[PD] Need Help Understanding pack

[Theron Trowbridge]

That worked very nicely.  I had to change the until input to 4 to get it to
do the right number of iterations, since the input didn't also kick off the
loop, but that's fine.

I'm not sure I understand exactly what was going on before, but I now have a
[trigger] object that does the [tabread] first, and then the mod/div math.
 So I understand why it works now.  Just not exactly why it didn't before :)

Now...  I have another [pipe 0] object in the button_handler sub-patch which
delays a message while a [expr] object does its thing.  Replacing it with a
[trigger] doesn't work.  But it's not coordinated with the other outputs of
the [unpack] object.

Is there an object like [trigger] that has multiple inputs and lets you
control the timing of the outputs?  [pipe] can take multiple inputs but
doesn't have the same right-to-left coordinated output that [trigger] does.

The FLOSS manual says that the order you hook things up in part determines
the order they do things.  But I can't make that make a difference.


Thanks,

-Theron
^

On Fri, Feb 4, 2011 at 12:50 PM, Theron Trowbridge <
theron.trowbridge at gmail.com> wrote:

> 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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