[CM] Rearranging a sequence

[Landspeedrecord]

So you don't think I am crazy/stupid I suppose I should elaborate more.

Let's say a Seq has 10 midi notes in it.  Each note is merely an
instance of the class "midi".  Each note has slots for time, keynum,
duration, amp.  My view of the seq is a like a jar of marbles.  When
the seq is called by some function (list-objects or whatever), that
function then orders the marbles based on it's time slot.  Or
alternately, the ordering happens whenever something happens to any
time slot value in a seq, like when a new midi note is inserted at the
beginning of the seq.  Then all the marbles are rearranged and the seq
is resaved to be called upon later.

The point being that the ordering has to happen at some time based on
the time slot value and if so, then one should be able to rearrange
the time values.

Sorry for all the verbage, I just don't want anyone thinking that I am
trying to make time reorder.  That is impossible.  I am trying to make
the note's time values reorder which is a different thing.

Please let me know if I have this all wrong conceptually.

Thanks!




On 4/10/07, Landspeedrecord <landspeedrecord@gmail.com> wrote:
> Thanks Rick!  Using fold-objects in conjunction with cons would have
> taken me weeks to figure out so I appreciate your help.
>
> However, what I want to do is exactly what you are saying I shouldn't.
>  The only thing I want to shuflle/reorder is the midi time.  All the
> other midi information (keynum, duration, amp, chan) is supposed to
> stay together so that the notes remain the same but just come out in a
> different temporal order.  Why do I want to do this?  Because I am
> trying to manipulate midi files that correspond to .rex files (chopped
> up rhythms produced by propellerheads recycle). If I can rearrange the
> midi file I can come up with endless variations of the looped audio
> file.
>
> I am confused.  I thought the midi "time" value was just another
> slot/keyword value of the MIDI class (i.e. the same as keynum or
> duration).  I figured that it was only until the seq was put into the
> scheduler that the midi time became "cemented" in.  Do I have it all
> wrong?
>
> On 4/9/07, Rick Taube <taube@uiuc.edu> wrote:
> > you shouldnt "rearrange the time values" of the seq's objects -- the
> > purpose of a seq is maintain a time-ordered list of events!
> >
> > assuming you want to scramble keynumbers or something like that you
> > could do this
> >
> > ;; create a seq of midis
> >
> > (defparameter myseq
> >    (new seq :subobjects (loop for i to 100
> >                           collect (new midi :time i :keynum i))))
> >
> > ;; look at the first ten
> >
> > (list-objects myseq :end 10)
> >
> > 0. #i(midi time 0 keynum 0 duration 0.5 amplitude 64 channel 0)
> > 1. #i(midi time 1 keynum 1 duration 0.5 amplitude 64 channel 0)
> > 2. #i(midi time 2 keynum 2 duration 0.5 amplitude 64 channel 0)
> > 3. #i(midi time 3 keynum 3 duration 0.5 amplitude 64 channel 0)
> > 4. #i(midi time 4 keynum 4 duration 0.5 amplitude 64 channel 0)
> > 5. #i(midi time 5 keynum 5 duration 0.5 amplitude 64 channel 0)
> > 6. #i(midi time 6 keynum 6 duration 0.5 amplitude 64 channel 0)
> > 7. #i(midi time 7 keynum 7 duration 0.5 amplitude 64 channel 0)
> > 8. #i(midi time 8 keynum 8 duration 0.5 amplitude 64 channel 0)
> > 9. #i(midi time 9 keynum 9 duration 0.5 amplitude 64 channel 0)
> >
> > ;; gather the keynumbers
> >
> > (defparameter seqkeys
> >    (fold-objects #'cons myseq '() :slot 'keynum))
> >
> > ;; now shuffle the keynums and put them back
> >
> > (let ((mixedup (shuffle seqkeys)))
> >    (loop for m in (subobjects myseq)
> >       for k in mixedup
> >       do (sv m :keynum k))
> >    )
> >
> > ;; look at them again
> >
> > (list-objects myseq :end 10)
> >
> > 0. #i(midi time 0 keynum 60 duration 0.5 amplitude 64 channel 0)
> > 1. #i(midi time 1 keynum 68 duration 0.5 amplitude 64 channel 0)
> > 2. #i(midi time 2 keynum 15 duration 0.5 amplitude 64 channel 0)
> > 3. #i(midi time 3 keynum 51 duration 0.5 amplitude 64 channel 0)
> > 4. #i(midi time 4 keynum 29 duration 0.5 amplitude 64 channel 0)
> > 5. #i(midi time 5 keynum 52 duration 0.5 amplitude 64 channel 0)
> > 6. #i(midi time 6 keynum 35 duration 0.5 amplitude 64 channel 0)
> > 7. #i(midi time 7 keynum 74 duration 0.5 amplitude 64 channel 0)
> > 8. #i(midi time 8 keynum 25 duration 0.5 amplitude 64 channel 0)
> > 9. #i(midi time 9 keynum 16 duration 0.5 amplitude 64 channel 0)
> > CM>
> >
> >
> >
> >
> >
> >
> > On Apr 9, 2007, at 6:52 PM, Landspeedrecord wrote:
> >
> > > I having been trying to rearrange the time values of a MIDI file, i.e.
> > > rearrange the ordering of the notes while keeping all the other MIDI
> > > information intact.  I can load the MIDI into a seq object but from
> > > there I hit a brick wall.
> >
>