[Cuis-dev] On ArrayedCollection >> incrementFraction

[Luciano Notarfrancesco]

But the two collectSlidingWindow: are not polymorphic, right? They expect
blocks that do different things? Or I’m confused?

On Thu, May 14, 2026 at 05:29 Francisco Garau <francisco.garau at gmail.com>
wrote:

> I've specialized the implementation of the #collectSlidingWindow: so that
> it uses the bulk primitives. As with the previous version there is a slight
> difference in behaviour as the resulting array is shorter than the original
> one. Performance wise, it should be the same as the current implementation.
> I've created a changeset but couldn't find how to make a PR out of it.
>
> This change makes it easier to add new sliding window operations of any
> size ... (all current examples are pairs but it could be triples or
> n-tuples).
>
> *SequenceableCollection >> collectSlidingWindow: aBlock*
>
> |  numArgs newSize result  slidingWindow |
> numArgs := aBlock numArgs.
> self size < numArgs ifTrue: [self errorCollectionTooSmall].
> newSize := self size - numArgs + 1.
>
> slidingWindow := Array new: numArgs.
> result := self species new: newSize.
> 1 to: newSize do: [ :index |
>
> 1 to: numArgs do: [:nArg | slidingWindow at: nArg put: (self at: index - 1
> + nArg)].
>
> result at: index put: (aBlock valueWithArguments: slidingWindow).].
>
> ^result
>
>
> *FloatArray>>collectSlidingWindow: aBlock*
>
> |  numArgs newSize  slidedArrays |
> numArgs := aBlock numArgs.
> self size < numArgs ifTrue: [self errorCollectionTooSmall].
> newSize := self size - numArgs + 1.
>
> slidedArrays := (1 to: numArgs) collect: [:index | | slided |
>
> slided := self species new: newSize.
>
> slided replaceFrom: 1 to: newSize with: self startingAt: index].
>
>
> ^aBlock valueWithArguments: slidedArrays
>
>
> *FloatArray >> slidingAdditions*
>
> "
> #(1 3 8 13) asFloat32Array slidingAdditions printString =  'a
> Float32Array:3(4.0 11.0 21.0)'.
> "
> ^self collectSlidingWindow: [:a :b | a += b ]
>
>
>
>
> On Wed, 13 May 2026 at 14:31, Luciano Notarfrancesco via Cuis-dev <
> cuis-dev at lists.cuis.st> wrote:
>
>> Hi Pancho,
>> Is it really more efficient? I think the idea of the original is to take
>> advantage of the bulk primitives in Float32Array and Float64Array, it
>> should be much faster (Although it contains a superfluous copy, it could be
>> improved a bit).
>>
>> On Wed, May 13, 2026 at 19:31 Francisco Garau via Cuis-dev <
>> cuis-dev at lists.cuis.st> wrote:
>>
>>> I've prepared a more generic and efficient implementation of these
>>> methods (with a small difference in behavior) -- I would prefer to submit
>>> this changes with a couple of PRs (one for the base image and one for the
>>> numerical package). Appreciate if there is any documentation for new
>>> contributions.
>>>
>>> #( 3 5 8 ) successiveRatios = { 1. 5/3 . 8/5} ." -- currently the first
>>> element is always 1 -- "
>>> #( 3 5 8 ) successiveRatios = { 5/3 . 8/5} . " -- the ratios will be
>>> calculated in between pairs --"
>>>
>>> *ArrayedCollection >> successiveRatios*
>>>
>>> "
>>> #( 3 5 8 ) successiveRatios = {5/3 . 8/5}.
>>> ([#(3) successiveRatios] on: Error do: [:ex | ex description ] ) =
>>> 'Error: this collection is too small'.
>>> "
>>> ^self collectSlidingWindow: [:a :b | b / a ]
>>>
>>>
>>>
>>> *SequenceableCollection >> collectSlidingWindow: aBlock*
>>>
>>> "
>>> (#( 3 5 8 13 ) collectSlidingWindow: [:a :b | a at b]) = {3 at 5 . 5 at 8 . 8 at 13
>>> }.
>>> (#( 3 5 8 13 ) collectSlidingWindow: [:a :b :c | {a. b. c}]) = {{3. 5.
>>> 8}. {5. 8. 13.}}.
>>> ('hello_word'  collectSlidingWindow: [:a | Character codePoint: a
