[PD] array quantile problem

[cyrille henry]

hello,

thanks for your code,
I did not try the external.

in attachment, an other version : it need few externals and have no weight, but it's faster and is not limited to 5 points.


Cyrille
  

Le 24/12/2016 à 17:07, Charles Z Henry a écrit :
> An audio rate weighted median filter is possible to do with fexpr~ but
> cumbersome and cpu-hungry.  I've attached some previous work for your
> reference: an abstraction wmed5~.pd and test patch, and an external
> (from 2006) which needs to be fixed.  You'll see the external I wrote
> has int and float types everywhere (fine for 32-bit but it needs to be
> updated).  There's no guarantee the external will work as it is now,
> but I'll help with updating if you want to use it or part of it
>
> Chuck
>
>
>
> On Fri, Dec 23, 2016 at 4:52 PM, cyrille henry <ch at chnry.net> wrote:
>> thanks,
>> sort is indeed lost faster than an abstraction. but still to slow for an
>> audio rate median filter.
>> I guess it's worth writing an external for this task (that would benefit
>> from the fact that most input list are identical)
>>
>> cheers
>> c
>>
>>
>>
>> Le 23/12/2016 à 23:31, Christof Ressi a écrit :
>>>
>>> Hmmm. If doesn't have to be a vanilla solution, I would use zexy/sort and
>>> then get the middle element. It won't get much faster then that i guess.
>>>
>>>> Gesendet: Freitag, 23. Dezember 2016 um 23:17 Uhr
>>>> Von: "cyrille henry" <ch at chnry.net>
>>>> An: pd-list at lists.iem.at
>>>> Betreff: Re: [PD] array quantile problem
>>>>
>>>> Hhanks for the explanation.
>>>>
>>>> I think the "so for instance, the 0.5 quantile is the median of the
>>>> array." sentence of the documentation is confusion.
>>>>
>>>> anyway, is there a fast way to get the median of a list?
>>>> (faster than ordering the list with an abstraction and getting the middle
>>>> value)
>>>>
>>>>
>>>> thanks
>>>> Cyrille
>>>>
>>>>
>>>>
>>>> Le 23/12/2016 à 22:58, Christof Ressi a écrit :
>>>>>
>>>>> The array doesn't represent a list of values but rather a distribution
>>>>> of values where each y represents the weight of its x value. Changing your
>>>>> list to 1 2 3 4 5 6 7 8 9 will make it more clear to understand because the
>>>>> actual values are then: 0 1 1 2 2 2 3 3 3 3 4 4 4 4 4 5 5 5 5 5 5 6 6 6 6 6
>>>>> 6 6 7 7 7 7 7 7 7 7 8 8 8 8 8 8 8 8 8.  Therefore 6 is the correct median.
>>>>>
>>>>> Christof
>>>>>
>>>>>> Gesendet: Freitag, 23. Dezember 2016 um 21:55 Uhr
>>>>>> Von: "cyrille henry" <ch at chnry.net>
>>>>>> An: "pd-list at lists.iem.at" <pd-list at lists.iem.at>
>>>>>> Betreff: [PD] array quantile problem
>>>>>>
>>>>>> Hello,
>>>>>>
>>>>>> I'm trying to use the [array quantile] object, but it is not doing what
>>>>>> I understand from the documentation.
>>>>>> the help file specify that the 0.5 quantile is the median.
>>>>>> I'm using the wikipedia definition of the median :
>>>>>> https://en.wikipedia.org/wiki/Median
>>>>>>
>>>>>> So the list (0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9) admit 0.5 as median.
>>>>>>
>>>>>> [array quantile] return 6.
>>>>>>
>>>>>> In attachment, a patch that demonstrate this behaviours, and other list
>>>>>> that return value that I did not expect.
>>>>>>
>>>>>> I'm using pd 47.1.
>>>>>> Did I made something wrong, or is that just a bug in [array quantile]?
>>>>>>
>>>>>> cheers
>>>>>> C
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