[PD] Need Help Understanding pack

[Theron Trowbridge]

Thanks!  I used [pipe] because I had an obvious timing problem and that was
an explicit delay object.  Didn't occur to me that [trigger] could control
the timing as well.  It's use wasn't obvious to me from what I had read
about it.

I will make the adjustments you suggest and see where I get.  I expect I
will have more questions.


Thanks again,

-Theron
^

On Fri, Feb 4, 2011 at 5:17 AM, Matt Barber <brbrofsvl at gmail.com> wrote:

> Hello,
>
> Before you go any further in Pd, you should check out the [trigger]
> object. It's the single most important object in Pd, in my opinion -
> it will help you get the timing right in these kinds of situations.
> Trigger forces hot-cold things to happen in the correct order
> explicitly -- without it you have to rely on the order in which you
> made the connections, which you can't SEE in the patch.
>
> You should use [trigger] instead of the [pipe 0] construction you have
> as well, the number box should most likely be a message with a zero in
> it (to hardwire it to zero), and you should probably be sending it to
> the cold inlet of the [int] (so that it just sets the [int] state
> rather than passing the zero through once when you set it and then
> once again on the first bang of the [until]).
>
> But again, master the use of [trigger] before you go any further --
> multiple lines coming from an object should make you feel
> uncomfortable until you're sure you're doing it correctly.
>
> I hope this helps.
>
> MB
>
>
> >
> > I've looked over the help patches, the FLOSS manual, and at a number of
> > examples, but I'm clearly missing something.
> >
> > I'm trying to build a proof-of-concept state table for a grid sequencer.
>  I
> > figured out to use an array to store my states, and I can write to and
> read
> > from the table, except when I'm trying to use pack.
> >
> > The reason for pack is to get the column, row, and state of each button
> in a
> > range of the state table (will be a single column in my end use, but I'm
> > doing the whole thing for now).
> >
> > Attached is a patch with a 2x2 grid set up and you can click on them and
> set
> > the state table.  That works.  It's the lookup part that doesn't.  I'm
> > stepping through the entire state table, deriving the column and row from
> > the index and looking up the value of that index.  This all works until I
> > send those three pieces of information to a pack object, it re-arranges
> > things in inconsistent manner.  Clearly there's either a timing thing or
> I'm
> > not understanding the data flow of what I'm doing.  Or maybe I'm just not
> > getting the point of pack.
> >
> > I'm pretty new to this and every step is a struggle, so any suggestions
> are
> > welcome.  But if there are any tips or pointers on why pack is not
> working
> > the way I think it should - or what I should be using to accomplish what
> I'm
> > trying to do - I would appreciate it.
> >
> >
> >
> > Long-winded description of how the attached patch is behaving:
> >
> > Buttons are arranged in column, row order.  I'm just storing 0/1 values
> in
> > the state_table array.  If I click on the first and last buttons, my
> array
> > is then 1 0 0 1.  So state_table[i] gets me the off/on value for the
> button.
> >  i div 2 gets me the column number and i mod 2 gets me the row number.
> >
> > If I just print these three outputs I get everything out in the order I
> > expect:
> >
> > column: 0
> > row: 0
> > state: 1
> > column: 0
> > row: 1
> > state: 0
> > column: 1
> > row: 0
> > state: 0
> > column: 1
> > row: 1
> > state: 1
> >
> > If I send the three values into a pack object and print the output of
> that,
> > I get:
> >
> > pack: 0 1 0
> > pack: 0 0 1
> > pack: 1 1 0
> > pack: 1 0 0
> >
> > I would expect this:
> >
> > pack: 0 0 1
> > pack: 0 1 0
> > pack: 1 0 0
> > pack: 1 1 1
> >
> > So things are coming in the wrong order overall, and the state values are
> > wrong.
> >
> >
> > Thanks,
> >
> > -Theron
>
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