anythig new since 0.06, but new developement should be 
done befor this summer. so pmpd and pmpd~ will change, and i'm not sure 
compatibility will be a priority, so use this 2 object at your own risk.
(sorry, i'm not happy with the way they are now).


> Ciao

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