Nice :)

Cheers,
Karl

On Thu, Oct 25, 2018 at 6:34 PM Levente Uzonyi <leves at caesar.elte.hu> wrote:

> Hi Karl,
>
> The ultimate tool for such use case is Integer >> #primesUpTo:(do:).
> The code below is 3 times faster on my machine:
>
> form := Form extent:8000 at 8000.
> pen := Pen newOnForm: form.
> pen up.
> pen goto: 100 at 6000.
> pen down.
> pen turn: 90.
> pen color: Color black.
> previousPrime := nil.
> Integer primesUpTo: 5000000 do: [ :prime |
>         previousPrime ifNotNil: [
>                 pen
>                         go: prime - previousPrime;
>                         turn: 90 ].
>         previousPrime := prime ].
> form writePNGfileNamed: 'Sketch.png'
>
> Levente
>
> On Thu, 25 Oct 2018, karl ramberg wrote:
>
> > Cool. I was just playing with some random crackpot ideas yesterday which
> involved primes.
> > This fix made a nice speed up :-)
> >
> >    diff := OrderedCollection new.
> >    singular := 2.
> >    3 to: 5000000 do:[: i | i isPrime ifTrue:[ diff add: i - singular.
> > singular := i]].
> >   form := Form extent:8000 at 8000.
> >   pen := Pen newOnForm: form.
> >   pen up.
> >   pen goto: 100 at 6000.
> >   pen down.
> >   pen turn: 90.
> >   pen color: Color black.
> >   diff do:[:i | pen go: i. pen turn: 90].
> >   form writePNGfileNamed:  'Sketch.png'
> >
> > Cheers,
> > Karl
> >
> > On Wed, Oct 24, 2018 at 11:09 PM <commits at source.squeak.org> wrote:
> >       Levente Uzonyi uploaded a new version of Kernel to project The
> Trunk:
> >       http://source.squeak.org/trunk/Kernel-ul.1192.mcz
> >
> >       ==================== Summary ====================
> >
> >       Name: Kernel-ul.1192
> >       Author: ul
> >       Time: 24 October 2018, 10:50:43.875546 pm
> >       UUID: 72dfb776-3d77-4b84-9d69-d000e9a67ae1
> >       Ancestors: Kernel-eem.1191
> >
> >       - improved Integer >> #isPrime's performance
> >       - slightly faster Categorizer >> #numberOfCategoryOfElement:
> >
> >       =============== Diff against Kernel-eem.1191 ===============
> >
> >       Item was changed:
> >         ----- Method: Categorizer>>numberOfCategoryOfElement: (in
> category 'accessing') -----
> >         numberOfCategoryOfElement: element
> >               "Answer the index of the category with which the argument,
> element, is
> >               associated."
> >
> >       +       | categoryIndex elementIndex elementArraySize |
> >       -       | categoryIndex elementIndex |
> >               categoryIndex := 1.
> >               elementIndex := 0.
> >       +       elementArraySize := elementArray size.
> >       +       [(elementIndex := elementIndex + 1) <= elementArraySize]
> >       -       [(elementIndex := elementIndex + 1) <= elementArray size]
> >                       whileTrue:
> >                               ["point to correct category"
> >                               [elementIndex > (categoryStops at:
> categoryIndex)]
> >                                       whileTrue: [categoryIndex :=
> categoryIndex + 1].
> >                               "see if this is element"
> >                               element = (elementArray at: elementIndex)
> ifTrue: [^categoryIndex]].
> >               ^0!
> >
> >       Item was changed:
> >         ----- Method: Integer>>isPrime (in category 'testing') -----
> >         isPrime
> >               "Answer true if the receiver is a prime number. See
> isProbablyPrime for a probabilistic
> >               implementation that is much faster for large integers, and
> that is correct to an extremely
> >               high statistical level of confidence (effectively
> deterministic)."
> >
> >       +       | probe step limit |
> >       +       self <= 3 ifTrue: [ ^self >= 2 ].
> >       +       self \\ 2 = 0 ifTrue: [ ^false ].
> >       +       self \\ 3 = 0 ifTrue: [ ^false ].
> >       +       self <= 1073741823 ifFalse: [ "1 << 30 - 1. For numbers
> larger than this (on 64-bit platforms) #isProbablyPrime is usually quicker."
> >       -       self <= 1 ifTrue: [ ^false ].
> >       -       self even ifTrue: [ ^self = 2].
> >       -       self <= 1073741823 ifFalse: [ "1 << 30 - 1. For numbers
> larger than this, the calculation takes longer than #isProbablyPrime when
> the receiver is a prime. The absolue turning point
> >       is about at 1 << 35 - 1."
> >                       ^self isProbablyPrime ].
> >       +       probe := 5.
> >       +       step := 2. "Step will oscillate between 2 and 4 because at
> this point self \\ 6 is either 1 or 5."
> >       +       limit := self sqrtFloor. "On 64-bit platforms this could
> be written as self asFloat sqrt truncated (+ 1), which is faster because it
> creates no intermediate objects. Knowing that
> >       self has at most 30 bits because of the check above, this value
> will never be larger than 32767."
> >       +       [ probe <= limit ] whileTrue: [
> >       +               self \\ probe = 0 ifTrue: [ ^false ].
> >       +               probe := probe + step.
> >       +               step := 6 - step ].
> >       -       3 to: self sqrtFloor by: 2 do: [ :each |
> >       -               self \\ each = 0 ifTrue: [ ^false ] ].
> >               ^true!
> >
> >       Item was added:
> >       + ----- Method: LargeNegativeInteger>>isPrime (in category
> 'testing') -----
> >       + isPrime
> >       +
> >       +       ^false!
> >
> >
> >
> >
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.squeakfoundation.org/pipermail/squeak-dev/attachments/20181025/7a2f84d2/attachment.html>