>>> codePoint - 32]) = 'HELLO?WORD'.
>>>
>>> ([#(3) collectWithSlidingWindow: [:a :b | a + b]] on: Error do: [:ex |
>>> ex description]) = 'Error: this collection is too small'.
>>> "
>>> |  tupleSize newSize answer  blockArgs |
>>> tupleSize := aBlock numArgs.
>>> self size < tupleSize ifTrue: [self errorCollectionTooSmall].
>>> newSize := self size - tupleSize + 1.
>>> answer := self species new: newSize.
>>> blockArgs := Array new: tupleSize.
>>> 1 to: newSize do: [ :i |
>>> 1 to: tupleSize do: [:m | blockArgs at: m put: (self at: i + m -1 )].
>>> answer at: i put: (aBlock valueWithArguments: blockArgs).].
>>> ^ answer
>>>
>>>
>>>
>>> On Mon, 11 May 2026 at 20:12, Juan Vuletich via Cuis-dev <
>>> cuis-dev at lists.cuis.st> wrote:
>>>
>>>> Hi Ezequiel,
>>>>
>>>> (inline)
>>>> On 2026-05-03 1:48 AM, Ezequiel Birman via Cuis-dev wrote:
>>>>
>>>> Hi!,
>>>>
>>>> I want to collect the successive ratios in a collection of numbers in
>>>> order to appreciate how “fast” they grow. I noticed that the image already
>>>> implements ArrayedCollection >> incrementFraction, which is almost equal to
>>>> ArrayedCollection >> derivative:
>>>>
>>>> incrementFraction
>>>>> "
>>>>> #(10 12.5 15 20) incrementFraction
>>>>> "
>>>>> | displaced answer |
>>>>> displaced := self class new: self size.
>>>>> displaced replaceFrom: 2 to: self size with: self startingAt: 1.
>>>>> displaced at: 1 put: self first.
>>>>> answer := self copy.
>>>>> answer -= displaced.
>>>>
>>>> ^answer / displaced
>>>>
>>>>
>>>> derivative
>>>>> | displaced answer |
>>>>> displaced := self class new: self size.
>>>>> displaced replaceFrom: 2 to: self size with: self startingAt: 1.
>>>>> displaced at: 1 put: self first - self first. "Some reasonable zero"
>>>>> answer := self copy.
>>>>> answer -= displaced.
>>>>> ^answer
>>>>
>>>>
>>>> I think I want something similar, except for the subtraction:
>>>>
>>>>> myThing
>>>>>
>>>>> | displaced answer |
>>>>> displaced := self class new: self size.
>>>>> displaced replaceFrom: 2 to: self size with: self startingAt: 1.
>>>>> displaced at: 1 put: self first.
>>>>> answer := self copy.
>>>>
>>>> ^answer / displaced
>>>>
>>>>
>>>> I'll probably need both, since I'm doing exploratory analysis. And
>>>> while `myThing`, (which could be named `successiveRatios` or
>>>> something along those lines) can answer if there is a constant or varying
>>>> growth, `incrementFraction` measures the rate at which the growth itself is
>>>> scaling.
>>>>
>>>> This makes a lot of sense. I've just added your method with selector
>>>> #successiveRatios and your author initials. Thanks!
>>>>
>>>>
>>>> Neither `derivative` nor `incrementFraction` nor `Integral` have
>>>> senders. Juan, maybe you remember why or under which circumstances you
>>>> added them in 2024?
>>>>
>>>> I'd guess they are older than that. They are there because they are
>>>> ilustrative and could be of use. It is nice to have this kind of stuff in
>>>> the image. I believe it shows general Smalltalk-fu.
>>>>
>>>>  Are there any efforts / packages for numeric or data analysis?
>>>>
>>>>
>>>> Not specifically for that, but a good place for it would be
>>>> https://github.com/Cuis-Smalltalk/Numerics
>>>>
>>>> Cheers,
>>>>
>>>>
>>>> --
>>>> Eze
>>>>
>>>> --
>>>> Juan Vuletichwww.cuis.stgithub.com/jvuletichresearchgate.net/profile/Juan-Vuletichindependent.academia.edu/JuanVuletichpatents.justia.com/inventor/juan-manuel-vuletich
>>>>
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>>>>
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>
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